Release 1.0.125

This is equivalent to looping 0..=u8::MAX, except that `..=` syntax is
not supported on old rustc and `...` syntax is not supported on new
rustc, so loop it is.

.github/ISSUE_TEMPLATE/4-discussion.md

@@ -1,7 +0,0 @@
----
-name: Help or discussion
-about: This is the right place
-
----
-
-

.github/workflows/ci.yml

@@ -109,6 +109,16 @@ jobs:
       - run: cd serde && cargo build --no-default-features
       - run: cd serde && cargo build
 
+  derive:
+    name: Rust 1.31.0
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: dtolnay/rust-toolchain@1.31.0
+      - run: cd serde && cargo check --no-default-features
+      - run: cd serde && cargo check
+      - run: cd serde_derive && cargo check
+
   alloc:
     name: Rust 1.36.0
     runs-on: ubuntu-latest
@@ -150,6 +160,7 @@ jobs:
         # https://github.com/rust-lang/rust-clippy/issues/5356
       - run: cd serde && cargo clippy --features rc,unstable -- -D clippy::all -A clippy::redundant_field_names
       - run: cd serde_derive && cargo clippy -- -D clippy::all
+      - run: cd serde_derive_internals && cargo clippy -- -D clippy::all
       - run: cd serde_test && cargo clippy -- -D clippy::all -A clippy::redundant_field_names
       - run: cd test_suite && cargo clippy --tests --features unstable -- -D clippy::all -A clippy::redundant_field_names
       - run: cd test_suite/no_std && cargo clippy -- -D clippy::all -A clippy::redundant_field_names

CONTRIBUTING.md

@@ -4,11 +4,6 @@ Serde welcomes contribution from everyone in the form of suggestions, bug
 reports, pull requests, and feedback. This document gives some guidance if you
 are thinking of helping us.
 
-Please reach out here in a GitHub issue or in the #serde IRC channel on
-[`irc.mozilla.org`] if we can do anything to help you contribute.
-
-[`irc.mozilla.org`]: https://wiki.mozilla.org/IRC
-
 ## Submitting bug reports and feature requests
 
 Serde development is spread across lots of repositories, but this serde-rs/serde
@@ -63,4 +58,4 @@ In all Serde-related forums, we follow the [Rust Code of Conduct]. For
 escalation or moderation issues please contact Erick (erick.tryzelaar@gmail.com)
 instead of the Rust moderation team.
 
-[Rust Code of Conduct]: https://www.rust-lang.org/conduct.html
+[Rust Code of Conduct]: https://www.rust-lang.org/policies/code-of-conduct

README.md

@@ -75,13 +75,23 @@ fn main() {
 
 ## Getting help
 
-Serde developers live in the #serde channel on [`irc.mozilla.org`][irc]. The
-\#rust channel is also a good resource with generally faster response time but
-less specific knowledge about Serde. If IRC is not your thing or you don't get a
-good response, we are happy to respond to [GitHub issues][issues] as well.
+Serde is one of the most widely used Rust libraries so any place that Rustaceans
+congregate will be able to help you out. For chat, consider trying the
+[#general] or [#beginners] channels of the unofficial community Discord, the
+[#rust-usage] channel of the official Rust Project Discord, or the
+[#general][zulip] stream in Zulip. For asynchronous, consider the [\[rust\] tag
+on StackOverflow][stackoverflow], the [/r/rust] subreddit which has a pinned
+weekly easy questions post, or the Rust [Discourse forum][discourse]. It's
+acceptable to file a support issue in this repo but they tend not to get as many
+eyes as any of the above and may get closed without a response after some time.
 
-[irc]: https://wiki.mozilla.org/IRC
-[issues]: https://github.com/serde-rs/serde/issues/new/choose
+[#general]: https://discord.com/channels/273534239310479360/274215136414400513
+[#beginners]: https://discord.com/channels/273534239310479360/273541522815713281
+[#rust-usage]: https://discord.com/channels/442252698964721669/443150878111694848
+[zulip]: https://rust-lang.zulipchat.com/#narrow/stream/122651-general
+[stackoverflow]: https://stackoverflow.com/questions/tagged/rust
+[/r/rust]: https://www.reddit.com/r/rust
+[discourse]: https://users.rust-lang.org
 
 <br>
 

crates-io.md

@@ -43,10 +43,20 @@ fn main() {
 
 ## Getting help
 
-Serde developers live in the #serde channel on [`irc.mozilla.org`][irc]. The
-\#rust channel is also a good resource with generally faster response time but
-less specific knowledge about Serde. If IRC is not your thing or you don't get a
-good response, we are happy to respond to [GitHub issues][issues] as well.
+Serde is one of the most widely used Rust libraries so any place that Rustaceans
+congregate will be able to help you out. For chat, consider trying the
+[#general] or [#beginners] channels of the unofficial community Discord, the
+[#rust-usage] channel of the official Rust Project Discord, or the
+[#general][zulip] stream in Zulip. For asynchronous, consider the [\[rust\] tag
+on StackOverflow][stackoverflow], the [/r/rust] subreddit which has a pinned
+weekly easy questions post, or the Rust [Discourse forum][discourse]. It's
+acceptable to file a support issue in this repo but they tend not to get as many
+eyes as any of the above and may get closed without a response after some time.
 
-[irc]: https://wiki.mozilla.org/IRC
-[issues]: https://github.com/serde-rs/serde/issues/new/choose
+[#general]: https://discord.com/channels/273534239310479360/274215136414400513
+[#beginners]: https://discord.com/channels/273534239310479360/273541522815713281
+[#rust-usage]: https://discord.com/channels/442252698964721669/443150878111694848
+[zulip]: https://rust-lang.zulipchat.com/#narrow/stream/122651-general
+[stackoverflow]: https://stackoverflow.com/questions/tagged/rust
+[/r/rust]: https://www.reddit.com/r/rust
+[discourse]: https://users.rust-lang.org

rustfmt.toml

@@ -1 +0,0 @@
-error_on_line_overflow = false

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.108" # remember to update html_root_url and serde_derive dependency
+version = "1.0.125" # remember to update html_root_url and serde_derive dependency
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT OR Apache-2.0"
 description = "A generic serialization/deserialization framework"
@@ -10,11 +10,11 @@ documentation = "https://docs.serde.rs/serde/"
 keywords = ["serde", "serialization", "no_std"]
 categories = ["encoding"]
 readme = "crates-io.md"
-include = ["Cargo.toml", "build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
+include = ["build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
 build = "build.rs"
 
 [dependencies]
-serde_derive = { version = "=1.0.108", optional = true, path = "../serde_derive" }
+serde_derive = { version = "=1.0.125", optional = true, path = "../serde_derive" }
 
 [dev-dependencies]
 serde_derive = { version = "1.0", path = "../serde_derive" }

serde/build.rs

@@ -66,17 +66,24 @@ fn main() {
     }
 
     // Non-zero integers stabilized in Rust 1.28:
-    // https://github.com/rust-lang/rust/pull/50808
+    // https://blog.rust-lang.org/2018/08/02/Rust-1.28.html#library-stabilizations
     if minor >= 28 {
         println!("cargo:rustc-cfg=num_nonzero");
     }
 
-    // TryFrom, Atomic types, and non-zero signed integers stabilized in Rust 1.34:
+    // Current minimum supported version of serde_derive crate is Rust 1.31.
+    if minor >= 31 {
+        println!("cargo:rustc-cfg=serde_derive");
+    }
+
+    // TryFrom, Atomic types, non-zero signed integers, and SystemTime::checked_add
+    // stabilized in Rust 1.34:
     // https://blog.rust-lang.org/2019/04/11/Rust-1.34.0.html#tryfrom-and-tryinto
     // https://blog.rust-lang.org/2019/04/11/Rust-1.34.0.html#library-stabilizations
     if minor >= 34 {
         println!("cargo:rustc-cfg=core_try_from");
         println!("cargo:rustc-cfg=num_nonzero_signed");
+        println!("cargo:rustc-cfg=systemtime_checked_add");
 
         // Whitelist of archs that support std::sync::atomic module. Ideally we
         // would use #[cfg(target_has_atomic = "...")] but it is not stable yet.

serde/src/de/from_primitive.rs

@@ -1,260 +0,0 @@
-use lib::*;
-
-macro_rules! int_to_int {
-    ($dst:ident, $n:ident) => {
-        if $dst::min_value() as i64 <= $n as i64 && $n as i64 <= $dst::max_value() as i64 {
-            Some($n as $dst)
-        } else {
-            None
-        }
-    };
-}
-
-macro_rules! int_to_uint {
-    ($dst:ident, $n:ident) => {
-        if 0 <= $n && $n as u64 <= $dst::max_value() as u64 {
-            Some($n as $dst)
-        } else {
-            None
-        }
-    };
-}
-
-macro_rules! uint_to {
-    ($dst:ident, $n:ident) => {
-        if $n as u64 <= $dst::max_value() as u64 {
-            Some($n as $dst)
-        } else {
-            None
-        }
-    };
-}
-
-pub trait FromPrimitive: Sized {
-    fn from_i8(n: i8) -> Option<Self>;
-    fn from_i16(n: i16) -> Option<Self>;
-    fn from_i32(n: i32) -> Option<Self>;
-    fn from_i64(n: i64) -> Option<Self>;
-    fn from_u8(n: u8) -> Option<Self>;
-    fn from_u16(n: u16) -> Option<Self>;
-    fn from_u32(n: u32) -> Option<Self>;
-    fn from_u64(n: u64) -> Option<Self>;
-}
-
-macro_rules! impl_from_primitive_for_int {
-    ($t:ident) => {
-        impl FromPrimitive for $t {
-            #[inline]
-            fn from_i8(n: i8) -> Option<Self> {
-                int_to_int!($t, n)
-            }
-            #[inline]
-            fn from_i16(n: i16) -> Option<Self> {
-                int_to_int!($t, n)
-            }
-            #[inline]
-            fn from_i32(n: i32) -> Option<Self> {
-                int_to_int!($t, n)
-            }
-            #[inline]
-            fn from_i64(n: i64) -> Option<Self> {
-                int_to_int!($t, n)
-            }
-            #[inline]
-            fn from_u8(n: u8) -> Option<Self> {
-                uint_to!($t, n)
-            }
-            #[inline]
-            fn from_u16(n: u16) -> Option<Self> {
-                uint_to!($t, n)
-            }
-            #[inline]
-            fn from_u32(n: u32) -> Option<Self> {
-                uint_to!($t, n)
-            }
-            #[inline]
-            fn from_u64(n: u64) -> Option<Self> {
-                uint_to!($t, n)
-            }
-        }
-    };
-}
-
-macro_rules! impl_from_primitive_for_uint {
-    ($t:ident) => {
-        impl FromPrimitive for $t {
-            #[inline]
-            fn from_i8(n: i8) -> Option<Self> {
-                int_to_uint!($t, n)
-            }
-            #[inline]
-            fn from_i16(n: i16) -> Option<Self> {
-                int_to_uint!($t, n)
-            }
-            #[inline]
-            fn from_i32(n: i32) -> Option<Self> {
-                int_to_uint!($t, n)
-            }
-            #[inline]
-            fn from_i64(n: i64) -> Option<Self> {
-                int_to_uint!($t, n)
-            }
-            #[inline]
-            fn from_u8(n: u8) -> Option<Self> {
-                uint_to!($t, n)
-            }
-            #[inline]
-            fn from_u16(n: u16) -> Option<Self> {
-                uint_to!($t, n)
-            }
-            #[inline]
-            fn from_u32(n: u32) -> Option<Self> {
-                uint_to!($t, n)
-            }
-            #[inline]
-            fn from_u64(n: u64) -> Option<Self> {
-                uint_to!($t, n)
-            }
-        }
-    };
-}
-
-macro_rules! impl_from_primitive_for_float {
-    ($t:ident) => {
-        impl FromPrimitive for $t {
-            #[inline]
-            fn from_i8(n: i8) -> Option<Self> {
-                Some(n as Self)
-            }
-            #[inline]
-            fn from_i16(n: i16) -> Option<Self> {
-                Some(n as Self)
-            }
-            #[inline]
-            fn from_i32(n: i32) -> Option<Self> {
-                Some(n as Self)
-            }
-            #[inline]
-            fn from_i64(n: i64) -> Option<Self> {
-                Some(n as Self)
-            }
-            #[inline]
-            fn from_u8(n: u8) -> Option<Self> {
-                Some(n as Self)
-            }
-            #[inline]
-            fn from_u16(n: u16) -> Option<Self> {
-                Some(n as Self)
-            }
-            #[inline]
-            fn from_u32(n: u32) -> Option<Self> {
-                Some(n as Self)
-            }
-            #[inline]
-            fn from_u64(n: u64) -> Option<Self> {
-                Some(n as Self)
-            }
-        }
-    };
-}
-
-impl_from_primitive_for_int!(isize);
-impl_from_primitive_for_int!(i8);
-impl_from_primitive_for_int!(i16);
-impl_from_primitive_for_int!(i32);
-impl_from_primitive_for_int!(i64);
-impl_from_primitive_for_uint!(usize);
-impl_from_primitive_for_uint!(u8);
-impl_from_primitive_for_uint!(u16);
-impl_from_primitive_for_uint!(u32);
-impl_from_primitive_for_uint!(u64);
-impl_from_primitive_for_float!(f32);
-impl_from_primitive_for_float!(f64);
-
-serde_if_integer128! {
-    impl FromPrimitive for i128 {
-        #[inline]
-        fn from_i8(n: i8) -> Option<Self> {
-            Some(n as i128)
-        }
-        #[inline]
-        fn from_i16(n: i16) -> Option<Self> {
-            Some(n as i128)
-        }
-        #[inline]
-        fn from_i32(n: i32) -> Option<Self> {
-            Some(n as i128)
-        }
-        #[inline]
-        fn from_i64(n: i64) -> Option<Self> {
-            Some(n as i128)
-        }
-        #[inline]
-        fn from_u8(n: u8) -> Option<Self> {
-            Some(n as i128)
-        }
-        #[inline]
-        fn from_u16(n: u16) -> Option<Self> {
-            Some(n as i128)
-        }
-        #[inline]
-        fn from_u32(n: u32) -> Option<Self> {
-            Some(n as i128)
-        }
-        #[inline]
-        fn from_u64(n: u64) -> Option<Self> {
-            Some(n as i128)
-        }
-    }
-
-    impl FromPrimitive for u128 {
-        #[inline]
-        fn from_i8(n: i8) -> Option<Self> {
-            if n >= 0 {
-                Some(n as u128)
-            } else {
-                None
-            }
-        }
-        #[inline]
-        fn from_i16(n: i16) -> Option<Self> {
-            if n >= 0 {
-                Some(n as u128)
-            } else {
-                None
-            }
-        }
-        #[inline]
-        fn from_i32(n: i32) -> Option<Self> {
-            if n >= 0 {
-                Some(n as u128)
-            } else {
-                None
-            }
-        }
-        #[inline]
-        fn from_i64(n: i64) -> Option<Self> {
-            if n >= 0 {
-                Some(n as u128)
-            } else {
-                None
-            }
-        }
-        #[inline]
-        fn from_u8(n: u8) -> Option<Self> {
-            Some(n as u128)
-        }
-        #[inline]
-        fn from_u16(n: u16) -> Option<Self> {
-            Some(n as u128)
-        }
-        #[inline]
-        fn from_u32(n: u32) -> Option<Self> {
-            Some(n as u128)
-        }
-        #[inline]
-        fn from_u64(n: u64) -> Option<Self> {
-            Some(n as u128)
-        }
-    }
-}

serde/src/de/ignored_any.rs

@@ -130,12 +130,28 @@ impl<'de> Visitor<'de> for IgnoredAny {
         Ok(IgnoredAny)
     }
 
+    serde_if_integer128! {
+        #[inline]
+        fn visit_i128<E>(self, x: i128) -> Result<Self::Value, E> {
+            let _ = x;
+            Ok(IgnoredAny)
+        }
+    }
+
     #[inline]
     fn visit_u64<E>(self, x: u64) -> Result<Self::Value, E> {
         let _ = x;
         Ok(IgnoredAny)
     }
 
+    serde_if_integer128! {
+        #[inline]
+        fn visit_u128<E>(self, x: u128) -> Result<Self::Value, E> {
+            let _ = x;
+            Ok(IgnoredAny)
+        }
+    }
+
     #[inline]
     fn visit_f64<E>(self, x: f64) -> Result<Self::Value, E> {
         let _ = x;

serde/src/de/impls.rs

@@ -7,11 +7,10 @@ use de::{
 #[cfg(any(core_duration, feature = "std", feature = "alloc"))]
 use de::MapAccess;
 
-use de::from_primitive::FromPrimitive;
-use private::de::InPlaceSeed;
+use seed::InPlaceSeed;
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-use private::de::size_hint;
+use __private::size_hint;
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -81,38 +80,8 @@ impl<'de> Deserialize<'de> for bool {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-macro_rules! visit_integer_method {
-    ($src_ty:ident, $method:ident, $from_method:ident, $group:ident, $group_ty:ident) => {
-        #[inline]
-        fn $method<E>(self, v: $src_ty) -> Result<Self::Value, E>
-        where
-            E: Error,
-        {
-            match FromPrimitive::$from_method(v) {
-                Some(v) => Ok(v),
-                None => Err(Error::invalid_value(
-                    Unexpected::$group(v as $group_ty),
-                    &self,
-                )),
-            }
-        }
-    };
-}
-
-macro_rules! visit_float_method {
-    ($src_ty:ident, $method:ident) => {
-        #[inline]
-        fn $method<E>(self, v: $src_ty) -> Result<Self::Value, E>
-        where
-            E: Error,
-        {
-            Ok(v as Self::Value)
-        }
-    };
-}
-
 macro_rules! impl_deserialize_num {
-    ($ty:ident, $method:ident, $($visit:ident),*) => {
+    ($ty:ident, $deserialize:ident $($methods:tt)*) => {
         impl<'de> Deserialize<'de> for $ty {
             #[inline]
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
@@ -128,131 +97,221 @@ macro_rules! impl_deserialize_num {
                         formatter.write_str(stringify!($ty))
                     }
 
-                    $(
-                        impl_deserialize_num!($visit $ty);
-                    )*
+                    $($methods)*
                 }
 
-                deserializer.$method(PrimitiveVisitor)
+                deserializer.$deserialize(PrimitiveVisitor)
             }
         }
     };
-
-    (integer $ty:ident) => {
-        visit_integer_method!(i8, visit_i8, from_i8, Signed, i64);
-        visit_integer_method!(i16, visit_i16, from_i16, Signed, i64);
-        visit_integer_method!(i32, visit_i32, from_i32, Signed, i64);
-        visit_integer_method!(i64, visit_i64, from_i64, Signed, i64);
-
-        visit_integer_method!(u8, visit_u8, from_u8, Unsigned, u64);
-        visit_integer_method!(u16, visit_u16, from_u16, Unsigned, u64);
-        visit_integer_method!(u32, visit_u32, from_u32, Unsigned, u64);
-        visit_integer_method!(u64, visit_u64, from_u64, Unsigned, u64);
-    };
-
-    (float $ty:ident) => {
-        visit_float_method!(f32, visit_f32);
-        visit_float_method!(f64, visit_f64);
-    };
 }
 
-impl_deserialize_num!(i8, deserialize_i8, integer);
-impl_deserialize_num!(i16, deserialize_i16, integer);
-impl_deserialize_num!(i32, deserialize_i32, integer);
-impl_deserialize_num!(i64, deserialize_i64, integer);
-impl_deserialize_num!(isize, deserialize_i64, integer);
-
-impl_deserialize_num!(u8, deserialize_u8, integer);
-impl_deserialize_num!(u16, deserialize_u16, integer);
-impl_deserialize_num!(u32, deserialize_u32, integer);
-impl_deserialize_num!(u64, deserialize_u64, integer);
-impl_deserialize_num!(usize, deserialize_u64, integer);
-
-impl_deserialize_num!(f32, deserialize_f32, integer, float);
-impl_deserialize_num!(f64, deserialize_f64, integer, float);
-
-serde_if_integer128! {
-    impl<'de> Deserialize<'de> for i128 {
+macro_rules! num_self {
+    ($ty:ident : $visit:ident) => {
         #[inline]
-        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
         where
-            D: Deserializer<'de>,
+            E: Error,
         {
-            struct PrimitiveVisitor;
+            Ok(v)
+        }
+    };
+}
 
-            impl<'de> Visitor<'de> for PrimitiveVisitor {
-                type Value = i128;
+macro_rules! num_as_self {
+    ($($ty:ident : $visit:ident)*) => {
+        $(
+            #[inline]
+            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+            where
+                E: Error,
+            {
+                Ok(v as Self::Value)
+            }
+        )*
+    };
+}
 
-                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                    formatter.write_str("i128")
-                }
-
-                impl_deserialize_num!(integer i128);
-
-                #[inline]
-                fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
-                where
-                    E: Error,
-                {
-                    Ok(v)
-                }
-
-                #[inline]
-                fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
-                where
-                    E: Error,
-                {
-                    if v <= i128::max_value() as u128 {
-                        Ok(v as i128)
-                    } else {
-                        Err(Error::invalid_value(Unexpected::Other("u128"), &self))
-                    }
+macro_rules! int_to_int {
+    ($($ty:ident : $visit:ident)*) => {
+        $(
+            #[inline]
+            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+            where
+                E: Error,
+            {
+                if Self::Value::min_value() as i64 <= v as i64 && v as i64 <= Self::Value::max_value() as i64 {
+                    Ok(v as Self::Value)
+                } else {
+                    Err(Error::invalid_value(Unexpected::Signed(v as i64), &self))
                 }
             }
+        )*
+    };
+}
 
-            deserializer.deserialize_i128(PrimitiveVisitor)
+macro_rules! int_to_uint {
+    ($($ty:ident : $visit:ident)*) => {
+        $(
+            #[inline]
+            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+            where
+                E: Error,
+            {
+                if 0 <= v && v as u64 <= Self::Value::max_value() as u64 {
+                    Ok(v as Self::Value)
+                } else {
+                    Err(Error::invalid_value(Unexpected::Signed(v as i64), &self))
+                }
+            }
+        )*
+    };
+}
+
+macro_rules! uint_to_self {
+    ($($ty:ident : $visit:ident)*) => {
+        $(
+            #[inline]
+            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+            where
+                E: Error,
+            {
+                if v as u64 <= Self::Value::max_value() as u64 {
+                    Ok(v as Self::Value)
+                } else {
+                    Err(Error::invalid_value(Unexpected::Unsigned(v as u64), &self))
+                }
+            }
+        )*
+    };
+}
+
+impl_deserialize_num! {
+    i8, deserialize_i8
+    num_self!(i8:visit_i8);
+    int_to_int!(i16:visit_i16 i32:visit_i32 i64:visit_i64);
+    uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    i16, deserialize_i16
+    num_self!(i16:visit_i16);
+    num_as_self!(i8:visit_i8);
+    int_to_int!(i32:visit_i32 i64:visit_i64);
+    uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    i32, deserialize_i32
+    num_self!(i32:visit_i32);
+    num_as_self!(i8:visit_i8 i16:visit_i16);
+    int_to_int!(i64:visit_i64);
+    uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    i64, deserialize_i64
+    num_self!(i64:visit_i64);
+    num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32);
+    uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    isize, deserialize_i64
+    num_as_self!(i8:visit_i8 i16:visit_i16);
+    int_to_int!(i32:visit_i32 i64:visit_i64);
+    uint_to_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    u8, deserialize_u8
+    num_self!(u8:visit_u8);
+    int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+    uint_to_self!(u16:visit_u16 u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    u16, deserialize_u16
+    num_self!(u16:visit_u16);
+    num_as_self!(u8:visit_u8);
+    int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+    uint_to_self!(u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    u32, deserialize_u32
+    num_self!(u32:visit_u32);
+    num_as_self!(u8:visit_u8 u16:visit_u16);
+    int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+    uint_to_self!(u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    u64, deserialize_u64
+    num_self!(u64:visit_u64);
+    num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32);
+    int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+}
+
+impl_deserialize_num! {
+    usize, deserialize_u64
+    num_as_self!(u8:visit_u8 u16:visit_u16);
+    int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+    uint_to_self!(u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    f32, deserialize_f32
+    num_self!(f32:visit_f32);
+    num_as_self!(f64:visit_f64);
+    num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+    num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+}
+
+impl_deserialize_num! {
+    f64, deserialize_f64
+    num_self!(f64:visit_f64);
+    num_as_self!(f32:visit_f32);
+    num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+    num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+}
+
+serde_if_integer128! {
+    impl_deserialize_num! {
+        i128, deserialize_i128
+        num_self!(i128:visit_i128);
+        num_as_self!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+        num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+
+        #[inline]
+        fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if v <= i128::max_value() as u128 {
+                Ok(v as i128)
+            } else {
+                Err(Error::invalid_value(Unexpected::Other("u128"), &self))
+            }
         }
     }
 
-    impl<'de> Deserialize<'de> for u128 {
+    impl_deserialize_num! {
+        u128, deserialize_u128
+        num_self!(u128:visit_u128);
+        num_as_self!(u8:visit_u8 u16:visit_u16 u32:visit_u32 u64:visit_u64);
+        int_to_uint!(i8:visit_i8 i16:visit_i16 i32:visit_i32 i64:visit_i64);
+
         #[inline]
-        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
         where
-            D: Deserializer<'de>,
+            E: Error,
         {
-            struct PrimitiveVisitor;
-
-            impl<'de> Visitor<'de> for PrimitiveVisitor {
-                type Value = u128;
-
-                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                    formatter.write_str("u128")
-                }
-
-                impl_deserialize_num!(integer u128);
-
-                #[inline]
-                fn visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
-                where
-                    E: Error,
-                {
-                    if v >= 0 {
-                        Ok(v as u128)
-                    } else {
-                        Err(Error::invalid_value(Unexpected::Other("i128"), &self))
-                    }
-                }
-
-                #[inline]
-                fn visit_u128<E>(self, v: u128) -> Result<Self::Value, E>
-                where
-                    E: Error,
-                {
-                    Ok(v)
-                }
+            if 0 <= v {
+                Ok(v as u128)
+            } else {
+                Err(Error::invalid_value(Unexpected::Other("i128"), &self))
             }
-
-            deserializer.deserialize_u128(PrimitiveVisitor)
         }
     }
 }
@@ -1260,24 +1319,7 @@ macro_rules! parse_ip_impl {
                 D: Deserializer<'de>,
             {
                 if deserializer.is_human_readable() {
-                    struct IpAddrVisitor;
-
-                    impl<'de> Visitor<'de> for IpAddrVisitor {
-                        type Value = $ty;
-
-                        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                            formatter.write_str($expecting)
-                        }
-
-                        fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
-                        where
-                            E: Error,
-                        {
-                            s.parse().map_err(Error::custom)
-                        }
-                    }
-
-                    deserializer.deserialize_str(IpAddrVisitor)
+                    deserializer.deserialize_str(FromStrVisitor::new($expecting))
                 } else {
                     <[u8; $size]>::deserialize(deserializer).map(<$ty>::from)
                 }
@@ -1313,7 +1355,7 @@ macro_rules! variant_identifier {
                         formatter.write_str($expecting_message)
                     }
 
-                    fn visit_u32<E>(self, value: u32) -> Result<Self::Value, E>
+                    fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E>
                     where
                         E: Error,
                     {
@@ -1321,7 +1363,7 @@ macro_rules! variant_identifier {
                             $(
                                 $index => Ok($name_kind :: $variant),
                             )*
-                            _ => Err(Error::invalid_value(Unexpected::Unsigned(value as u64), &self),),
+                            _ => Err(Error::invalid_value(Unexpected::Unsigned(value), &self),),
                         }
                     }
 
@@ -1405,24 +1447,7 @@ impl<'de> Deserialize<'de> for net::IpAddr {
         D: Deserializer<'de>,
     {
         if deserializer.is_human_readable() {
-            struct IpAddrVisitor;
-
-            impl<'de> Visitor<'de> for IpAddrVisitor {
-                type Value = net::IpAddr;
-
-                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                    formatter.write_str("IP address")
-                }
-
-                fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
-                where
-                    E: Error,
-                {
-                    s.parse().map_err(Error::custom)
-                }
-            }
-
-            deserializer.deserialize_str(IpAddrVisitor)
+            deserializer.deserialize_str(FromStrVisitor::new("IP address"))
         } else {
             use lib::net::IpAddr;
             deserialize_enum! {
@@ -1449,24 +1474,7 @@ macro_rules! parse_socket_impl {
                 D: Deserializer<'de>,
             {
                 if deserializer.is_human_readable() {
-                    struct SocketAddrVisitor;
-
-                    impl<'de> Visitor<'de> for SocketAddrVisitor {
-                        type Value = $ty;
-
-                        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                            formatter.write_str($expecting)
-                        }
-
-                        fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
-                        where
-                            E: Error,
-                        {
-                            s.parse().map_err(Error::custom)
-                        }
-                    }
-
-                    deserializer.deserialize_str(SocketAddrVisitor)
+                    deserializer.deserialize_str(FromStrVisitor::new($expecting))
                 } else {
                     <(_, u16)>::deserialize(deserializer).map(|(ip, port)| $new(ip, port))
                 }
@@ -1482,24 +1490,7 @@ impl<'de> Deserialize<'de> for net::SocketAddr {
         D: Deserializer<'de>,
     {
         if deserializer.is_human_readable() {
-            struct SocketAddrVisitor;
-
-            impl<'de> Visitor<'de> for SocketAddrVisitor {
-                type Value = net::SocketAddr;
-
-                fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                    formatter.write_str("socket address")
-                }
-
-                fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
-                where
-                    E: Error,
-                {
-                    s.parse().map_err(Error::custom)
-                }
-            }
-
-            deserializer.deserialize_str(SocketAddrVisitor)
+            deserializer.deserialize_str(FromStrVisitor::new("socket address"))
         } else {
             use lib::net::SocketAddr;
             deserialize_enum! {
@@ -1871,7 +1862,7 @@ impl<'de> Deserialize<'de> for Duration {
         enum Field {
             Secs,
             Nanos,
-        };
+        }
 
         impl<'de> Deserialize<'de> for Field {
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
@@ -1906,7 +1897,7 @@ impl<'de> Deserialize<'de> for Duration {
                             b"secs" => Ok(Field::Secs),
                             b"nanos" => Ok(Field::Nanos),
                             _ => {
-                                let value = ::export::from_utf8_lossy(value);
+                                let value = ::__private::from_utf8_lossy(value);
                                 Err(Error::unknown_field(&value, FIELDS))
                             }
                         }
@@ -1917,6 +1908,17 @@ impl<'de> Deserialize<'de> for Duration {
             }
         }
 
+        fn check_overflow<E>(secs: u64, nanos: u32) -> Result<(), E>
+        where
+            E: Error,
+        {
+            static NANOS_PER_SEC: u32 = 1_000_000_000;
+            match secs.checked_add((nanos / NANOS_PER_SEC) as u64) {
+                Some(_) => Ok(()),
+                None => Err(E::custom("overflow deserializing Duration")),
+            }
+        }
+
         struct DurationVisitor;
 
         impl<'de> Visitor<'de> for DurationVisitor {
@@ -1942,6 +1944,7 @@ impl<'de> Deserialize<'de> for Duration {
                         return Err(Error::invalid_length(1, &self));
                     }
                 };
+                try!(check_overflow(secs, nanos));
                 Ok(Duration::new(secs, nanos))
             }
 
@@ -1975,6 +1978,7 @@ impl<'de> Deserialize<'de> for Duration {
                     Some(nanos) => nanos,
                     None => return Err(<A::Error as Error>::missing_field("nanos")),
                 };
+                try!(check_overflow(secs, nanos));
                 Ok(Duration::new(secs, nanos))
             }
         }
@@ -1996,7 +2000,7 @@ impl<'de> Deserialize<'de> for SystemTime {
         enum Field {
             Secs,
             Nanos,
-        };
+        }
 
         impl<'de> Deserialize<'de> for Field {
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
@@ -2042,6 +2046,17 @@ impl<'de> Deserialize<'de> for SystemTime {
             }
         }
 
+        fn check_overflow<E>(secs: u64, nanos: u32) -> Result<(), E>
+        where
+            E: Error,
+        {
+            static NANOS_PER_SEC: u32 = 1_000_000_000;
+            match secs.checked_add((nanos / NANOS_PER_SEC) as u64) {
+                Some(_) => Ok(()),
+                None => Err(E::custom("overflow deserializing SystemTime epoch offset")),
+            }
+        }
+
         struct DurationVisitor;
 
         impl<'de> Visitor<'de> for DurationVisitor {
@@ -2067,6 +2082,7 @@ impl<'de> Deserialize<'de> for SystemTime {
                         return Err(Error::invalid_length(1, &self));
                     }
                 };
+                try!(check_overflow(secs, nanos));
                 Ok(Duration::new(secs, nanos))
             }
 
@@ -2104,13 +2120,20 @@ impl<'de> Deserialize<'de> for SystemTime {
                     Some(nanos) => nanos,
                     None => return Err(<A::Error as Error>::missing_field("nanos_since_epoch")),
                 };
+                try!(check_overflow(secs, nanos));
                 Ok(Duration::new(secs, nanos))
             }
         }
 
         const FIELDS: &'static [&'static str] = &["secs_since_epoch", "nanos_since_epoch"];
         let duration = try!(deserializer.deserialize_struct("SystemTime", FIELDS, DurationVisitor));
-        Ok(UNIX_EPOCH + duration)
+        #[cfg(systemtime_checked_add)]
+        let ret = UNIX_EPOCH
+            .checked_add(duration)
+            .ok_or_else(|| D::Error::custom("overflow deserializing SystemTime"));
+        #[cfg(not(systemtime_checked_add))]
+        let ret = Ok(UNIX_EPOCH + duration);
+        ret
     }
 }
 
@@ -2214,7 +2237,7 @@ mod range {
                         b"start" => Ok(Field::Start),
                         b"end" => Ok(Field::End),
                         _ => {
-                            let value = ::export::from_utf8_lossy(value);
+                            let value = ::__private::from_utf8_lossy(value);
                             Err(Error::unknown_field(&value, FIELDS))
                         }
                     }
@@ -2326,7 +2349,7 @@ where
                         formatter.write_str("`Unbounded`, `Included` or `Excluded`")
                     }
 
-                    fn visit_u32<E>(self, value: u32) -> Result<Self::Value, E>
+                    fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E>
                     where
                         E: Error,
                     {
@@ -2334,10 +2357,7 @@ where
                             0 => Ok(Field::Unbounded),
                             1 => Ok(Field::Included),
                             2 => Ok(Field::Excluded),
-                            _ => Err(Error::invalid_value(
-                                Unexpected::Unsigned(value as u64),
-                                &self,
-                            )),
+                            _ => Err(Error::invalid_value(Unexpected::Unsigned(value), &self)),
                         }
                     }
 
@@ -2492,17 +2512,14 @@ where
                         formatter.write_str("`Ok` or `Err`")
                     }
 
-                    fn visit_u32<E>(self, value: u32) -> Result<Self::Value, E>
+                    fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E>
                     where
                         E: Error,
                     {
                         match value {
                             0 => Ok(Field::Ok),
                             1 => Ok(Field::Err),
-                            _ => Err(Error::invalid_value(
-                                Unexpected::Unsigned(value as u64),
-                                &self,
-                            )),
+                            _ => Err(Error::invalid_value(Unexpected::Unsigned(value), &self)),
                         }
                     }
 
@@ -2570,7 +2587,6 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(feature = "std")]
 impl<'de, T> Deserialize<'de> for Wrapping<T>
 where
     T: Deserialize<'de>,
@@ -2610,3 +2626,39 @@ atomic_impl! {
 atomic_impl! {
     AtomicI64 AtomicU64
 }
+
+#[cfg(feature = "std")]
+struct FromStrVisitor<T> {
+    expecting: &'static str,
+    ty: PhantomData<T>,
+}
+
+#[cfg(feature = "std")]
+impl<T> FromStrVisitor<T> {
+    fn new(expecting: &'static str) -> Self {
+        FromStrVisitor {
+            expecting: expecting,
+            ty: PhantomData,
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl<'de, T> Visitor<'de> for FromStrVisitor<T>
+where
+    T: str::FromStr,
+    T::Err: fmt::Display,
+{
+    type Value = T;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str(self.expecting)
+    }
+
+    fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        s.parse().map_err(Error::custom)
+    }
+}

serde/src/de/mod.rs

@@ -104,7 +104,7 @@
 //! [`Deserialize`]: ../trait.Deserialize.html
 //! [`Deserializer`]: ../trait.Deserializer.html
 //! [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html
-//! [`bincode`]: https://github.com/TyOverby/bincode
+//! [`bincode`]: https://github.com/servo/bincode
 //! [`linked-hash-map`]: https://crates.io/crates/linked-hash-map
 //! [`serde_derive`]: https://crates.io/crates/serde_derive
 //! [`serde_json`]: https://github.com/serde-rs/json
@@ -118,7 +118,6 @@ use lib::*;
 
 pub mod value;
 
-mod from_primitive;
 mod ignored_any;
 mod impls;
 mod utf8;
@@ -393,7 +392,7 @@ pub enum Unexpected<'a> {
 }
 
 impl<'a> fmt::Display for Unexpected<'a> {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         use self::Unexpected::*;
         match *self {
             Bool(b) => write!(formatter, "boolean `{}`", b),

serde/src/de/seed.rs

@@ -0,0 +1,19 @@
+use de::{Deserialize, DeserializeSeed, Deserializer};
+
+/// A DeserializeSeed helper for implementing deserialize_in_place Visitors.
+///
+/// Wraps a mutable reference and calls deserialize_in_place on it.
+pub struct InPlaceSeed<'a, T: 'a>(pub &'a mut T);
+
+impl<'a, 'de, T> DeserializeSeed<'de> for InPlaceSeed<'a, T>
+where
+    T: Deserialize<'de>,
+{
+    type Value = ();
+    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        T::deserialize_in_place(deserializer, self.0)
+    }
+}

serde/src/de/value.rs

@@ -24,8 +24,8 @@
 use lib::*;
 
 use self::private::{First, Second};
-use de::{self, Expected, IntoDeserializer, SeqAccess};
-use private::de::size_hint;
+use __private::size_hint;
+use de::{self, Deserializer, Expected, IntoDeserializer, SeqAccess, Visitor};
 use ser;
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -48,7 +48,7 @@ macro_rules! impl_copy_clone {
 
 /// A minimal representation of all possible errors that can occur using the
 /// `IntoDeserializer` trait.
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, PartialEq)]
 pub struct Error {
     err: ErrorImpl,
 }
@@ -93,16 +93,25 @@ impl ser::Error for Error {
 
 impl Display for Error {
     #[cfg(any(feature = "std", feature = "alloc"))]
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         formatter.write_str(&self.err)
     }
 
     #[cfg(not(any(feature = "std", feature = "alloc")))]
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         formatter.write_str("Serde deserialization error")
     }
 }
 
+impl Debug for Error {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut debug = formatter.debug_tuple("Error");
+        #[cfg(any(feature = "std", feature = "alloc"))]
+        debug.field(&self.err);
+        debug.finish()
+    }
+}
+
 #[cfg(feature = "std")]
 impl error::Error for Error {
     fn description(&self) -> &str {
@@ -126,7 +135,6 @@ where
 }
 
 /// A deserializer holding a `()`.
-#[derive(Debug)]
 pub struct UnitDeserializer<E> {
     marker: PhantomData<E>,
 }
@@ -160,6 +168,12 @@ where
     }
 }
 
+impl<E> Debug for UnitDeserializer<E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.debug_struct("UnitDeserializer").finish()
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /// A deserializer that cannot be instantiated.
@@ -208,7 +222,6 @@ macro_rules! primitive_deserializer {
     ($ty:ty, $doc:tt, $name:ident, $method:ident $($cast:tt)*) => {
         #[doc = "A deserializer holding"]
         #[doc = $doc]
-        #[derive(Debug)]
         pub struct $name<E> {
             value: $ty,
             marker: PhantomData<E>
@@ -249,6 +262,15 @@ macro_rules! primitive_deserializer {
                 visitor.$method(self.value $($cast)*)
             }
         }
+
+        impl<E> Debug for $name<E> {
+            fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                formatter
+                    .debug_struct(stringify!($name))
+                    .field("value", &self.value)
+                    .finish()
+            }
+        }
     }
 }
 
@@ -272,7 +294,6 @@ serde_if_integer128! {
 }
 
 /// A deserializer holding a `u32`.
-#[derive(Debug)]
 pub struct U32Deserializer<E> {
     value: u32,
     marker: PhantomData<E>,
@@ -343,10 +364,18 @@ where
     }
 }
 
+impl<E> Debug for U32Deserializer<E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_struct("U32Deserializer")
+            .field("value", &self.value)
+            .finish()
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /// A deserializer holding a `&str`.
-#[derive(Debug)]
 pub struct StrDeserializer<'a, E> {
     value: &'a str,
     marker: PhantomData<E>,
@@ -417,11 +446,19 @@ where
     }
 }
 
+impl<'a, E> Debug for StrDeserializer<'a, E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_struct("StrDeserializer")
+            .field("value", &self.value)
+            .finish()
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /// A deserializer holding a `&str` with a lifetime tied to another
 /// deserializer.
-#[derive(Debug)]
 pub struct BorrowedStrDeserializer<'de, E> {
     value: &'de str,
     marker: PhantomData<E>,
@@ -488,11 +525,19 @@ where
     }
 }
 
+impl<'de, E> Debug for BorrowedStrDeserializer<'de, E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_struct("BorrowedStrDeserializer")
+            .field("value", &self.value)
+            .finish()
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /// A deserializer holding a `String`.
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[derive(Debug)]
 pub struct StringDeserializer<E> {
     value: String,
     marker: PhantomData<E>,
@@ -574,11 +619,20 @@ where
     }
 }
 
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<E> Debug for StringDeserializer<E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_struct("StringDeserializer")
+            .field("value", &self.value)
+            .finish()
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /// A deserializer holding a `Cow<str>`.
 #[cfg(any(feature = "std", feature = "alloc"))]
-#[derive(Debug)]
 pub struct CowStrDeserializer<'a, E> {
     value: Cow<'a, str>,
     marker: PhantomData<E>,
@@ -663,29 +717,48 @@ where
     }
 }
 
+#[cfg(any(feature = "std", feature = "alloc"))]
+impl<'a, E> Debug for CowStrDeserializer<'a, E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_struct("CowStrDeserializer")
+            .field("value", &self.value)
+            .finish()
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
-/// A deserializer holding a `&[u8]` with a lifetime tied to another
-/// deserializer.
-#[derive(Debug)]
-pub struct BorrowedBytesDeserializer<'de, E> {
-    value: &'de [u8],
+/// A deserializer holding a `&[u8]`. Always calls [`Visitor::visit_bytes`].
+pub struct BytesDeserializer<'a, E> {
+    value: &'a [u8],
     marker: PhantomData<E>,
 }
 
-impl_copy_clone!(BorrowedBytesDeserializer<'de>);
-
-impl<'de, E> BorrowedBytesDeserializer<'de, E> {
-    /// Create a new borrowed deserializer from the given byte slice.
-    pub fn new(value: &'de [u8]) -> BorrowedBytesDeserializer<'de, E> {
-        BorrowedBytesDeserializer {
+impl<'a, E> BytesDeserializer<'a, E> {
+    /// Create a new deserializer from the given bytes.
+    pub fn new(value: &'a [u8]) -> Self {
+        BytesDeserializer {
             value: value,
             marker: PhantomData,
         }
     }
 }
 
-impl<'de, E> de::Deserializer<'de> for BorrowedBytesDeserializer<'de, E>
+impl_copy_clone!(BytesDeserializer<'a>);
+
+impl<'de, 'a, E> IntoDeserializer<'de, E> for &'a [u8]
+where
+    E: de::Error,
+{
+    type Deserializer = BytesDeserializer<'a, E>;
+
+    fn into_deserializer(self) -> BytesDeserializer<'a, E> {
+        BytesDeserializer::new(self)
+    }
+}
+
+impl<'de, 'a, E> Deserializer<'de> for BytesDeserializer<'a, E>
 where
     E: de::Error,
 {
@@ -693,7 +766,55 @@ where
 
     fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
     where
-        V: de::Visitor<'de>,
+        V: Visitor<'de>,
+    {
+        visitor.visit_bytes(self.value)
+    }
+
+    forward_to_deserialize_any! {
+        bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
+        bytes byte_buf option unit unit_struct newtype_struct seq tuple
+        tuple_struct map struct enum identifier ignored_any
+    }
+}
+
+impl<'a, E> Debug for BytesDeserializer<'a, E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_struct("BytesDeserializer")
+            .field("value", &self.value)
+            .finish()
+    }
+}
+
+/// A deserializer holding a `&[u8]` with a lifetime tied to another
+/// deserializer. Always calls [`Visitor::visit_borrowed_bytes`].
+pub struct BorrowedBytesDeserializer<'de, E> {
+    value: &'de [u8],
+    marker: PhantomData<E>,
+}
+
+impl<'de, E> BorrowedBytesDeserializer<'de, E> {
+    /// Create a new borrowed deserializer from the given borrowed bytes.
+    pub fn new(value: &'de [u8]) -> Self {
+        BorrowedBytesDeserializer {
+            value: value,
+            marker: PhantomData,
+        }
+    }
+}
+
+impl_copy_clone!(BorrowedBytesDeserializer<'de>);
+
+impl<'de, E> Deserializer<'de> for BorrowedBytesDeserializer<'de, E>
+where
+    E: de::Error,
+{
+    type Error = E;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
     {
         visitor.visit_borrowed_bytes(self.value)
     }
@@ -701,14 +822,23 @@ where
     forward_to_deserialize_any! {
         bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
         bytes byte_buf option unit unit_struct newtype_struct seq tuple
-        tuple_struct map struct identifier ignored_any enum
+        tuple_struct map struct enum identifier ignored_any
+    }
+}
+
+impl<'de, E> Debug for BorrowedBytesDeserializer<'de, E> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_struct("BorrowedBytesDeserializer")
+            .field("value", &self.value)
+            .finish()
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 /// A deserializer that iterates over a sequence.
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub struct SeqDeserializer<I, E> {
     iter: iter::Fuse<I>,
     count: usize,
@@ -813,6 +943,19 @@ impl Expected for ExpectedInSeq {
     }
 }
 
+impl<I, E> Debug for SeqDeserializer<I, E>
+where
+    I: Debug,
+{
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter
+            .debug_struct("SeqDeserializer")
+            .field("iter", &self.iter)
+            .field("count", &self.count)
+            .finish()
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 #[cfg(any(feature = "std", feature = "alloc"))]
@@ -1034,7 +1177,7 @@ where
         let value = self.value.take();
         // Panic because this indicates a bug in the program rather than an
         // expected failure.
-        let value = value.expect("MapAccess::visit_value called before visit_key");
+        let value = value.expect("MapAccess::next_value called before next_key");
         seed.deserialize(value.into_deserializer())
     }
 
@@ -1108,7 +1251,6 @@ where
     }
 }
 
-// Cannot #[derive(Debug)] because of the bound `Second<I::Item>: Debug`.
 impl<'de, I, E> Debug for MapDeserializer<'de, I, E>
 where
     I: Iterator + Debug,
@@ -1121,8 +1263,6 @@ where
             .field("iter", &self.iter)
             .field("value", &self.value)
             .field("count", &self.count)
-            .field("lifetime", &self.lifetime)
-            .field("error", &self.error)
             .finish()
     }
 }
@@ -1331,7 +1471,6 @@ mod private {
 
     use de::{self, DeserializeSeed, Deserializer, MapAccess, Unexpected, VariantAccess, Visitor};
 
-    #[derive(Clone, Debug)]
     pub struct UnitOnly<E> {
         marker: PhantomData<E>,
     }
@@ -1390,7 +1529,6 @@ mod private {
         }
     }
 
-    #[derive(Clone, Debug)]
     pub struct MapAsEnum<A> {
         map: A,
     }

serde/src/export.rs

@@ -1,39 +0,0 @@
-pub use lib::clone::Clone;
-pub use lib::convert::{From, Into};
-pub use lib::default::Default;
-pub use lib::fmt::{self, Formatter};
-pub use lib::marker::PhantomData;
-pub use lib::option::Option::{self, None, Some};
-pub use lib::result::Result::{self, Err, Ok};
-
-pub use self::string::from_utf8_lossy;
-
-#[cfg(any(feature = "alloc", feature = "std"))]
-pub use lib::{ToString, Vec};
-
-#[cfg(core_try_from)]
-pub use lib::convert::TryFrom;
-
-mod string {
-    use lib::*;
-
-    #[cfg(any(feature = "std", feature = "alloc"))]
-    pub fn from_utf8_lossy(bytes: &[u8]) -> Cow<str> {
-        String::from_utf8_lossy(bytes)
-    }
-
-    // The generated code calls this like:
-    //
-    //     let value = &_serde::export::from_utf8_lossy(bytes);
-    //     Err(_serde::de::Error::unknown_variant(value, VARIANTS))
-    //
-    // so it is okay for the return type to be different from the std case as long
-    // as the above works.
-    #[cfg(not(any(feature = "std", feature = "alloc")))]
-    pub fn from_utf8_lossy(bytes: &[u8]) -> &str {
-        // Three unicode replacement characters if it fails. They look like a
-        // white-on-black question mark. The user will recognize it as invalid
-        // UTF-8.
-        str::from_utf8(bytes).unwrap_or("\u{fffd}\u{fffd}\u{fffd}")
-    }
-}

serde/src/integer128.rs

@@ -10,7 +10,7 @@
 /// bother with this macro and may assume support for 128-bit integers.
 ///
 /// ```edition2018
-/// # use serde::private::ser::Error;
+/// # use serde::__private::doc::Error;
 /// #
 /// # struct MySerializer;
 /// #

serde/src/lib.rs

@@ -9,11 +9,9 @@
 //! these two groups interact with each other, allowing any supported data
 //! structure to be serialized and deserialized using any supported data format.
 //!
-//! See the Serde website [https://serde.rs/] for additional documentation and
+//! See the Serde website <https://serde.rs/> for additional documentation and
 //! usage examples.
 //!
-//! [https://serde.rs/]: https://serde.rs/
-//!
 //! ## Design
 //!
 //! Where many other languages rely on runtime reflection for serializing data,
@@ -37,8 +35,8 @@
 //!   used for IPC within the Servo rendering engine.
 //! - [CBOR], a Concise Binary Object Representation designed for small message
 //!   size without the need for version negotiation.
-//! - [YAML], a popular human-friendly configuration language that ain't markup
-//!   language.
+//! - [YAML], a self-proclaimed human-friendly configuration language that ain't
+//!   markup language.
 //! - [MessagePack], an efficient binary format that resembles a compact JSON.
 //! - [TOML], a minimal configuration format used by [Cargo].
 //! - [Pickle], a format common in the Python world.
@@ -46,16 +44,22 @@
 //! - [BSON], the data storage and network transfer format used by MongoDB.
 //! - [Avro], a binary format used within Apache Hadoop, with support for schema
 //!   definition.
-//! - [JSON5], A superset of JSON including some productions from ES5.
+//! - [JSON5], a superset of JSON including some productions from ES5.
 //! - [Postcard], a no\_std and embedded-systems friendly compact binary format.
-//! - [URL], the x-www-form-urlencoded format.
+//! - [URL] query strings, in the x-www-form-urlencoded format.
 //! - [Envy], a way to deserialize environment variables into Rust structs.
 //!   *(deserialization only)*
 //! - [Envy Store], a way to deserialize [AWS Parameter Store] parameters into
 //!   Rust structs. *(deserialization only)*
+//! - [S-expressions], the textual representation of code and data used by the
+//!   Lisp language family.
+//! - [D-Bus]'s binary wire format.
+//! - [FlexBuffers], the schemaless cousin of Google's FlatBuffers zero-copy serialization format.
+//! - [DynamoDB Items], the format used by [rusoto_dynamodb] to transfer data to
+//!   and from DynamoDB.
 //!
 //! [JSON]: https://github.com/serde-rs/json
-//! [Bincode]: https://github.com/TyOverby/bincode
+//! [Bincode]: https://github.com/servo/bincode
 //! [CBOR]: https://github.com/pyfisch/cbor
 //! [YAML]: https://github.com/dtolnay/serde-yaml
 //! [MessagePack]: https://github.com/3Hren/msgpack-rust
@@ -66,23 +70,28 @@
 //! [Avro]: https://github.com/flavray/avro-rs
 //! [JSON5]: https://github.com/callum-oakley/json5-rs
 //! [Postcard]: https://github.com/jamesmunns/postcard
-//! [URL]: https://github.com/nox/serde_urlencoded
+//! [URL]: https://docs.rs/serde_qs
 //! [Envy]: https://github.com/softprops/envy
 //! [Envy Store]: https://github.com/softprops/envy-store
 //! [Cargo]: http://doc.crates.io/manifest.html
 //! [AWS Parameter Store]: https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-paramstore.html
+//! [S-expressions]: https://github.com/rotty/lexpr-rs
+//! [D-Bus]: https://docs.rs/zvariant
+//! [FlexBuffers]: https://github.com/google/flatbuffers/tree/master/rust/flexbuffers
+//! [DynamoDB Items]: https://docs.rs/serde_dynamo
+//! [rusoto_dynamodb]: https://docs.rs/rusoto_dynamodb
 
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.108")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.125")]
 // Support using Serde without the standard library!
 #![cfg_attr(not(feature = "std"), no_std)]
 // Unstable functionality only if the user asks for it. For tracking and
 // discussion of these features please refer to this issue:
 //
 //    https://github.com/serde-rs/serde/issues/812
-#![cfg_attr(feature = "unstable", feature(specialization, never_type))]
+#![cfg_attr(feature = "unstable", feature(never_type))]
 #![allow(unknown_lints, bare_trait_objects, deprecated)]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
@@ -90,6 +99,8 @@
 #![cfg_attr(
     feature = "cargo-clippy",
     allow(
+        // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+        unnested_or_patterns,
         // not available in our oldest supported compiler
         checked_conversions,
         empty_enum,
@@ -102,12 +113,16 @@
         // things are often more readable this way
         cast_lossless,
         module_name_repetitions,
+        option_if_let_else,
         single_match_else,
         type_complexity,
         use_self,
         zero_prefixed_literal,
         // correctly used
         enum_glob_use,
+        let_underscore_drop,
+        map_err_ignore,
+        result_unit_err,
         wildcard_imports,
         // not practical
         needless_pass_by_value,
@@ -124,7 +139,6 @@
     )
 )]
 // Rustc lints.
-#![forbid(unsafe_code)]
 #![deny(missing_docs, unused_imports)]
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -154,6 +168,7 @@ mod lib {
     pub use self::core::default::{self, Default};
     pub use self::core::fmt::{self, Debug, Display};
     pub use self::core::marker::{self, PhantomData};
+    pub use self::core::num::Wrapping;
     pub use self::core::ops::Range;
     pub use self::core::option::{self, Option};
     pub use self::core::result::{self, Result};
@@ -205,8 +220,6 @@ mod lib {
     #[cfg(feature = "std")]
     pub use std::io::Write;
     #[cfg(feature = "std")]
-    pub use std::num::Wrapping;
-    #[cfg(feature = "std")]
     pub use std::path::{Path, PathBuf};
     #[cfg(feature = "std")]
     pub use std::sync::{Mutex, RwLock};
@@ -253,13 +266,18 @@ pub use de::{Deserialize, Deserializer};
 #[doc(inline)]
 pub use ser::{Serialize, Serializer};
 
-// Generated code uses these to support no_std. Not public API.
+// Used by generated code and doc tests. Not public API.
 #[doc(hidden)]
-pub mod export;
+#[path = "private/mod.rs"]
+pub mod __private;
 
-// Helpers used by generated code and doc tests. Not public API.
-#[doc(hidden)]
-pub mod private;
+#[allow(unused_imports)]
+use self::__private as export;
+#[allow(unused_imports)]
+use self::__private as private;
+
+#[path = "de/seed.rs"]
+mod seed;
 
 #[cfg(not(feature = "std"))]
 mod std_error;

serde/src/macros.rs

@@ -124,7 +124,7 @@ macro_rules! forward_to_deserialize_any {
 macro_rules! forward_to_deserialize_any_method {
     ($func:ident<$l:tt, $v:ident>($($arg:ident : $ty:ty),*)) => {
         #[inline]
-        fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::export::Result<$v::Value, Self::Error>
+        fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::__private::Result<$v::Value, Self::Error>
         where
             $v: $crate::de::Visitor<$l>,
         {

serde/src/private/de.rs

@@ -1,9 +1,10 @@
 use lib::*;
 
-use de::{Deserialize, DeserializeSeed, Deserializer, Error, IntoDeserializer, Visitor};
+use de::value::{BorrowedBytesDeserializer, BytesDeserializer};
+use de::{Deserialize, Deserializer, Error, IntoDeserializer, Visitor};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-use de::{MapAccess, Unexpected};
+use de::{DeserializeSeed, MapAccess, Unexpected};
 
 #[cfg(any(feature = "std", feature = "alloc"))]
 pub use self::content::{
@@ -12,6 +13,8 @@ pub use self::content::{
     TagOrContentField, TagOrContentFieldVisitor, TaggedContentVisitor, UntaggedUnitVisitor,
 };
 
+pub use seed::InPlaceSeed;
+
 /// If the missing field is of type `Option<T>` then treat is as `None`,
 /// otherwise it is an error.
 pub fn missing_field<'de, V, E>(field: &'static str) -> Result<V, E>
@@ -188,29 +191,6 @@ where
         .map(From::from)
 }
 
-pub mod size_hint {
-    use lib::*;
-
-    pub fn from_bounds<I>(iter: &I) -> Option<usize>
-    where
-        I: Iterator,
-    {
-        helper(iter.size_hint())
-    }
-
-    #[inline]
-    pub fn cautious(hint: Option<usize>) -> usize {
-        cmp::min(hint.unwrap_or(0), 4096)
-    }
-
-    fn helper(bounds: (usize, Option<usize>)) -> Option<usize> {
-        match bounds {
-            (lower, Some(upper)) if lower == upper => Some(upper),
-            _ => None,
-        }
-    }
-}
-
 #[cfg(any(feature = "std", feature = "alloc"))]
 mod content {
     // This module is private and nothing here should be used outside of
@@ -225,7 +205,7 @@ mod content {
 
     use lib::*;
 
-    use super::size_hint;
+    use __private::size_hint;
     use de::{
         self, Deserialize, DeserializeSeed, Deserializer, EnumAccess, Expected, IgnoredAny,
         MapAccess, SeqAccess, Unexpected, Visitor,
@@ -824,15 +804,17 @@ mod content {
     /// Not public API.
     pub struct TaggedContentVisitor<'de, T> {
         tag_name: &'static str,
+        expecting: &'static str,
         value: PhantomData<TaggedContent<'de, T>>,
     }
 
     impl<'de, T> TaggedContentVisitor<'de, T> {
         /// Visitor for the content of an internally tagged enum with the given
         /// tag name.
-        pub fn new(name: &'static str) -> Self {
+        pub fn new(name: &'static str, expecting: &'static str) -> Self {
             TaggedContentVisitor {
                 tag_name: name,
+                expecting: expecting,
                 value: PhantomData,
             }
         }
@@ -861,7 +843,7 @@ mod content {
         type Value = TaggedContent<'de, T>;
 
         fn expecting(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-            fmt.write_str("internally tagged enum")
+            fmt.write_str(self.expecting)
         }
 
         fn visit_seq<S>(self, mut seq: S) -> Result<Self::Value, S::Error>
@@ -1040,6 +1022,25 @@ mod content {
                 _ => Err(self.invalid_type(&visitor)),
             }
         }
+
+        fn deserialize_float<V>(self, visitor: V) -> Result<V::Value, E>
+        where
+            V: Visitor<'de>,
+        {
+            match self.content {
+                Content::F32(v) => visitor.visit_f32(v),
+                Content::F64(v) => visitor.visit_f64(v),
+                Content::U8(v) => visitor.visit_u8(v),
+                Content::U16(v) => visitor.visit_u16(v),
+                Content::U32(v) => visitor.visit_u32(v),
+                Content::U64(v) => visitor.visit_u64(v),
+                Content::I8(v) => visitor.visit_i8(v),
+                Content::I16(v) => visitor.visit_i16(v),
+                Content::I32(v) => visitor.visit_i32(v),
+                Content::I64(v) => visitor.visit_i64(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
     }
 
     fn visit_content_seq<'de, V, E>(content: Vec<Content<'de>>, visitor: V) -> Result<V::Value, E>
@@ -1179,25 +1180,14 @@ mod content {
         where
             V: Visitor<'de>,
         {
-            match self.content {
-                Content::F32(v) => visitor.visit_f32(v),
-                Content::F64(v) => visitor.visit_f64(v),
-                Content::U64(v) => visitor.visit_u64(v),
-                Content::I64(v) => visitor.visit_i64(v),
-                _ => Err(self.invalid_type(&visitor)),
-            }
+            self.deserialize_float(visitor)
         }
 
         fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
         where
             V: Visitor<'de>,
         {
-            match self.content {
-                Content::F64(v) => visitor.visit_f64(v),
-                Content::U64(v) => visitor.visit_u64(v),
-                Content::I64(v) => visitor.visit_i64(v),
-                _ => Err(self.invalid_type(&visitor)),
-            }
+            self.deserialize_float(visitor)
         }
 
         fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error>
@@ -1297,8 +1287,9 @@ mod content {
                 //     }
                 //
                 // We want {"topic":"Info"} to deserialize even though
-                // ordinarily unit structs do not deserialize from empty map.
+                // ordinarily unit structs do not deserialize from empty map/seq.
                 Content::Map(ref v) if v.is_empty() => visitor.visit_unit(),
+                Content::Seq(ref v) if v.is_empty() => visitor.visit_unit(),
                 _ => self.deserialize_any(visitor),
             }
         }
@@ -1562,7 +1553,7 @@ mod content {
                     other.unexpected(),
                     &"struct variant",
                 )),
-                _ => Err(de::Error::invalid_type(
+                None => Err(de::Error::invalid_type(
                     de::Unexpected::UnitVariant,
                     &"struct variant",
                 )),
@@ -1751,6 +1742,25 @@ mod content {
                 _ => Err(self.invalid_type(&visitor)),
             }
         }
+
+        fn deserialize_float<V>(self, visitor: V) -> Result<V::Value, E>
+        where
+            V: Visitor<'de>,
+        {
+            match *self.content {
+                Content::F32(v) => visitor.visit_f32(v),
+                Content::F64(v) => visitor.visit_f64(v),
+                Content::U8(v) => visitor.visit_u8(v),
+                Content::U16(v) => visitor.visit_u16(v),
+                Content::U32(v) => visitor.visit_u32(v),
+                Content::U64(v) => visitor.visit_u64(v),
+                Content::I8(v) => visitor.visit_i8(v),
+                Content::I16(v) => visitor.visit_i16(v),
+                Content::I32(v) => visitor.visit_i32(v),
+                Content::I64(v) => visitor.visit_i64(v),
+                _ => Err(self.invalid_type(&visitor)),
+            }
+        }
     }
 
     fn visit_content_seq_ref<'a, 'de, V, E>(
@@ -1898,25 +1908,14 @@ mod content {
         where
             V: Visitor<'de>,
         {
-            match *self.content {
-                Content::F32(v) => visitor.visit_f32(v),
-                Content::F64(v) => visitor.visit_f64(v),
-                Content::U64(v) => visitor.visit_u64(v),
-                Content::I64(v) => visitor.visit_i64(v),
-                _ => Err(self.invalid_type(&visitor)),
-            }
+            self.deserialize_float(visitor)
         }
 
         fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Self::Error>
         where
             V: Visitor<'de>,
         {
-            match *self.content {
-                Content::F64(v) => visitor.visit_f64(v),
-                Content::U64(v) => visitor.visit_u64(v),
-                Content::I64(v) => visitor.visit_i64(v),
-                _ => Err(self.invalid_type(&visitor)),
-            }
+            self.deserialize_float(visitor)
         }
 
         fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error>
@@ -2252,7 +2251,7 @@ mod content {
                     other.unexpected(),
                     &"struct variant",
                 )),
-                _ => Err(de::Error::invalid_type(
+                None => Err(de::Error::invalid_type(
                     de::Unexpected::UnitVariant,
                     &"struct variant",
                 )),
@@ -2542,11 +2541,13 @@ pub trait IdentifierDeserializer<'de, E: Error> {
     fn from(self) -> Self::Deserializer;
 }
 
-impl<'de, E> IdentifierDeserializer<'de, E> for u32
+pub struct Borrowed<'de, T: 'de + ?Sized>(pub &'de T);
+
+impl<'de, E> IdentifierDeserializer<'de, E> for u64
 where
     E: Error,
 {
-    type Deserializer = <u32 as IntoDeserializer<'de, E>>::Deserializer;
+    type Deserializer = <u64 as IntoDeserializer<'de, E>>::Deserializer;
 
     fn from(self) -> Self::Deserializer {
         self.into_deserializer()
@@ -2558,20 +2559,6 @@ pub struct StrDeserializer<'a, E> {
     marker: PhantomData<E>,
 }
 
-impl<'a, E> IdentifierDeserializer<'a, E> for &'a str
-where
-    E: Error,
-{
-    type Deserializer = StrDeserializer<'a, E>;
-
-    fn from(self) -> Self::Deserializer {
-        StrDeserializer {
-            value: self,
-            marker: PhantomData,
-        }
-    }
-}
-
 impl<'de, 'a, E> Deserializer<'de> for StrDeserializer<'a, E>
 where
     E: Error,
@@ -2592,26 +2579,12 @@ where
     }
 }
 
-pub struct BytesDeserializer<'a, E> {
-    value: &'a [u8],
+pub struct BorrowedStrDeserializer<'de, E> {
+    value: &'de str,
     marker: PhantomData<E>,
 }
 
-impl<'a, E> IdentifierDeserializer<'a, E> for &'a [u8]
-where
-    E: Error,
-{
-    type Deserializer = BytesDeserializer<'a, E>;
-
-    fn from(self) -> Self::Deserializer {
-        BytesDeserializer {
-            value: self,
-            marker: PhantomData,
-        }
-    }
-}
-
-impl<'de, 'a, E> Deserializer<'de> for BytesDeserializer<'a, E>
+impl<'de, E> Deserializer<'de> for BorrowedStrDeserializer<'de, E>
 where
     E: Error,
 {
@@ -2621,7 +2594,7 @@ where
     where
         V: Visitor<'de>,
     {
-        visitor.visit_bytes(self.value)
+        visitor.visit_borrowed_str(self.value)
     }
 
     forward_to_deserialize_any! {
@@ -2631,21 +2604,53 @@ where
     }
 }
 
-/// A DeserializeSeed helper for implementing deserialize_in_place Visitors.
-///
-/// Wraps a mutable reference and calls deserialize_in_place on it.
-pub struct InPlaceSeed<'a, T: 'a>(pub &'a mut T);
-
-impl<'a, 'de, T> DeserializeSeed<'de> for InPlaceSeed<'a, T>
+impl<'a, E> IdentifierDeserializer<'a, E> for &'a str
 where
-    T: Deserialize<'de>,
+    E: Error,
 {
-    type Value = ();
-    fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        T::deserialize_in_place(deserializer, self.0)
+    type Deserializer = StrDeserializer<'a, E>;
+
+    fn from(self) -> Self::Deserializer {
+        StrDeserializer {
+            value: self,
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<'de, E> IdentifierDeserializer<'de, E> for Borrowed<'de, str>
+where
+    E: Error,
+{
+    type Deserializer = BorrowedStrDeserializer<'de, E>;
+
+    fn from(self) -> Self::Deserializer {
+        BorrowedStrDeserializer {
+            value: self.0,
+            marker: PhantomData,
+        }
+    }
+}
+
+impl<'a, E> IdentifierDeserializer<'a, E> for &'a [u8]
+where
+    E: Error,
+{
+    type Deserializer = BytesDeserializer<'a, E>;
+
+    fn from(self) -> Self::Deserializer {
+        BytesDeserializer::new(self)
+    }
+}
+
+impl<'de, E> IdentifierDeserializer<'de, E> for Borrowed<'de, [u8]>
+where
+    E: Error,
+{
+    type Deserializer = BorrowedBytesDeserializer<'de, E>;
+
+    fn from(self) -> Self::Deserializer {
+        BorrowedBytesDeserializer::new(self.0)
     }
 }
 
@@ -2763,6 +2768,13 @@ where
         }
     }
 
+    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: Visitor<'de>,
+    {
+        visitor.visit_unit()
+    }
+
     forward_to_deserialize_other! {
         deserialize_bool()
         deserialize_i8()
@@ -2780,7 +2792,6 @@ where
         deserialize_string()
         deserialize_bytes()
         deserialize_byte_buf()
-        deserialize_unit()
         deserialize_unit_struct(&'static str)
         deserialize_seq()
         deserialize_tuple(usize)

serde/src/private/doc.rs

@@ -1,3 +1,35 @@
+// Used only by Serde doc tests. Not public API.
+
+use lib::*;
+
+use ser;
+
+#[doc(hidden)]
+#[derive(Debug)]
+pub struct Error;
+
+impl ser::Error for Error {
+    fn custom<T>(_: T) -> Self
+    where
+        T: Display,
+    {
+        unimplemented!()
+    }
+}
+
+#[cfg(feature = "std")]
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        unimplemented!()
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
+        unimplemented!()
+    }
+}
+
 #[doc(hidden)]
 #[macro_export]
 macro_rules! __private_serialize {
@@ -10,19 +42,6 @@ macro_rules! __private_serialize {
     };
 }
 
-#[doc(hidden)]
-#[macro_export]
-macro_rules! __private_deserialize {
-    () => {
-        trait Deserialize<'de>: Sized {
-            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-            where
-                D: $crate::Deserializer<'de>;
-        }
-    };
-}
-
-/// Used only by Serde doc tests. Not public API.
 #[doc(hidden)]
 #[macro_export(local_inner_macros)]
 macro_rules! __serialize_unimplemented {
@@ -37,7 +56,7 @@ macro_rules! __serialize_unimplemented {
 #[macro_export]
 macro_rules! __serialize_unimplemented_method {
     ($func:ident $(<$t:ident>)* ($($arg:ty),*) -> $ret:ident) => {
-        fn $func $(<$t: ?Sized + $crate::Serialize>)* (self $(, _: $arg)*) -> $crate::export::Result<Self::$ret, Self::Error> {
+        fn $func $(<$t: ?Sized + $crate::Serialize>)* (self $(, _: $arg)*) -> $crate::__private::Result<Self::$ret, Self::Error> {
             unimplemented!()
         }
     };

serde/src/private/mod.rs

@@ -1,4 +1,49 @@
-mod macros;
-
+#[cfg(serde_derive)]
 pub mod de;
+#[cfg(serde_derive)]
 pub mod ser;
+
+pub mod size_hint;
+
+// FIXME: #[cfg(doctest)] once https://github.com/rust-lang/rust/issues/67295 is fixed.
+pub mod doc;
+
+pub use lib::clone::Clone;
+pub use lib::convert::{From, Into};
+pub use lib::default::Default;
+pub use lib::fmt::{self, Formatter};
+pub use lib::marker::PhantomData;
+pub use lib::option::Option::{self, None, Some};
+pub use lib::result::Result::{self, Err, Ok};
+
+pub use self::string::from_utf8_lossy;
+
+#[cfg(any(feature = "alloc", feature = "std"))]
+pub use lib::{ToString, Vec};
+
+#[cfg(core_try_from)]
+pub use lib::convert::TryFrom;
+
+mod string {
+    use lib::*;
+
+    #[cfg(any(feature = "std", feature = "alloc"))]
+    pub fn from_utf8_lossy(bytes: &[u8]) -> Cow<str> {
+        String::from_utf8_lossy(bytes)
+    }
+
+    // The generated code calls this like:
+    //
+    //     let value = &_serde::__private::from_utf8_lossy(bytes);
+    //     Err(_serde::de::Error::unknown_variant(value, VARIANTS))
+    //
+    // so it is okay for the return type to be different from the std case as long
+    // as the above works.
+    #[cfg(not(any(feature = "std", feature = "alloc")))]
+    pub fn from_utf8_lossy(bytes: &[u8]) -> &str {
+        // Three unicode replacement characters if it fails. They look like a
+        // white-on-black question mark. The user will recognize it as invalid
+        // UTF-8.
+        str::from_utf8(bytes).unwrap_or("\u{fffd}\u{fffd}\u{fffd}")
+    }
+}

serde/src/private/ser.rs

@@ -335,33 +335,6 @@ where
     }
 }
 
-/// Used only by Serde doc tests. Not public API.
-#[doc(hidden)]
-#[derive(Debug)]
-pub struct Error;
-
-impl ser::Error for Error {
-    fn custom<T>(_: T) -> Self
-    where
-        T: Display,
-    {
-        unimplemented!()
-    }
-}
-
-#[cfg(feature = "std")]
-impl error::Error for Error {
-    fn description(&self) -> &str {
-        unimplemented!()
-    }
-}
-
-impl Display for Error {
-    fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
-        unimplemented!()
-    }
-}
-
 #[cfg(any(feature = "std", feature = "alloc"))]
 mod content {
     use lib::*;
@@ -452,7 +425,6 @@ mod content {
         }
     }
 
-    #[derive(Debug)]
     pub enum Content {
         Bool(bool),
 
@@ -1124,7 +1096,7 @@ where
     }
 
     fn serialize_unit(self) -> Result<Self::Ok, Self::Error> {
-        Err(Self::bad_type(Unsupported::Unit))
+        Ok(())
     }
 
     fn serialize_unit_struct(self, _: &'static str) -> Result<Self::Ok, Self::Error> {
@@ -1243,6 +1215,18 @@ where
         self.0.serialize_value(value)
     }
 
+    fn serialize_entry<K: ?Sized, V: ?Sized>(
+        &mut self,
+        key: &K,
+        value: &V,
+    ) -> Result<(), Self::Error>
+    where
+        K: Serialize,
+        V: Serialize,
+    {
+        self.0.serialize_entry(key, value)
+    }
+
     fn end(self) -> Result<(), Self::Error> {
         Ok(())
     }

serde/src/private/size_hint.rs

@@ -0,0 +1,21 @@
+use lib::*;
+
+pub fn from_bounds<I>(iter: &I) -> Option<usize>
+where
+    I: Iterator,
+{
+    helper(iter.size_hint())
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+#[inline]
+pub fn cautious(hint: Option<usize>) -> usize {
+    cmp::min(hint.unwrap_or(0), 4096)
+}
+
+fn helper(bounds: (usize, Option<usize>)) -> Option<usize> {
+    match bounds {
+        (lower, Some(upper)) if lower == upper => Some(upper),
+        _ => None,
+    }
+}

serde/src/ser/impls.rs

@@ -616,7 +616,7 @@ impl Serialize for SystemTime {
         use super::SerializeStruct;
         let duration_since_epoch = self
             .duration_since(UNIX_EPOCH)
-            .expect("SystemTime must be later than UNIX_EPOCH");
+            .map_err(|_| S::Error::custom("SystemTime must be later than UNIX_EPOCH"))?;
         let mut state = try!(serializer.serialize_struct("SystemTime", 2));
         try!(state.serialize_field("secs_since_epoch", &duration_since_epoch.as_secs()));
         try!(state.serialize_field("nanos_since_epoch", &duration_since_epoch.subsec_nanos()));
@@ -674,6 +674,52 @@ impl Serialize for net::IpAddr {
     }
 }
 
+#[cfg(feature = "std")]
+const DEC_DIGITS_LUT: &'static [u8] = b"\
+      0001020304050607080910111213141516171819\
+      2021222324252627282930313233343536373839\
+      4041424344454647484950515253545556575859\
+      6061626364656667686970717273747576777879\
+      8081828384858687888990919293949596979899";
+
+#[cfg(feature = "std")]
+#[inline]
+fn format_u8(mut n: u8, out: &mut [u8]) -> usize {
+    if n >= 100 {
+        let d1 = ((n % 100) << 1) as usize;
+        n /= 100;
+        out[0] = b'0' + n;
+        out[1] = DEC_DIGITS_LUT[d1];
+        out[2] = DEC_DIGITS_LUT[d1 + 1];
+        3
+    } else if n >= 10 {
+        let d1 = (n << 1) as usize;
+        out[0] = DEC_DIGITS_LUT[d1];
+        out[1] = DEC_DIGITS_LUT[d1 + 1];
+        2
+    } else {
+        out[0] = b'0' + n;
+        1
+    }
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn test_format_u8() {
+    let mut i = 0u8;
+
+    loop {
+        let mut buf = [0u8; 3];
+        let written = format_u8(i, &mut buf);
+        assert_eq!(i.to_string().as_bytes(), &buf[..written]);
+
+        match i.checked_add(1) {
+            Some(next) => i = next,
+            None => break,
+        }
+    }
+}
+
 #[cfg(feature = "std")]
 impl Serialize for net::Ipv4Addr {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
@@ -683,7 +729,14 @@ impl Serialize for net::Ipv4Addr {
         if serializer.is_human_readable() {
             const MAX_LEN: usize = 15;
             debug_assert_eq!(MAX_LEN, "101.102.103.104".len());
-            serialize_display_bounded_length!(self, MAX_LEN, serializer)
+            let mut buf = [b'.'; MAX_LEN];
+            let mut written = format_u8(self.octets()[0], &mut buf);
+            for oct in &self.octets()[1..] {
+                // Skip over delimiters that we initialized buf with
+                written += format_u8(*oct, &mut buf[written + 1..]) + 1;
+            }
+            // We've only written ASCII bytes to the buffer, so it is valid UTF-8
+            serializer.serialize_str(unsafe { str::from_utf8_unchecked(&buf[..written]) })
         } else {
             self.octets().serialize(serializer)
         }
@@ -753,10 +806,10 @@ impl Serialize for net::SocketAddrV6 {
         S: Serializer,
     {
         if serializer.is_human_readable() {
-            const MAX_LEN: usize = 47;
+            const MAX_LEN: usize = 58;
             debug_assert_eq!(
                 MAX_LEN,
-                "[1001:1002:1003:1004:1005:1006:1007:1008]:65000".len()
+                "[1001:1002:1003:1004:1005:1006:1007:1008%4294967295]:65000".len()
             );
             serialize_display_bounded_length!(self, MAX_LEN, serializer)
         } else {
@@ -824,7 +877,6 @@ impl Serialize for OsString {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(feature = "std")]
 impl<T> Serialize for Wrapping<T>
 where
     T: Serialize,

serde/src/ser/impossible.rs

@@ -17,7 +17,7 @@ use ser::{
 ///
 /// ```edition2018
 /// # use serde::ser::{Serializer, Impossible};
-/// # use serde::private::ser::Error;
+/// # use serde::__private::doc::Error;
 /// #
 /// # struct MySerializer;
 /// #

serde/src/ser/mod.rs

@@ -99,7 +99,7 @@
 //! [`LinkedHashMap<K, V>`]: https://docs.rs/linked-hash-map/*/linked_hash_map/struct.LinkedHashMap.html
 //! [`Serialize`]: ../trait.Serialize.html
 //! [`Serializer`]: ../trait.Serializer.html
-//! [`bincode`]: https://github.com/TyOverby/bincode
+//! [`bincode`]: https://github.com/servo/bincode
 //! [`linked-hash-map`]: https://crates.io/crates/linked-hash-map
 //! [`serde_derive`]: https://crates.io/crates/serde_derive
 //! [`serde_json`]: https://github.com/serde-rs/json
@@ -711,7 +711,7 @@ pub trait Serializer: Sized {
     ///
     /// ```edition2018
     /// # use serde::ser::{Serializer, SerializeSeq};
-    /// # use serde::private::ser::Error;
+    /// # use serde::__private::doc::Error;
     /// #
     /// # struct MySerializer;
     /// #
@@ -1278,7 +1278,7 @@ pub trait Serializer: Sized {
         <I as IntoIterator>::Item: Serialize,
     {
         let iter = iter.into_iter();
-        let mut serializer = try!(self.serialize_seq(iter.len_hint()));
+        let mut serializer = try!(self.serialize_seq(iterator_len_hint(&iter)));
         for item in iter {
             try!(serializer.serialize_element(&item));
         }
@@ -1318,7 +1318,7 @@ pub trait Serializer: Sized {
         I: IntoIterator<Item = (K, V)>,
     {
         let iter = iter.into_iter();
-        let mut serializer = try!(self.serialize_map(iter.len_hint()));
+        let mut serializer = try!(self.serialize_map(iterator_len_hint(&iter)));
         for (key, value) in iter {
             try!(serializer.serialize_entry(&key, &value));
         }
@@ -1953,35 +1953,6 @@ pub trait SerializeStructVariant {
     fn end(self) -> Result<Self::Ok, Self::Error>;
 }
 
-trait LenHint: Iterator {
-    fn len_hint(&self) -> Option<usize>;
-}
-
-impl<I> LenHint for I
-where
-    I: Iterator,
-{
-    #[cfg(not(feature = "unstable"))]
-    fn len_hint(&self) -> Option<usize> {
-        iterator_len_hint(self)
-    }
-
-    #[cfg(feature = "unstable")]
-    default fn len_hint(&self) -> Option<usize> {
-        iterator_len_hint(self)
-    }
-}
-
-#[cfg(feature = "unstable")]
-impl<I> LenHint for I
-where
-    I: ExactSizeIterator,
-{
-    fn len_hint(&self) -> Option<usize> {
-        Some(self.len())
-    }
-}
-
 fn iterator_len_hint<I>(iter: &I) -> Option<usize>
 where
     I: Iterator,

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.108" # remember to update html_root_url
+version = "1.0.125" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT OR Apache-2.0"
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"
@@ -9,7 +9,7 @@ repository = "https://github.com/serde-rs/serde"
 documentation = "https://serde.rs/derive.html"
 keywords = ["serde", "serialization", "no_std"]
 readme = "crates-io.md"
-include = ["Cargo.toml", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
+include = ["build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
 
 [features]
 default = []
@@ -22,7 +22,7 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "1.0", features = ["visit"] }
+syn = "1.0.60"
 
 [dev-dependencies]
 serde = { version = "1.0", path = "../serde" }

serde_derive/build.rs

@@ -0,0 +1,30 @@
+use std::env;
+use std::process::Command;
+use std::str;
+
+// The rustc-cfg strings below are *not* public API. Please let us know by
+// opening a GitHub issue if your build environment requires some way to enable
+// these cfgs other than by executing our build script.
+fn main() {
+    let minor = match rustc_minor_version() {
+        Some(minor) => minor,
+        None => return,
+    };
+
+    // Underscore const names stabilized in Rust 1.37:
+    // https://blog.rust-lang.org/2019/08/15/Rust-1.37.0.html#using-unnamed-const-items-for-macros
+    if minor >= 37 {
+        println!("cargo:rustc-cfg=underscore_consts");
+    }
+}
+
+fn rustc_minor_version() -> Option<u32> {
+    let rustc = env::var_os("RUSTC")?;
+    let output = Command::new(rustc).arg("--version").output().ok()?;
+    let version = str::from_utf8(&output.stdout).ok()?;
+    let mut pieces = version.split('.');
+    if pieces.next() != Some("rustc 1") {
+        return None;
+    }
+    pieces.next()?.parse().ok()
+}

serde_derive/src/bound.rs

@@ -2,10 +2,9 @@ use std::collections::HashSet;
 
 use syn;
 use syn::punctuated::{Pair, Punctuated};
-use syn::visit::{self, Visit};
 
 use internals::ast::{Container, Data};
-use internals::attr;
+use internals::{attr, ungroup};
 
 use proc_macro2::Span;
 
@@ -112,9 +111,10 @@ pub fn with_bound(
         // parameters.
         associated_type_usage: Vec<&'ast syn::TypePath>,
     }
-    impl<'ast> Visit<'ast> for FindTyParams<'ast> {
+
+    impl<'ast> FindTyParams<'ast> {
         fn visit_field(&mut self, field: &'ast syn::Field) {
-            if let syn::Type::Path(ty) = &field.ty {
+            if let syn::Type::Path(ty) = ungroup(&field.ty) {
                 if let Some(Pair::Punctuated(t, _)) = ty.path.segments.pairs().next() {
                     if self.all_type_params.contains(&t.ident) {
                         self.associated_type_usage.push(ty);
@@ -138,7 +138,98 @@ pub fn with_bound(
                     self.relevant_type_params.insert(id.clone());
                 }
             }
-            visit::visit_path(self, path);
+            for segment in &path.segments {
+                self.visit_path_segment(segment);
+            }
+        }
+
+        // Everything below is simply traversing the syntax tree.
+
+        fn visit_type(&mut self, ty: &'ast syn::Type) {
+            match ty {
+                syn::Type::Array(ty) => self.visit_type(&ty.elem),
+                syn::Type::BareFn(ty) => {
+                    for arg in &ty.inputs {
+                        self.visit_type(&arg.ty);
+                    }
+                    self.visit_return_type(&ty.output);
+                }
+                syn::Type::Group(ty) => self.visit_type(&ty.elem),
+                syn::Type::ImplTrait(ty) => {
+                    for bound in &ty.bounds {
+                        self.visit_type_param_bound(bound);
+                    }
+                }
+                syn::Type::Macro(ty) => self.visit_macro(&ty.mac),
+                syn::Type::Paren(ty) => self.visit_type(&ty.elem),
+                syn::Type::Path(ty) => {
+                    if let Some(qself) = &ty.qself {
+                        self.visit_type(&qself.ty);
+                    }
+                    self.visit_path(&ty.path);
+                }
+                syn::Type::Ptr(ty) => self.visit_type(&ty.elem),
+                syn::Type::Reference(ty) => self.visit_type(&ty.elem),
+                syn::Type::Slice(ty) => self.visit_type(&ty.elem),
+                syn::Type::TraitObject(ty) => {
+                    for bound in &ty.bounds {
+                        self.visit_type_param_bound(bound);
+                    }
+                }
+                syn::Type::Tuple(ty) => {
+                    for elem in &ty.elems {
+                        self.visit_type(elem);
+                    }
+                }
+
+                syn::Type::Infer(_) | syn::Type::Never(_) | syn::Type::Verbatim(_) => {}
+
+                #[cfg(test)]
+                syn::Type::__TestExhaustive(_) => unimplemented!(),
+                #[cfg(not(test))]
+                _ => {}
+            }
+        }
+
+        fn visit_path_segment(&mut self, segment: &'ast syn::PathSegment) {
+            self.visit_path_arguments(&segment.arguments);
+        }
+
+        fn visit_path_arguments(&mut self, arguments: &'ast syn::PathArguments) {
+            match arguments {
+                syn::PathArguments::None => {}
+                syn::PathArguments::AngleBracketed(arguments) => {
+                    for arg in &arguments.args {
+                        match arg {
+                            syn::GenericArgument::Type(arg) => self.visit_type(arg),
+                            syn::GenericArgument::Binding(arg) => self.visit_type(&arg.ty),
+                            syn::GenericArgument::Lifetime(_)
+                            | syn::GenericArgument::Constraint(_)
+                            | syn::GenericArgument::Const(_) => {}
+                        }
+                    }
+                }
+                syn::PathArguments::Parenthesized(arguments) => {
+                    for argument in &arguments.inputs {
+                        self.visit_type(argument);
+                    }
+                    self.visit_return_type(&arguments.output);
+                }
+            }
+        }
+
+        fn visit_return_type(&mut self, return_type: &'ast syn::ReturnType) {
+            match return_type {
+                syn::ReturnType::Default => {}
+                syn::ReturnType::Type(_, output) => self.visit_type(output),
+            }
+        }
+
+        fn visit_type_param_bound(&mut self, bound: &'ast syn::TypeParamBound) {
+            match bound {
+                syn::TypeParamBound::Trait(bound) => self.visit_path(&bound.path),
+                syn::TypeParamBound::Lifetime(_) => {}
+            }
         }
 
         // Type parameter should not be considered used by a macro path.

serde_derive/src/dummy.rs

@@ -1,4 +1,5 @@
-use proc_macro2::{Ident, Span, TokenStream};
+use proc_macro2::{Ident, TokenStream};
+use quote::format_ident;
 
 use syn;
 use try;
@@ -11,10 +12,11 @@ pub fn wrap_in_const(
 ) -> TokenStream {
     let try_replacement = try::replacement();
 
-    let dummy_const = Ident::new(
-        &format!("_IMPL_{}_FOR_{}", trait_, unraw(ty)),
-        Span::call_site(),
-    );
+    let dummy_const = if cfg!(underscore_consts) {
+        format_ident!("_")
+    } else {
+        format_ident!("_IMPL_{}_FOR_{}", trait_, unraw(ty))
+    };
 
     let use_serde = match serde_path {
         Some(path) => quote! {

serde_derive/src/internals/attr.rs

@@ -1,10 +1,10 @@
+use internals::respan::respan;
 use internals::symbol::*;
-use internals::Ctxt;
-use proc_macro2::{Group, Span, TokenStream, TokenTree};
+use internals::{ungroup, Ctxt};
+use proc_macro2::{Spacing, Span, TokenStream, TokenTree};
 use quote::ToTokens;
 use std::borrow::Cow;
 use std::collections::BTreeSet;
-use std::str::FromStr;
 use syn;
 use syn::parse::{self, Parse, ParseStream};
 use syn::punctuated::Punctuated;
@@ -222,6 +222,9 @@ pub struct Container {
     identifier: Identifier,
     has_flatten: bool,
     serde_path: Option<syn::Path>,
+    is_packed: bool,
+    /// Error message generated when type can't be deserialized
+    expecting: Option<String>,
 }
 
 /// Styles of representing an enum.
@@ -304,6 +307,7 @@ impl Container {
         let mut field_identifier = BoolAttr::none(cx, FIELD_IDENTIFIER);
         let mut variant_identifier = BoolAttr::none(cx, VARIANT_IDENTIFIER);
         let mut serde_path = Attr::none(cx, CRATE);
+        let mut expecting = Attr::none(cx, EXPECTING);
 
         for meta_item in item
             .attrs
@@ -336,13 +340,7 @@ impl Container {
                                 rename_all_ser_rule.set(&m.path, rename_rule);
                                 rename_all_de_rule.set(&m.path, rename_rule);
                             }
-                            Err(()) => cx.error_spanned_by(
-                                s,
-                                format!(
-                                    "unknown rename rule for #[serde(rename_all = {:?})]",
-                                    s.value(),
-                                ),
-                            ),
+                            Err(err) => cx.error_spanned_by(s, err),
                         }
                     }
                 }
@@ -353,25 +351,13 @@ impl Container {
                         if let Some(ser) = ser {
                             match RenameRule::from_str(&ser.value()) {
                                 Ok(rename_rule) => rename_all_ser_rule.set(&m.path, rename_rule),
-                                Err(()) => cx.error_spanned_by(
-                                    ser,
-                                    format!(
-                                        "unknown rename rule for #[serde(rename_all = {:?})]",
-                                        ser.value(),
-                                    ),
-                                ),
+                                Err(err) => cx.error_spanned_by(ser, err),
                             }
                         }
                         if let Some(de) = de {
                             match RenameRule::from_str(&de.value()) {
                                 Ok(rename_rule) => rename_all_de_rule.set(&m.path, rename_rule),
-                                Err(()) => cx.error_spanned_by(
-                                    de,
-                                    format!(
-                                        "unknown rename rule for #[serde(rename_all = {:?})]",
-                                        de.value(),
-                                    ),
-                                ),
+                                Err(err) => cx.error_spanned_by(de, err),
                             }
                         }
                     }
@@ -574,6 +560,13 @@ impl Container {
                     }
                 }
 
+                // Parse `#[serde(expecting = "a message")]`
+                Meta(NameValue(m)) if m.path == EXPECTING => {
+                    if let Ok(s) = get_lit_str(cx, EXPECTING, &m.lit) {
+                        expecting.set(&m.path, s.value());
+                    }
+                }
+
                 Meta(meta_item) => {
                     let path = meta_item
                         .path()
@@ -592,6 +585,20 @@ impl Container {
             }
         }
 
+        let mut is_packed = false;
+        for attr in &item.attrs {
+            if attr.path.is_ident("repr") {
+                let _ = attr.parse_args_with(|input: ParseStream| {
+                    while let Some(token) = input.parse()? {
+                        if let TokenTree::Ident(ident) = token {
+                            is_packed |= ident == "packed";
+                        }
+                    }
+                    Ok(())
+                });
+            }
+        }
+
         Container {
             name: Name::from_attrs(unraw(&item.ident), ser_name, de_name, None),
             transparent: transparent.get(),
@@ -611,6 +618,8 @@ impl Container {
             identifier: decide_identifier(cx, item, field_identifier, variant_identifier),
             has_flatten: false,
             serde_path: serde_path.get(),
+            is_packed,
+            expecting: expecting.get(),
         }
     }
 
@@ -662,6 +671,10 @@ impl Container {
         self.remote.as_ref()
     }
 
+    pub fn is_packed(&self) -> bool {
+        self.is_packed
+    }
+
     pub fn identifier(&self) -> Identifier {
         self.identifier
     }
@@ -682,6 +695,12 @@ impl Container {
         self.custom_serde_path()
             .map_or_else(|| Cow::Owned(parse_quote!(_serde)), Cow::Borrowed)
     }
+
+    /// Error message generated when type can't be deserialized.
+    /// If `None`, default message will be used
+    pub fn expecting(&self) -> Option<&str> {
+        self.expecting.as_ref().map(String::as_ref)
+    }
 }
 
 fn decide_tag(
@@ -894,13 +913,7 @@ impl Variant {
                                 rename_all_ser_rule.set(&m.path, rename_rule);
                                 rename_all_de_rule.set(&m.path, rename_rule);
                             }
-                            Err(()) => cx.error_spanned_by(
-                                s,
-                                format!(
-                                    "unknown rename rule for #[serde(rename_all = {:?})]",
-                                    s.value()
-                                ),
-                            ),
+                            Err(err) => cx.error_spanned_by(s, err),
                         }
                     }
                 }
@@ -911,25 +924,13 @@ impl Variant {
                         if let Some(ser) = ser {
                             match RenameRule::from_str(&ser.value()) {
                                 Ok(rename_rule) => rename_all_ser_rule.set(&m.path, rename_rule),
-                                Err(()) => cx.error_spanned_by(
-                                    ser,
-                                    format!(
-                                        "unknown rename rule for #[serde(rename_all = {:?})]",
-                                        ser.value(),
-                                    ),
-                                ),
+                                Err(err) => cx.error_spanned_by(ser, err),
                             }
                         }
                         if let Some(de) = de {
                             match RenameRule::from_str(&de.value()) {
                                 Ok(rename_rule) => rename_all_de_rule.set(&m.path, rename_rule),
-                                Err(()) => cx.error_spanned_by(
-                                    de,
-                                    format!(
-                                        "unknown rename rule for #[serde(rename_all = {:?})]",
-                                        de.value(),
-                                    ),
-                                ),
+                                Err(err) => cx.error_spanned_by(de, err),
                             }
                         }
                     }
@@ -1373,7 +1374,7 @@ impl Field {
                 };
                 let span = Span::call_site();
                 path.segments.push(Ident::new("_serde", span).into());
-                path.segments.push(Ident::new("private", span).into());
+                path.segments.push(Ident::new("__private", span).into());
                 path.segments.push(Ident::new("de", span).into());
                 path.segments
                     .push(Ident::new("borrow_cow_str", span).into());
@@ -1390,7 +1391,7 @@ impl Field {
                 };
                 let span = Span::call_site();
                 path.segments.push(Ident::new("_serde", span).into());
-                path.segments.push(Ident::new("private", span).into());
+                path.segments.push(Ident::new("__private", span).into());
                 path.segments.push(Ident::new("de", span).into());
                 path.segments
                     .push(Ident::new("borrow_cow_bytes", span).into());
@@ -1721,7 +1722,7 @@ fn is_implicitly_borrowed_reference(ty: &syn::Type) -> bool {
 //         cow: Cow<'a, str>,
 //     }
 fn is_cow(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool {
-    let path = match ty {
+    let path = match ungroup(ty) {
         syn::Type::Path(ty) => &ty.path,
         _ => {
             return false;
@@ -1748,7 +1749,7 @@ fn is_cow(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool {
 }
 
 fn is_option(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool {
-    let path = match ty {
+    let path = match ungroup(ty) {
         syn::Type::Path(ty) => &ty.path,
         _ => {
             return false;
@@ -1795,7 +1796,7 @@ fn is_option(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool {
 //         r: &'a str,
 //     }
 fn is_reference(ty: &syn::Type, elem: fn(&syn::Type) -> bool) -> bool {
-    match ty {
+    match ungroup(ty) {
         syn::Type::Reference(ty) => ty.mutability.is_none() && elem(&ty.elem),
         _ => false,
     }
@@ -1806,14 +1807,14 @@ fn is_str(ty: &syn::Type) -> bool {
 }
 
 fn is_slice_u8(ty: &syn::Type) -> bool {
-    match ty {
+    match ungroup(ty) {
         syn::Type::Slice(ty) => is_primitive_type(&ty.elem, "u8"),
         _ => false,
     }
 }
 
 fn is_primitive_type(ty: &syn::Type, primitive: &str) -> bool {
-    match ty {
+    match ungroup(ty) {
         syn::Type::Path(ty) => ty.qself.is_none() && is_primitive_path(&ty.path, primitive),
         _ => false,
     }
@@ -1901,14 +1902,41 @@ fn collect_lifetimes(ty: &syn::Type, out: &mut BTreeSet<syn::Lifetime>) {
         syn::Type::Group(ty) => {
             collect_lifetimes(&ty.elem, out);
         }
+        syn::Type::Macro(ty) => {
+            collect_lifetimes_from_tokens(ty.mac.tokens.clone(), out);
+        }
         syn::Type::BareFn(_)
         | syn::Type::Never(_)
         | syn::Type::TraitObject(_)
         | syn::Type::ImplTrait(_)
         | syn::Type::Infer(_)
-        | syn::Type::Macro(_)
-        | syn::Type::Verbatim(_)
-        | _ => {}
+        | syn::Type::Verbatim(_) => {}
+
+        #[cfg(test)]
+        syn::Type::__TestExhaustive(_) => unimplemented!(),
+        #[cfg(not(test))]
+        _ => {}
+    }
+}
+
+fn collect_lifetimes_from_tokens(tokens: TokenStream, out: &mut BTreeSet<syn::Lifetime>) {
+    let mut iter = tokens.into_iter();
+    while let Some(tt) = iter.next() {
+        match &tt {
+            TokenTree::Punct(op) if op.as_char() == '\'' && op.spacing() == Spacing::Joint => {
+                if let Some(TokenTree::Ident(ident)) = iter.next() {
+                    out.insert(syn::Lifetime {
+                        apostrophe: op.span(),
+                        ident,
+                    });
+                }
+            }
+            TokenTree::Group(group) => {
+                let tokens = group.stream();
+                collect_lifetimes_from_tokens(tokens, out);
+            }
+            _ => {}
+        }
     }
 }
 
@@ -1922,20 +1950,5 @@ where
 
 fn spanned_tokens(s: &syn::LitStr) -> parse::Result<TokenStream> {
     let stream = syn::parse_str(&s.value())?;
-    Ok(respan_token_stream(stream, s.span()))
-}
-
-fn respan_token_stream(stream: TokenStream, span: Span) -> TokenStream {
-    stream
-        .into_iter()
-        .map(|token| respan_token_tree(token, span))
-        .collect()
-}
-
-fn respan_token_tree(mut token: TokenTree, span: Span) -> TokenTree {
-    if let TokenTree::Group(g) = &mut token {
-        *g = Group::new(g.delimiter(), respan_token_stream(g.stream(), span));
-    }
-    token.set_span(span);
-    token
+    Ok(respan(stream, s.span()))
 }

serde_derive/src/internals/case.rs

@@ -5,7 +5,7 @@
 #[allow(deprecated, unused_imports)]
 use std::ascii::AsciiExt;
 
-use std::str::FromStr;
+use std::fmt::{self, Debug, Display};
 
 use self::RenameRule::*;
 
@@ -17,7 +17,7 @@ pub enum RenameRule {
     /// Rename direct children to "lowercase" style.
     LowerCase,
     /// Rename direct children to "UPPERCASE" style.
-    UPPERCASE,
+    UpperCase,
     /// Rename direct children to "PascalCase" style, as typically used for
     /// enum variants.
     PascalCase,
@@ -35,13 +35,35 @@ pub enum RenameRule {
     ScreamingKebabCase,
 }
 
+static RENAME_RULES: &[(&str, RenameRule)] = &[
+    ("lowercase", LowerCase),
+    ("UPPERCASE", UpperCase),
+    ("PascalCase", PascalCase),
+    ("camelCase", CamelCase),
+    ("snake_case", SnakeCase),
+    ("SCREAMING_SNAKE_CASE", ScreamingSnakeCase),
+    ("kebab-case", KebabCase),
+    ("SCREAMING-KEBAB-CASE", ScreamingKebabCase),
+];
+
 impl RenameRule {
+    pub fn from_str(rename_all_str: &str) -> Result<Self, ParseError> {
+        for (name, rule) in RENAME_RULES {
+            if rename_all_str == *name {
+                return Ok(*rule);
+            }
+        }
+        Err(ParseError {
+            unknown: rename_all_str,
+        })
+    }
+
     /// Apply a renaming rule to an enum variant, returning the version expected in the source.
     pub fn apply_to_variant(&self, variant: &str) -> String {
         match *self {
             None | PascalCase => variant.to_owned(),
             LowerCase => variant.to_ascii_lowercase(),
-            UPPERCASE => variant.to_ascii_uppercase(),
+            UpperCase => variant.to_ascii_uppercase(),
             CamelCase => variant[..1].to_ascii_lowercase() + &variant[1..],
             SnakeCase => {
                 let mut snake = String::new();
@@ -65,7 +87,7 @@ impl RenameRule {
     pub fn apply_to_field(&self, field: &str) -> String {
         match *self {
             None | LowerCase | SnakeCase => field.to_owned(),
-            UPPERCASE => field.to_ascii_uppercase(),
+            UpperCase => field.to_ascii_uppercase(),
             PascalCase => {
                 let mut pascal = String::new();
                 let mut capitalize = true;
@@ -92,21 +114,22 @@ impl RenameRule {
     }
 }
 
-impl FromStr for RenameRule {
-    type Err = ();
+pub struct ParseError<'a> {
+    unknown: &'a str,
+}
 
-    fn from_str(rename_all_str: &str) -> Result<Self, Self::Err> {
-        match rename_all_str {
-            "lowercase" => Ok(LowerCase),
-            "UPPERCASE" => Ok(UPPERCASE),
-            "PascalCase" => Ok(PascalCase),
-            "camelCase" => Ok(CamelCase),
-            "snake_case" => Ok(SnakeCase),
-            "SCREAMING_SNAKE_CASE" => Ok(ScreamingSnakeCase),
-            "kebab-case" => Ok(KebabCase),
-            "SCREAMING-KEBAB-CASE" => Ok(ScreamingKebabCase),
-            _ => Err(()),
+impl<'a> Display for ParseError<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str("unknown rename rule `rename_all = ")?;
+        Debug::fmt(self.unknown, f)?;
+        f.write_str("`, expected one of ")?;
+        for (i, (name, _rule)) in RENAME_RULES.iter().enumerate() {
+            if i > 0 {
+                f.write_str(", ")?;
+            }
+            Debug::fmt(name, f)?;
         }
+        Ok(())
     }
 }
 
@@ -131,7 +154,7 @@ fn rename_variants() {
     ] {
         assert_eq!(None.apply_to_variant(original), original);
         assert_eq!(LowerCase.apply_to_variant(original), lower);
-        assert_eq!(UPPERCASE.apply_to_variant(original), upper);
+        assert_eq!(UpperCase.apply_to_variant(original), upper);
         assert_eq!(PascalCase.apply_to_variant(original), original);
         assert_eq!(CamelCase.apply_to_variant(original), camel);
         assert_eq!(SnakeCase.apply_to_variant(original), snake);
@@ -163,7 +186,7 @@ fn rename_fields() {
         ("z42", "Z42", "Z42", "z42", "Z42", "z42", "Z42"),
     ] {
         assert_eq!(None.apply_to_field(original), original);
-        assert_eq!(UPPERCASE.apply_to_field(original), upper);
+        assert_eq!(UpperCase.apply_to_field(original), upper);
         assert_eq!(PascalCase.apply_to_field(original), pascal);
         assert_eq!(CamelCase.apply_to_field(original), camel);
         assert_eq!(SnakeCase.apply_to_field(original), original);

serde_derive/src/internals/check.rs

@@ -1,6 +1,6 @@
 use internals::ast::{Container, Data, Field, Style};
 use internals::attr::{Identifier, TagType};
-use internals::{Ctxt, Derive};
+use internals::{ungroup, Ctxt, Derive};
 use syn::{Member, Type};
 
 /// Cross-cutting checks that require looking at more than a single attrs
@@ -396,7 +396,7 @@ fn member_message(member: &Member) -> String {
 }
 
 fn allow_transparent(field: &Field, derive: Derive) -> bool {
-    if let Type::Path(ty) = field.ty {
+    if let Type::Path(ty) = ungroup(&field.ty) {
         if let Some(seg) = ty.path.segments.last() {
             if seg.ident == "PhantomData" {
                 return false;

serde_derive/src/internals/mod.rs

@@ -4,12 +4,25 @@ pub mod attr;
 mod ctxt;
 pub use self::ctxt::Ctxt;
 
+mod receiver;
+pub use self::receiver::replace_receiver;
+
 mod case;
 mod check;
+mod respan;
 mod symbol;
 
+use syn::Type;
+
 #[derive(Copy, Clone)]
 pub enum Derive {
     Serialize,
     Deserialize,
 }
+
+pub fn ungroup(mut ty: &Type) -> &Type {
+    while let Type::Group(group) = ty {
+        ty = &group.elem;
+    }
+    ty
+}

serde_derive/src/internals/receiver.rs

@@ -0,0 +1,287 @@
+use internals::respan::respan;
+use proc_macro2::Span;
+use quote::ToTokens;
+use std::mem;
+use syn::punctuated::Punctuated;
+use syn::{
+    parse_quote, Data, DeriveInput, Expr, ExprPath, GenericArgument, GenericParam, Generics, Macro,
+    Path, PathArguments, QSelf, ReturnType, Type, TypeParamBound, TypePath, WherePredicate,
+};
+
+pub fn replace_receiver(input: &mut DeriveInput) {
+    let self_ty = {
+        let ident = &input.ident;
+        let ty_generics = input.generics.split_for_impl().1;
+        parse_quote!(#ident #ty_generics)
+    };
+    let mut visitor = ReplaceReceiver(&self_ty);
+    visitor.visit_generics_mut(&mut input.generics);
+    visitor.visit_data_mut(&mut input.data);
+}
+
+struct ReplaceReceiver<'a>(&'a TypePath);
+
+impl ReplaceReceiver<'_> {
+    fn self_ty(&self, span: Span) -> TypePath {
+        let tokens = self.0.to_token_stream();
+        let respanned = respan(tokens, span);
+        syn::parse2(respanned).unwrap()
+    }
+
+    fn self_to_qself(&self, qself: &mut Option<QSelf>, path: &mut Path) {
+        if path.leading_colon.is_some() || path.segments[0].ident != "Self" {
+            return;
+        }
+
+        if path.segments.len() == 1 {
+            self.self_to_expr_path(path);
+            return;
+        }
+
+        let span = path.segments[0].ident.span();
+        *qself = Some(QSelf {
+            lt_token: Token![<](span),
+            ty: Box::new(Type::Path(self.self_ty(span))),
+            position: 0,
+            as_token: None,
+            gt_token: Token![>](span),
+        });
+
+        path.leading_colon = Some(**path.segments.pairs().next().unwrap().punct().unwrap());
+
+        let segments = mem::replace(&mut path.segments, Punctuated::new());
+        path.segments = segments.into_pairs().skip(1).collect();
+    }
+
+    fn self_to_expr_path(&self, path: &mut Path) {
+        let self_ty = self.self_ty(path.segments[0].ident.span());
+        let variant = mem::replace(path, self_ty.path);
+        for segment in &mut path.segments {
+            if let PathArguments::AngleBracketed(bracketed) = &mut segment.arguments {
+                if bracketed.colon2_token.is_none() && !bracketed.args.is_empty() {
+                    bracketed.colon2_token = Some(<Token![::]>::default());
+                }
+            }
+        }
+        if variant.segments.len() > 1 {
+            path.segments.push_punct(<Token![::]>::default());
+            path.segments.extend(variant.segments.into_pairs().skip(1));
+        }
+    }
+}
+
+impl ReplaceReceiver<'_> {
+    // `Self` -> `Receiver`
+    fn visit_type_mut(&mut self, ty: &mut Type) {
+        let span = if let Type::Path(node) = ty {
+            if node.qself.is_none() && node.path.is_ident("Self") {
+                node.path.segments[0].ident.span()
+            } else {
+                self.visit_type_path_mut(node);
+                return;
+            }
+        } else {
+            self.visit_type_mut_impl(ty);
+            return;
+        };
+        *ty = self.self_ty(span).into();
+    }
+
+    // `Self::Assoc` -> `<Receiver>::Assoc`
+    fn visit_type_path_mut(&mut self, ty: &mut TypePath) {
+        if ty.qself.is_none() {
+            self.self_to_qself(&mut ty.qself, &mut ty.path);
+        }
+        self.visit_type_path_mut_impl(ty);
+    }
+
+    // `Self::method` -> `<Receiver>::method`
+    fn visit_expr_path_mut(&mut self, expr: &mut ExprPath) {
+        if expr.qself.is_none() {
+            self.self_to_qself(&mut expr.qself, &mut expr.path);
+        }
+        self.visit_expr_path_mut_impl(expr);
+    }
+
+    // Everything below is simply traversing the syntax tree.
+
+    fn visit_type_mut_impl(&mut self, ty: &mut Type) {
+        match ty {
+            Type::Array(ty) => {
+                self.visit_type_mut(&mut ty.elem);
+                self.visit_expr_mut(&mut ty.len);
+            }
+            Type::BareFn(ty) => {
+                for arg in &mut ty.inputs {
+                    self.visit_type_mut(&mut arg.ty);
+                }
+                self.visit_return_type_mut(&mut ty.output);
+            }
+            Type::Group(ty) => self.visit_type_mut(&mut ty.elem),
+            Type::ImplTrait(ty) => {
+                for bound in &mut ty.bounds {
+                    self.visit_type_param_bound_mut(bound);
+                }
+            }
+            Type::Macro(ty) => self.visit_macro_mut(&mut ty.mac),
+            Type::Paren(ty) => self.visit_type_mut(&mut ty.elem),
+            Type::Path(ty) => {
+                if let Some(qself) = &mut ty.qself {
+                    self.visit_type_mut(&mut qself.ty);
+                }
+                self.visit_path_mut(&mut ty.path);
+            }
+            Type::Ptr(ty) => self.visit_type_mut(&mut ty.elem),
+            Type::Reference(ty) => self.visit_type_mut(&mut ty.elem),
+            Type::Slice(ty) => self.visit_type_mut(&mut ty.elem),
+            Type::TraitObject(ty) => {
+                for bound in &mut ty.bounds {
+                    self.visit_type_param_bound_mut(bound);
+                }
+            }
+            Type::Tuple(ty) => {
+                for elem in &mut ty.elems {
+                    self.visit_type_mut(elem);
+                }
+            }
+
+            Type::Infer(_) | Type::Never(_) | Type::Verbatim(_) => {}
+
+            #[cfg(test)]
+            Type::__TestExhaustive(_) => unimplemented!(),
+            #[cfg(not(test))]
+            _ => {}
+        }
+    }
+
+    fn visit_type_path_mut_impl(&mut self, ty: &mut TypePath) {
+        if let Some(qself) = &mut ty.qself {
+            self.visit_type_mut(&mut qself.ty);
+        }
+        self.visit_path_mut(&mut ty.path);
+    }
+
+    fn visit_expr_path_mut_impl(&mut self, expr: &mut ExprPath) {
+        if let Some(qself) = &mut expr.qself {
+            self.visit_type_mut(&mut qself.ty);
+        }
+        self.visit_path_mut(&mut expr.path);
+    }
+
+    fn visit_path_mut(&mut self, path: &mut Path) {
+        for segment in &mut path.segments {
+            self.visit_path_arguments_mut(&mut segment.arguments);
+        }
+    }
+
+    fn visit_path_arguments_mut(&mut self, arguments: &mut PathArguments) {
+        match arguments {
+            PathArguments::None => {}
+            PathArguments::AngleBracketed(arguments) => {
+                for arg in &mut arguments.args {
+                    match arg {
+                        GenericArgument::Type(arg) => self.visit_type_mut(arg),
+                        GenericArgument::Binding(arg) => self.visit_type_mut(&mut arg.ty),
+                        GenericArgument::Lifetime(_)
+                        | GenericArgument::Constraint(_)
+                        | GenericArgument::Const(_) => {}
+                    }
+                }
+            }
+            PathArguments::Parenthesized(arguments) => {
+                for argument in &mut arguments.inputs {
+                    self.visit_type_mut(argument);
+                }
+                self.visit_return_type_mut(&mut arguments.output);
+            }
+        }
+    }
+
+    fn visit_return_type_mut(&mut self, return_type: &mut ReturnType) {
+        match return_type {
+            ReturnType::Default => {}
+            ReturnType::Type(_, output) => self.visit_type_mut(output),
+        }
+    }
+
+    fn visit_type_param_bound_mut(&mut self, bound: &mut TypeParamBound) {
+        match bound {
+            TypeParamBound::Trait(bound) => self.visit_path_mut(&mut bound.path),
+            TypeParamBound::Lifetime(_) => {}
+        }
+    }
+
+    fn visit_generics_mut(&mut self, generics: &mut Generics) {
+        for param in &mut generics.params {
+            match param {
+                GenericParam::Type(param) => {
+                    for bound in &mut param.bounds {
+                        self.visit_type_param_bound_mut(bound);
+                    }
+                }
+                GenericParam::Lifetime(_) | GenericParam::Const(_) => {}
+            }
+        }
+        if let Some(where_clause) = &mut generics.where_clause {
+            for predicate in &mut where_clause.predicates {
+                match predicate {
+                    WherePredicate::Type(predicate) => {
+                        self.visit_type_mut(&mut predicate.bounded_ty);
+                        for bound in &mut predicate.bounds {
+                            self.visit_type_param_bound_mut(bound);
+                        }
+                    }
+                    WherePredicate::Lifetime(_) | WherePredicate::Eq(_) => {}
+                }
+            }
+        }
+    }
+
+    fn visit_data_mut(&mut self, data: &mut Data) {
+        match data {
+            Data::Struct(data) => {
+                for field in &mut data.fields {
+                    self.visit_type_mut(&mut field.ty);
+                }
+            }
+            Data::Enum(data) => {
+                for variant in &mut data.variants {
+                    for field in &mut variant.fields {
+                        self.visit_type_mut(&mut field.ty);
+                    }
+                }
+            }
+            Data::Union(_) => {}
+        }
+    }
+
+    fn visit_expr_mut(&mut self, expr: &mut Expr) {
+        match expr {
+            Expr::Binary(expr) => {
+                self.visit_expr_mut(&mut expr.left);
+                self.visit_expr_mut(&mut expr.right);
+            }
+            Expr::Call(expr) => {
+                self.visit_expr_mut(&mut expr.func);
+                for arg in &mut expr.args {
+                    self.visit_expr_mut(arg);
+                }
+            }
+            Expr::Cast(expr) => {
+                self.visit_expr_mut(&mut expr.expr);
+                self.visit_type_mut(&mut expr.ty);
+            }
+            Expr::Field(expr) => self.visit_expr_mut(&mut expr.base),
+            Expr::Index(expr) => {
+                self.visit_expr_mut(&mut expr.expr);
+                self.visit_expr_mut(&mut expr.index);
+            }
+            Expr::Paren(expr) => self.visit_expr_mut(&mut expr.expr),
+            Expr::Path(expr) => self.visit_expr_path_mut(expr),
+            Expr::Unary(expr) => self.visit_expr_mut(&mut expr.expr),
+            _ => {}
+        }
+    }
+
+    fn visit_macro_mut(&mut self, _mac: &mut Macro) {}
+}

serde_derive/src/internals/respan.rs

@@ -0,0 +1,16 @@
+use proc_macro2::{Group, Span, TokenStream, TokenTree};
+
+pub(crate) fn respan(stream: TokenStream, span: Span) -> TokenStream {
+    stream
+        .into_iter()
+        .map(|token| respan_token(token, span))
+        .collect()
+}
+
+fn respan_token(mut token: TokenTree, span: Span) -> TokenTree {
+    if let TokenTree::Group(g) = &mut token {
+        *g = Group::new(g.delimiter(), respan(g.stream(), span));
+    }
+    token.set_span(span);
+    token
+}

serde_derive/src/internals/symbol.rs

@@ -35,6 +35,7 @@ pub const TRY_FROM: Symbol = Symbol("try_from");
 pub const UNTAGGED: Symbol = Symbol("untagged");
 pub const VARIANT_IDENTIFIER: Symbol = Symbol("variant_identifier");
 pub const WITH: Symbol = Symbol("with");
+pub const EXPECTING: Symbol = Symbol("expecting");
 
 impl PartialEq<Symbol> for Ident {
     fn eq(&self, word: &Symbol) -> bool {

serde_derive/src/lib.rs

@@ -13,18 +13,23 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.108")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.125")]
 #![allow(unknown_lints, bare_trait_objects)]
 #![deny(clippy::all, clippy::pedantic)]
 // Ignored clippy lints
 #![allow(
     clippy::cognitive_complexity,
     clippy::enum_variant_names,
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6797
+    clippy::manual_map,
+    clippy::match_like_matches_macro,
     clippy::needless_pass_by_value,
     clippy::too_many_arguments,
     clippy::trivially_copy_pass_by_ref,
     clippy::used_underscore_binding,
-    clippy::wildcard_in_or_patterns
+    clippy::wildcard_in_or_patterns,
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+    clippy::unnested_or_patterns,
 )]
 // Ignored clippy_pedantic lints
 #![allow(
@@ -35,19 +40,21 @@
     clippy::filter_map,
     clippy::indexing_slicing,
     clippy::items_after_statements,
+    clippy::let_underscore_drop,
+    clippy::map_err_ignore,
     clippy::match_same_arms,
     clippy::module_name_repetitions,
     clippy::must_use_candidate,
+    clippy::option_if_let_else,
     clippy::similar_names,
     clippy::single_match_else,
     clippy::struct_excessive_bools,
     clippy::too_many_lines,
     clippy::unseparated_literal_suffix,
+    clippy::unused_self,
     clippy::use_self,
     clippy::wildcard_imports
 )]
-// The `quote!` macro requires deep recursion.
-#![recursion_limit = "512"]
 
 #[macro_use]
 extern crate quote;
@@ -75,16 +82,16 @@ mod try;
 
 #[proc_macro_derive(Serialize, attributes(serde))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
-    let input = parse_macro_input!(input as DeriveInput);
-    ser::expand_derive_serialize(&input)
+    let mut input = parse_macro_input!(input as DeriveInput);
+    ser::expand_derive_serialize(&mut input)
         .unwrap_or_else(to_compile_errors)
         .into()
 }
 
 #[proc_macro_derive(Deserialize, attributes(serde))]
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
-    let input = parse_macro_input!(input as DeriveInput);
-    de::expand_derive_deserialize(&input)
+    let mut input = parse_macro_input!(input as DeriveInput);
+    de::expand_derive_deserialize(&mut input)
         .unwrap_or_else(to_compile_errors)
         .into()
 }

serde_derive/src/pretend.rs

@@ -74,9 +74,9 @@ fn pretend_fields_used(cont: &Container) -> TokenStream {
     };
 
     quote! {
-        match _serde::export::None::<#type_ident #ty_generics> {
+        match _serde::__private::None::<#type_ident #ty_generics> {
             #(
-                _serde::export::Some(#patterns) => {}
+                _serde::__private::Some(#patterns) => {}
             )*
             _ => {}
         }
@@ -120,8 +120,8 @@ fn pretend_variants_used(cont: &Container) -> TokenStream {
         };
 
         quote! {
-            match _serde::export::None {
-                _serde::export::Some((#(#placeholders,)*)) => {
+            match _serde::__private::None {
+                _serde::__private::Some((#(#placeholders,)*)) => {
                     let _ = #type_ident::#variant_ident #turbofish #pat;
                 }
                 _ => {}

serde_derive/src/ser.rs

@@ -6,10 +6,14 @@ use bound;
 use dummy;
 use fragment::{Fragment, Match, Stmts};
 use internals::ast::{Container, Data, Field, Style, Variant};
-use internals::{attr, Ctxt, Derive};
+use internals::{attr, replace_receiver, Ctxt, Derive};
 use pretend;
 
-pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<TokenStream, Vec<syn::Error>> {
+pub fn expand_derive_serialize(
+    input: &mut syn::DeriveInput,
+) -> Result<TokenStream, Vec<syn::Error>> {
+    replace_receiver(input);
+
     let ctxt = Ctxt::new();
     let cont = match Container::from_ast(&ctxt, input, Derive::Serialize) {
         Some(cont) => cont,
@@ -29,7 +33,7 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<TokenStream,
         let used = pretend::pretend_used(&cont);
         quote! {
             impl #impl_generics #ident #ty_generics #where_clause {
-                #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> #serde::export::Result<__S::Ok, __S::Error>
+                #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> #serde::__private::Result<__S::Ok, __S::Error>
                 where
                     __S: #serde::Serializer,
                 {
@@ -42,7 +46,7 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<TokenStream,
         quote! {
             #[automatically_derived]
             impl #impl_generics #serde::Serialize for #ident #ty_generics #where_clause {
-                fn serialize<__S>(&self, __serializer: __S) -> #serde::export::Result<__S::Ok, __S::Error>
+                fn serialize<__S>(&self, __serializer: __S) -> #serde::__private::Result<__S::Ok, __S::Error>
                 where
                     __S: #serde::Serializer,
                 {
@@ -87,6 +91,9 @@ struct Parameters {
 
     /// Type has a `serde(remote = "...")` attribute.
     is_remote: bool,
+
+    /// Type has a repr(packed) attribute.
+    is_packed: bool,
 }
 
 impl Parameters {
@@ -103,6 +110,8 @@ impl Parameters {
             None => cont.ident.clone().into(),
         };
 
+        let is_packed = cont.attrs.is_packed();
+
         let generics = build_generics(cont);
 
         Parameters {
@@ -110,6 +119,7 @@ impl Parameters {
             this,
             generics,
             is_remote,
+            is_packed,
         }
     }
 
@@ -205,7 +215,7 @@ fn serialize_into(params: &Parameters, type_into: &syn::Type) -> Fragment {
     let self_var = &params.self_var;
     quote_block! {
         _serde::Serialize::serialize(
-            &_serde::export::Into::<#type_into>::into(_serde::export::Clone::clone(#self_var)),
+            &_serde::__private::Into::<#type_into>::into(_serde::__private::Clone::clone(#self_var)),
             __serializer)
     }
 }
@@ -366,7 +376,7 @@ fn serialize_struct_as_map(
     let let_mut = mut_if(serialized_fields.peek().is_some() || tag_field_exists);
 
     let len = if cattrs.has_flatten() {
-        quote!(_serde::export::None)
+        quote!(_serde::__private::None)
     } else {
         let len = serialized_fields
             .map(|field| match field.attrs.skip_serializing_if() {
@@ -380,7 +390,7 @@ fn serialize_struct_as_map(
                 quote!(#tag_field_exists as usize),
                 |sum, expr| quote!(#sum + #expr),
             );
-        quote!(_serde::export::Some(#len))
+        quote!(_serde::__private::Some(#len))
     };
 
     quote_block! {
@@ -427,7 +437,7 @@ fn serialize_variant(
             variant_ident
         );
         let skipped_err = quote! {
-            _serde::export::Err(_serde::ser::Error::custom(#skipped_msg))
+            _serde::__private::Err(_serde::ser::Error::custom(#skipped_msg))
         };
         let fields_pat = match variant.style {
             Style::Unit => quote!(),
@@ -572,7 +582,7 @@ fn serialize_internally_tagged_variant(
     if let Some(path) = variant.attrs.serialize_with() {
         let ser = wrap_serialize_variant_with(params, path, variant);
         return quote_expr! {
-            _serde::private::ser::serialize_tagged_newtype(
+            _serde::__private::ser::serialize_tagged_newtype(
                 __serializer,
                 #enum_ident_str,
                 #variant_ident_str,
@@ -601,7 +611,7 @@ fn serialize_internally_tagged_variant(
             }
 
             let span = field.original.span();
-            let func = quote_spanned!(span=> _serde::private::ser::serialize_tagged_newtype);
+            let func = quote_spanned!(span=> _serde::__private::ser::serialize_tagged_newtype);
             quote_expr! {
                 #func(
                     __serializer,
@@ -709,11 +719,11 @@ fn serialize_adjacently_tagged_variant(
     quote_block! {
         struct __AdjacentlyTagged #wrapper_generics #where_clause {
             data: (#(&'__a #fields_ty,)*),
-            phantom: _serde::export::PhantomData<#this #ty_generics>,
+            phantom: _serde::__private::PhantomData<#this #ty_generics>,
         }
 
         impl #wrapper_impl_generics _serde::Serialize for __AdjacentlyTagged #wrapper_ty_generics #where_clause {
-            fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+            fn serialize<__S>(&self, __serializer: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
             where
                 __S: _serde::Serializer,
             {
@@ -731,7 +741,7 @@ fn serialize_adjacently_tagged_variant(
         try!(_serde::ser::SerializeStruct::serialize_field(
             &mut __struct, #content, &__AdjacentlyTagged {
                 data: (#(#fields_ident,)*),
-                phantom: _serde::export::PhantomData::<#this #ty_generics>,
+                phantom: _serde::__private::PhantomData::<#this #ty_generics>,
             }));
         _serde::ser::SerializeStruct::end(__struct)
     }
@@ -972,18 +982,18 @@ fn serialize_struct_variant_with_flatten<'a>(
             quote_block! {
                 struct __EnumFlatten #wrapper_generics #where_clause {
                     data: (#(&'__a #fields_ty,)*),
-                    phantom: _serde::export::PhantomData<#this #ty_generics>,
+                    phantom: _serde::__private::PhantomData<#this #ty_generics>,
                 }
 
                 impl #wrapper_impl_generics _serde::Serialize for __EnumFlatten #wrapper_ty_generics #where_clause {
-                    fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+                    fn serialize<__S>(&self, __serializer: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
                     where
                         __S: _serde::Serializer,
                     {
                         let (#(#members,)*) = self.data;
                         let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
                             __serializer,
-                            _serde::export::None));
+                            _serde::__private::None));
                         #(#serialize_fields)*
                         _serde::ser::SerializeMap::end(__serde_state)
                     }
@@ -996,7 +1006,7 @@ fn serialize_struct_variant_with_flatten<'a>(
                     #variant_name,
                     &__EnumFlatten {
                         data: (#(#members,)*),
-                        phantom: _serde::export::PhantomData::<#this #ty_generics>,
+                        phantom: _serde::__private::PhantomData::<#this #ty_generics>,
                     })
             }
         }
@@ -1004,7 +1014,7 @@ fn serialize_struct_variant_with_flatten<'a>(
             quote_block! {
                 let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
                     __serializer,
-                    _serde::export::None));
+                    _serde::__private::None));
                 try!(_serde::ser::SerializeMap::serialize_entry(
                     &mut __serde_state,
                     #tag,
@@ -1018,7 +1028,7 @@ fn serialize_struct_variant_with_flatten<'a>(
             quote_block! {
                 let #let_mut __serde_state = try!(_serde::Serializer::serialize_map(
                     __serializer,
-                    _serde::export::None));
+                    _serde::__private::None));
                 #(#serialize_fields)*
                 _serde::ser::SerializeMap::end(__serde_state)
             }
@@ -1107,7 +1117,7 @@ fn serialize_struct_visitor(
             let ser = if field.attrs.flatten() {
                 let func = quote_spanned!(span=> _serde::Serialize::serialize);
                 quote! {
-                    try!(#func(&#field_expr, _serde::private::ser::FlatMapSerializer(&mut __serde_state)));
+                    try!(#func(&#field_expr, _serde::__private::ser::FlatMapSerializer(&mut __serde_state)));
                 }
             } else {
                 let func = struct_trait.serialize_field(span);
@@ -1202,11 +1212,11 @@ fn wrap_serialize_with(
     quote!({
         struct __SerializeWith #wrapper_impl_generics #where_clause {
             values: (#(&'__a #field_tys, )*),
-            phantom: _serde::export::PhantomData<#this #ty_generics>,
+            phantom: _serde::__private::PhantomData<#this #ty_generics>,
         }
 
         impl #wrapper_impl_generics _serde::Serialize for __SerializeWith #wrapper_ty_generics #where_clause {
-            fn serialize<__S>(&self, __s: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+            fn serialize<__S>(&self, __s: __S) -> _serde::__private::Result<__S::Ok, __S::Error>
             where
                 __S: _serde::Serializer,
             {
@@ -1216,7 +1226,7 @@ fn wrap_serialize_with(
 
         &__SerializeWith {
             values: (#(#field_exprs, )*),
-            phantom: _serde::export::PhantomData::<#this #ty_generics>,
+            phantom: _serde::__private::PhantomData::<#this #ty_generics>,
         }
     })
 }
@@ -1238,15 +1248,25 @@ fn mut_if(is_mut: bool) -> Option<TokenStream> {
 fn get_member(params: &Parameters, field: &Field, member: &Member) -> TokenStream {
     let self_var = &params.self_var;
     match (params.is_remote, field.attrs.getter()) {
-        (false, None) => quote!(&#self_var.#member),
+        (false, None) => {
+            if params.is_packed {
+                quote!(&{#self_var.#member})
+            } else {
+                quote!(&#self_var.#member)
+            }
+        }
         (true, None) => {
-            let inner = quote!(&#self_var.#member);
+            let inner = if params.is_packed {
+                quote!(&{#self_var.#member})
+            } else {
+                quote!(&#self_var.#member)
+            };
             let ty = field.ty;
-            quote!(_serde::private::ser::constrain::<#ty>(#inner))
+            quote!(_serde::__private::ser::constrain::<#ty>(#inner))
         }
         (true, Some(getter)) => {
             let ty = field.ty;
-            quote!(_serde::private::ser::constrain::<#ty>(&#getter(#self_var)))
+            quote!(_serde::__private::ser::constrain::<#ty>(&#getter(#self_var)))
         }
         (false, Some(_)) => {
             unreachable!("getter is only allowed for remote impls");

serde_derive/src/try.rs

@@ -13,9 +13,9 @@ pub fn replacement() -> TokenStream {
         macro_rules! try {
             (#dollar __expr:expr) => {
                 match #dollar __expr {
-                    _serde::export::Ok(__val) => __val,
-                    _serde::export::Err(__err) => {
-                        return _serde::export::Err(__err);
+                    _serde::__private::Ok(__val) => __val,
+                    _serde::__private::Err(__err) => {
+                        return _serde::__private::Err(__err);
                     }
                 }
             }

serde_derive_internals/Cargo.toml

@@ -8,7 +8,7 @@ homepage = "https://serde.rs"
 repository = "https://github.com/serde-rs/serde"
 documentation = "https://docs.rs/serde_derive_internals"
 keywords = ["serde", "serialization"]
-include = ["Cargo.toml", "lib.rs", "src/**/*.rs", "LICENSE-APACHE", "LICENSE-MIT"]
+include = ["lib.rs", "src/**/*.rs", "LICENSE-APACHE", "LICENSE-MIT"]
 
 [lib]
 path = "lib.rs"
@@ -16,7 +16,7 @@ path = "lib.rs"
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "1.0", default-features = false, features = ["derive", "parsing", "printing", "clone-impls"] }
+syn = { version = "1.0.60", default-features = false, features = ["derive", "parsing", "printing", "clone-impls"] }
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]

serde_derive_internals/lib.rs

@@ -1,14 +1,35 @@
 #![doc(html_root_url = "https://docs.rs/serde_derive_internals/0.25.0")]
 #![allow(unknown_lints, bare_trait_objects)]
-#![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
-#![cfg_attr(
-    feature = "cargo-clippy",
-    allow(
-        cognitive_complexity,
-        redundant_field_names,
-        trivially_copy_pass_by_ref,
-        wildcard_in_or_patterns
-    )
+#![deny(clippy::all, clippy::pedantic)]
+// Ignored clippy lints
+#![allow(
+    clippy::cognitive_complexity,
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/6797
+    clippy::manual_map,
+    clippy::missing_panics_doc,
+    clippy::redundant_field_names,
+    clippy::result_unit_err,
+    clippy::should_implement_trait,
+    clippy::trivially_copy_pass_by_ref,
+    clippy::wildcard_in_or_patterns,
+    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+    clippy::unnested_or_patterns,
+)]
+// Ignored clippy_pedantic lints
+#![allow(
+    clippy::doc_markdown,
+    clippy::enum_glob_use,
+    clippy::items_after_statements,
+    clippy::let_underscore_drop,
+    clippy::match_same_arms,
+    clippy::missing_errors_doc,
+    clippy::module_name_repetitions,
+    clippy::must_use_candidate,
+    clippy::similar_names,
+    clippy::struct_excessive_bools,
+    clippy::too_many_lines,
+    clippy::unused_self,
+    clippy::wildcard_imports
 )]
 
 #[macro_use]

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "1.0.108" # remember to update html_root_url
+version = "1.0.125" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT OR Apache-2.0"
 description = "Token De/Serializer for testing De/Serialize implementations"
@@ -9,7 +9,7 @@ repository = "https://github.com/serde-rs/serde"
 documentation = "https://docs.serde.rs/serde_test/"
 keywords = ["serde", "serialization"]
 readme = "crates-io.md"
-include = ["Cargo.toml", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
+include = ["src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APACHE", "LICENSE-MIT"]
 
 [dependencies]
 serde = { version = "1.0.60", path = "../serde" }

serde_test/build.rs

@@ -0,0 +1,30 @@
+use std::env;
+use std::process::Command;
+use std::str;
+
+// The rustc-cfg strings below are *not* public API. Please let us know by
+// opening a GitHub issue if your build environment requires some way to enable
+// these cfgs other than by executing our build script.
+fn main() {
+    let minor = match rustc_minor_version() {
+        Some(minor) => minor,
+        None => return,
+    };
+
+    // #[track_caller] stabilized in Rust 1.46:
+    // https://blog.rust-lang.org/2020/08/27/Rust-1.46.0.html#track_caller
+    if minor >= 46 {
+        println!("cargo:rustc-cfg=track_caller");
+    }
+}
+
+fn rustc_minor_version() -> Option<u32> {
+    let rustc = env::var_os("RUSTC")?;
+    let output = Command::new(rustc).arg("--version").output().ok()?;
+    let version = str::from_utf8(&output.stdout).ok()?;
+    let mut pieces = version.split('.');
+    if pieces.next() != Some("rustc 1") {
+        return None;
+    }
+    pieces.next()?.parse().ok()
+}

serde_test/src/assert.rs

@@ -28,6 +28,7 @@ use std::fmt::Debug;
 ///     Token::StructEnd,
 /// ]);
 /// ```
+#[cfg_attr(track_caller, track_caller)]
 pub fn assert_tokens<'de, T>(value: &T, tokens: &'de [Token])
 where
     T: Serialize + Deserialize<'de> + PartialEq + Debug,
@@ -58,6 +59,7 @@ where
 ///     Token::StructEnd,
 /// ]);
 /// ```
+#[cfg_attr(track_caller, track_caller)]
 pub fn assert_ser_tokens<T>(value: &T, tokens: &[Token])
 where
     T: Serialize,
@@ -110,6 +112,7 @@ where
 ///     assert_ser_tokens_error(&example, expected, error);
 /// }
 /// ```
+#[cfg_attr(track_caller, track_caller)]
 pub fn assert_ser_tokens_error<T>(value: &T, tokens: &[Token], error: &str)
 where
     T: Serialize,
@@ -147,6 +150,7 @@ where
 ///     Token::StructEnd,
 /// ]);
 /// ```
+#[cfg_attr(track_caller, track_caller)]
 pub fn assert_de_tokens<'de, T>(value: &T, tokens: &'de [Token])
 where
     T: Deserialize<'de> + PartialEq + Debug,
@@ -199,6 +203,7 @@ where
 ///     "unknown field `x`, expected `a` or `b`",
 /// );
 /// ```
+#[cfg_attr(track_caller, track_caller)]
 pub fn assert_de_tokens_error<'de, T>(tokens: &'de [Token], error: &str)
 where
     T: Deserialize<'de>,

serde_test/src/configure.rs

@@ -777,6 +777,17 @@ macro_rules! impl_deserializer {
             {
                 self.0.next_value_seed($wrapper(seed))
             }
+            fn next_entry_seed<K, V>(
+                &mut self,
+                kseed: K,
+                vseed: V,
+            ) -> Result<Option<(K::Value, V::Value)>, D::Error>
+            where
+                K: DeserializeSeed<'de>,
+                V: DeserializeSeed<'de>,
+            {
+                self.0.next_entry_seed($wrapper(kseed), $wrapper(vseed))
+            }
             fn size_hint(&self) -> Option<usize> {
                 self.0.size_hint()
             }

serde_test/src/de.rs

@@ -168,14 +168,42 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
                         self.next_token();
                         visitor.visit_str(variant)
                     }
+                    (Token::BorrowedStr(variant), Token::Unit) => {
+                        self.next_token();
+                        visitor.visit_borrowed_str(variant)
+                    }
+                    (Token::String(variant), Token::Unit) => {
+                        self.next_token();
+                        visitor.visit_string(variant.to_string())
+                    }
                     (Token::Bytes(variant), Token::Unit) => {
                         self.next_token();
                         visitor.visit_bytes(variant)
                     }
+                    (Token::BorrowedBytes(variant), Token::Unit) => {
+                        self.next_token();
+                        visitor.visit_borrowed_bytes(variant)
+                    }
+                    (Token::ByteBuf(variant), Token::Unit) => {
+                        self.next_token();
+                        visitor.visit_byte_buf(variant.to_vec())
+                    }
+                    (Token::U8(variant), Token::Unit) => {
+                        self.next_token();
+                        visitor.visit_u8(variant)
+                    }
+                    (Token::U16(variant), Token::Unit) => {
+                        self.next_token();
+                        visitor.visit_u16(variant)
+                    }
                     (Token::U32(variant), Token::Unit) => {
                         self.next_token();
                         visitor.visit_u32(variant)
                     }
+                    (Token::U64(variant), Token::Unit) => {
+                        self.next_token();
+                        visitor.visit_u64(variant)
+                    }
                     (variant, Token::Unit) => unexpected!(variant),
                     (variant, _) => {
                         visitor.visit_map(EnumMapVisitor::new(self, variant, EnumFormat::Any))
@@ -250,9 +278,7 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
             {
                 visitor.visit_enum(DeserializerEnumVisitor { de: self })
             }
-            _ => {
-                unexpected!(self.next_token());
-            }
+            _ => self.deserialize_any(visitor),
         }
     }
 

serde_test/src/lib.rs

@@ -144,7 +144,7 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.108")]
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.125")]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
 // Ignored clippy lints
@@ -155,9 +155,11 @@
     allow(
         empty_line_after_outer_attr,
         missing_docs_in_private_items,
+        missing_panics_doc,
         module_name_repetitions,
         must_use_candidate,
         redundant_field_names,
+        too_many_lines,
         use_debug,
         use_self
     )

serde_test/src/ser.rs

@@ -32,18 +32,18 @@ impl<'a> Serializer<'a> {
 }
 
 macro_rules! assert_next_token {
-    ($ser:expr, $expected:ident) => {
-        assert_next_token!($ser, stringify!($expected), Token::$expected, true);
+    ($ser:expr, $actual:ident) => {
+        assert_next_token!($ser, stringify!($actual), Token::$actual, true);
     };
-    ($ser:expr, $expected:ident($v:expr)) => {
+    ($ser:expr, $actual:ident($v:expr)) => {
         assert_next_token!(
             $ser,
-            format_args!(concat!(stringify!($expected), "({:?})"), $v),
-            Token::$expected(v),
+            format_args!(concat!(stringify!($actual), "({:?})"), $v),
+            Token::$actual(v),
             v == $v
         );
     };
-    ($ser:expr, $expected:ident { $($k:ident),* }) => {
+    ($ser:expr, $actual:ident { $($k:ident),* }) => {
         let compare = ($($k,)*);
         let field_format = || {
             use std::fmt::Write;
@@ -55,21 +55,21 @@ macro_rules! assert_next_token {
         };
         assert_next_token!(
             $ser,
-            format_args!(concat!(stringify!($expected), " {{ {}}}"), field_format()),
-            Token::$expected { $($k),* },
+            format_args!(concat!(stringify!($actual), " {{ {}}}"), field_format()),
+            Token::$actual { $($k),* },
             ($($k,)*) == compare
         );
     };
-    ($ser:expr, $expected:expr, $pat:pat, $guard:expr) => {
+    ($ser:expr, $actual:expr, $pat:pat, $guard:expr) => {
         match $ser.next_token() {
             Some($pat) if $guard => {}
-            Some(other) => {
+            Some(expected) => {
                 panic!("expected Token::{} but serialized as {}",
-                       $expected, other);
+                       expected, $actual);
             }
             None => {
-                panic!("expected Token::{} after end of serialized tokens",
-                       $expected);
+                panic!("expected end of tokens, but {} was serialized",
+                       $actual);
             }
         }
     };

test_suite/Cargo.toml

@@ -23,4 +23,4 @@ rustversion = "1.0"
 serde = { path = "../serde", features = ["rc", "derive"] }
 serde_derive = { path = "../serde_derive", features = ["deserialize_in_place"] }
 serde_test = { path = "../serde_test" }
-trybuild = "1.0"
+trybuild = { version = "1.0.19", features = ["diff"] }

test_suite/tests/expand/default_ty_param.expanded.rs

@@ -10,12 +10,15 @@ struct DefaultTyParam<T: AssociatedType<X = i32> = i32> {
 }
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_DefaultTyParam: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
     impl<T: AssociatedType<X = i32>> _serde::Serialize for DefaultTyParam<T> {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -24,9 +27,9 @@ const _IMPL_SERIALIZE_FOR_DefaultTyParam: () = {
                 "DefaultTyParam",
                 false as usize + 1,
             ) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             match _serde::ser::SerializeStruct::serialize_field(
@@ -34,9 +37,9 @@ const _IMPL_SERIALIZE_FOR_DefaultTyParam: () = {
                 "phantom",
                 &self.phantom,
             ) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             _serde::ser::SerializeStruct::end(__serde_state)
@@ -45,12 +48,12 @@ const _IMPL_SERIALIZE_FOR_DefaultTyParam: () = {
 };
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
     impl<'de, T: AssociatedType<X = i32>> _serde::Deserialize<'de> for DefaultTyParam<T> {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -64,47 +67,49 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        0u64 => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"field index 0 <= i < 1",
-                        )),
+                        0u64 => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        "phantom" => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        "phantom" => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        b"phantom" => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        b"phantom" => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -112,76 +117,77 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                 }
             }
             struct __Visitor<'de, T: AssociatedType<X = i32>> {
-                marker: _serde::export::PhantomData<DefaultTyParam<T>>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<DefaultTyParam<T>>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, T: AssociatedType<X = i32>> _serde::de::Visitor<'de> for __Visitor<'de, T> {
                 type Value = DefaultTyParam<T>;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "struct DefaultTyParam")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "struct DefaultTyParam")
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
                     let __field0 = match match _serde::de::SeqAccess::next_element::<PhantomData<T>>(
                         &mut __seq,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 0usize,
                                 &"struct DefaultTyParam with 1 element",
                             ));
                         }
                     };
-                    _serde::export::Ok(DefaultTyParam { phantom: __field0 })
+                    _serde::__private::Ok(DefaultTyParam { phantom: __field0 })
                 }
                 #[inline]
                 fn visit_map<__A>(
                     self,
                     mut __map: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::MapAccess<'de>,
                 {
-                    let mut __field0: _serde::export::Option<PhantomData<T>> = _serde::export::None;
-                    while let _serde::export::Some(__key) =
+                    let mut __field0: _serde::__private::Option<PhantomData<T>> =
+                        _serde::__private::None;
+                    while let _serde::__private::Some(__key) =
                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         }
                     {
                         match __key {
                             __Field::__field0 => {
-                                if _serde::export::Option::is_some(&__field0) {
-                                    return _serde::export::Err(
+                                if _serde::__private::Option::is_some(&__field0) {
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field(
                                             "phantom",
                                         ),
                                     );
                                 }
-                                __field0 = _serde::export::Some(
+                                __field0 = _serde::__private::Some(
                                     match _serde::de::MapAccess::next_value::<PhantomData<T>>(
                                         &mut __map,
                                     ) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     },
                                 );
@@ -191,25 +197,26 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                                     _serde::de::IgnoredAny,
                                 >(&mut __map)
                                 {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                             }
                         }
                     }
                     let __field0 = match __field0 {
-                        _serde::export::Some(__field0) => __field0,
-                        _serde::export::None => match _serde::private::de::missing_field("phantom")
-                        {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        _serde::__private::Some(__field0) => __field0,
+                        _serde::__private::None => {
+                            match _serde::__private::de::missing_field("phantom") {
+                                _serde::__private::Ok(__val) => __val,
+                                _serde::__private::Err(__err) => {
+                                    return _serde::__private::Err(__err);
+                                }
                             }
-                        },
+                        }
                     };
-                    _serde::export::Ok(DefaultTyParam { phantom: __field0 })
+                    _serde::__private::Ok(DefaultTyParam { phantom: __field0 })
                 }
             }
             const FIELDS: &'static [&'static str] = &["phantom"];
@@ -218,15 +225,15 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                 "DefaultTyParam",
                 FIELDS,
                 __Visitor {
-                    marker: _serde::export::PhantomData::<DefaultTyParam<T>>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<DefaultTyParam<T>>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }
         fn deserialize_in_place<__D>(
             __deserializer: __D,
             __place: &mut Self,
-        ) -> _serde::export::Result<(), __D::Error>
+        ) -> _serde::__private::Result<(), __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -240,47 +247,49 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        0u64 => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"field index 0 <= i < 1",
-                        )),
+                        0u64 => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        "phantom" => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        "phantom" => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        b"phantom" => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        b"phantom" => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -289,7 +298,7 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
             }
             struct __Visitor<'de, 'place, T: AssociatedType<X = i32> + 'place> {
                 place: &'place mut DefaultTyParam<T>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, 'place, T: AssociatedType<X = i32> + 'place> _serde::de::Visitor<'de>
                 for __Visitor<'de, 'place, T>
@@ -297,55 +306,55 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                 type Value = ();
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "struct DefaultTyParam")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "struct DefaultTyParam")
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.phantom),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.phantom),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             0usize,
                             &"struct DefaultTyParam with 1 element",
                         ));
                     }
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
                 #[inline]
                 fn visit_map<__A>(
                     self,
                     mut __map: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::MapAccess<'de>,
                 {
                     let mut __field0: bool = false;
-                    while let _serde::export::Some(__key) =
+                    while let _serde::__private::Some(__key) =
                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         }
                     {
                         match __key {
                             __Field::__field0 => {
                                 if __field0 {
-                                    return _serde::export::Err(
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field(
                                             "phantom",
                                         ),
@@ -353,11 +362,11 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                                 }
                                 match _serde::de::MapAccess::next_value_seed(
                                     &mut __map,
-                                    _serde::private::de::InPlaceSeed(&mut self.place.phantom),
+                                    _serde::__private::de::InPlaceSeed(&mut self.place.phantom),
                                 ) {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                                 __field0 = true;
@@ -367,23 +376,23 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                                     _serde::de::IgnoredAny,
                                 >(&mut __map)
                                 {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                             }
                         }
                     }
                     if !__field0 {
-                        self.place.phantom = match _serde::private::de::missing_field("phantom") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        self.place.phantom = match _serde::__private::de::missing_field("phantom") {
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         };
                     };
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
             }
             const FIELDS: &'static [&'static str] = &["phantom"];
@@ -393,7 +402,7 @@ const _IMPL_DESERIALIZE_FOR_DefaultTyParam: () = {
                 FIELDS,
                 __Visitor {
                     place: __place,
-                    lifetime: _serde::export::PhantomData,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }

test_suite/tests/expand/generic_enum.expanded.rs

@@ -7,7 +7,7 @@ pub enum GenericEnum<T, U> {
 }
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_GenericEnum: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -16,7 +16,10 @@ const _IMPL_SERIALIZE_FOR_GenericEnum: () = {
         T: _serde::Serialize,
         U: _serde::Serialize,
     {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -44,27 +47,27 @@ const _IMPL_SERIALIZE_FOR_GenericEnum: () = {
                         "Seq",
                         0 + 1 + 1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field0,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     _serde::ser::SerializeTupleVariant::end(__serde_state)
@@ -77,9 +80,9 @@ const _IMPL_SERIALIZE_FOR_GenericEnum: () = {
                         "Map",
                         0 + 1 + 1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -87,9 +90,9 @@ const _IMPL_SERIALIZE_FOR_GenericEnum: () = {
                         "x",
                         x,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -97,9 +100,9 @@ const _IMPL_SERIALIZE_FOR_GenericEnum: () = {
                         "y",
                         y,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     _serde::ser::SerializeStructVariant::end(__serde_state)
@@ -110,7 +113,7 @@ const _IMPL_SERIALIZE_FOR_GenericEnum: () = {
 };
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -119,7 +122,7 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
         T: _serde::Deserialize<'de>,
         U: _serde::Deserialize<'de>,
     {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -135,35 +138,38 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "variant identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "variant identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        0u64 => _serde::export::Ok(__Field::__field0),
-                        1u64 => _serde::export::Ok(__Field::__field1),
-                        2u64 => _serde::export::Ok(__Field::__field2),
-                        3u64 => _serde::export::Ok(__Field::__field3),
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                        0u64 => _serde::__private::Ok(__Field::__field0),
+                        1u64 => _serde::__private::Ok(__Field::__field1),
+                        2u64 => _serde::__private::Ok(__Field::__field2),
+                        3u64 => _serde::__private::Ok(__Field::__field3),
+                        _ => _serde::__private::Err(_serde::de::Error::invalid_value(
                             _serde::de::Unexpected::Unsigned(__value),
                             &"variant index 0 <= i < 4",
                         )),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        "Unit" => _serde::export::Ok(__Field::__field0),
-                        "NewType" => _serde::export::Ok(__Field::__field1),
-                        "Seq" => _serde::export::Ok(__Field::__field2),
-                        "Map" => _serde::export::Ok(__Field::__field3),
-                        _ => _serde::export::Err(_serde::de::Error::unknown_variant(
+                        "Unit" => _serde::__private::Ok(__Field::__field0),
+                        "NewType" => _serde::__private::Ok(__Field::__field1),
+                        "Seq" => _serde::__private::Ok(__Field::__field2),
+                        "Map" => _serde::__private::Ok(__Field::__field3),
+                        _ => _serde::__private::Err(_serde::de::Error::unknown_variant(
                             __value, VARIANTS,
                         )),
                     }
@@ -171,18 +177,18 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        b"Unit" => _serde::export::Ok(__Field::__field0),
-                        b"NewType" => _serde::export::Ok(__Field::__field1),
-                        b"Seq" => _serde::export::Ok(__Field::__field2),
-                        b"Map" => _serde::export::Ok(__Field::__field3),
+                        b"Unit" => _serde::__private::Ok(__Field::__field0),
+                        b"NewType" => _serde::__private::Ok(__Field::__field1),
+                        b"Seq" => _serde::__private::Ok(__Field::__field2),
+                        b"Map" => _serde::__private::Ok(__Field::__field3),
                         _ => {
-                            let __value = &_serde::export::from_utf8_lossy(__value);
-                            _serde::export::Err(_serde::de::Error::unknown_variant(
+                            let __value = &_serde::__private::from_utf8_lossy(__value);
+                            _serde::__private::Err(_serde::de::Error::unknown_variant(
                                 __value, VARIANTS,
                             ))
                         }
@@ -191,7 +197,9 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -203,8 +211,8 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                 T: _serde::Deserialize<'de>,
                 U: _serde::Deserialize<'de>,
             {
-                marker: _serde::export::PhantomData<GenericEnum<T, U>>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<GenericEnum<T, U>>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, T, U> _serde::de::Visitor<'de> for __Visitor<'de, T, U>
             where
@@ -214,33 +222,33 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                 type Value = GenericEnum<T, U>;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "enum GenericEnum")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "enum GenericEnum")
                 }
                 fn visit_enum<__A>(
                     self,
                     __data: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::EnumAccess<'de>,
                 {
                     match match _serde::de::EnumAccess::variant(__data) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
                         (__Field::__field0, __variant) => {
                             match _serde::de::VariantAccess::unit_variant(__variant) {
-                                _serde::export::Ok(__val) => __val,
-                                _serde::export::Err(__err) => {
-                                    return _serde::export::Err(__err);
+                                _serde::__private::Ok(__val) => __val,
+                                _serde::__private::Err(__err) => {
+                                    return _serde::__private::Err(__err);
                                 }
                             };
-                            _serde::export::Ok(GenericEnum::Unit)
+                            _serde::__private::Ok(GenericEnum::Unit)
                         }
-                        (__Field::__field1, __variant) => _serde::export::Result::map(
+                        (__Field::__field1, __variant) => _serde::__private::Result::map(
                             _serde::de::VariantAccess::newtype_variant::<T>(__variant),
                             GenericEnum::NewType,
                         ),
@@ -250,8 +258,8 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 T: _serde::Deserialize<'de>,
                                 U: _serde::Deserialize<'de>,
                             {
-                                marker: _serde::export::PhantomData<GenericEnum<T, U>>,
-                                lifetime: _serde::export::PhantomData<&'de ()>,
+                                marker: _serde::__private::PhantomData<GenericEnum<T, U>>,
+                                lifetime: _serde::__private::PhantomData<&'de ()>,
                             }
                             impl<'de, T, U> _serde::de::Visitor<'de> for __Visitor<'de, T, U>
                             where
@@ -261,9 +269,10 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 type Value = GenericEnum<T, U>;
                                 fn expecting(
                                     &self,
-                                    __formatter: &mut _serde::export::Formatter,
-                                ) -> _serde::export::fmt::Result {
-                                    _serde::export::Formatter::write_str(
+                                    __formatter: &mut _serde::__private::Formatter,
+                                ) -> _serde::__private::fmt::Result
+                                {
+                                    _serde::__private::Formatter::write_str(
                                         __formatter,
                                         "tuple variant GenericEnum::Seq",
                                     )
@@ -272,7 +281,7 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 fn visit_seq<__A>(
                                     self,
                                     mut __seq: __A,
-                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                ) -> _serde::__private::Result<Self::Value, __A::Error>
                                 where
                                     __A: _serde::de::SeqAccess<'de>,
                                 {
@@ -281,14 +290,14 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                     >(
                                         &mut __seq
                                     ) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     } {
-                                        _serde::export::Some(__value) => __value,
-                                        _serde::export::None => {
-                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 0usize , & "tuple variant GenericEnum::Seq with 2 elements" ) ) ;
+                                        _serde::__private::Some(__value) => __value,
+                                        _serde::__private::None => {
+                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (0usize , & "tuple variant GenericEnum::Seq with 2 elements")) ;
                                         }
                                     };
                                     let __field1 = match match _serde::de::SeqAccess::next_element::<
@@ -296,25 +305,25 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                     >(
                                         &mut __seq
                                     ) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     } {
-                                        _serde::export::Some(__value) => __value,
-                                        _serde::export::None => {
-                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 1usize , & "tuple variant GenericEnum::Seq with 2 elements" ) ) ;
+                                        _serde::__private::Some(__value) => __value,
+                                        _serde::__private::None => {
+                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (1usize , & "tuple variant GenericEnum::Seq with 2 elements")) ;
                                         }
                                     };
-                                    _serde::export::Ok(GenericEnum::Seq(__field0, __field1))
+                                    _serde::__private::Ok(GenericEnum::Seq(__field0, __field1))
                                 }
                             }
                             _serde::de::VariantAccess::tuple_variant(
                                 __variant,
                                 2usize,
                                 __Visitor {
-                                    marker: _serde::export::PhantomData::<GenericEnum<T, U>>,
-                                    lifetime: _serde::export::PhantomData,
+                                    marker: _serde::__private::PhantomData::<GenericEnum<T, U>>,
+                                    lifetime: _serde::__private::PhantomData,
                                 },
                             )
                         }
@@ -330,9 +339,10 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 type Value = __Field;
                                 fn expecting(
                                     &self,
-                                    __formatter: &mut _serde::export::Formatter,
-                                ) -> _serde::export::fmt::Result {
-                                    _serde::export::Formatter::write_str(
+                                    __formatter: &mut _serde::__private::Formatter,
+                                ) -> _serde::__private::fmt::Result
+                                {
+                                    _serde::__private::Formatter::write_str(
                                         __formatter,
                                         "field identifier",
                                     )
@@ -340,43 +350,40 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 fn visit_u64<__E>(
                                     self,
                                     __value: u64,
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        0u64 => _serde::export::Ok(__Field::__field0),
-                                        1u64 => _serde::export::Ok(__Field::__field1),
-                                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                                            _serde::de::Unexpected::Unsigned(__value),
-                                            &"field index 0 <= i < 2",
-                                        )),
+                                        0u64 => _serde::__private::Ok(__Field::__field0),
+                                        1u64 => _serde::__private::Ok(__Field::__field1),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                                 fn visit_str<__E>(
                                     self,
                                     __value: &str,
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        "x" => _serde::export::Ok(__Field::__field0),
-                                        "y" => _serde::export::Ok(__Field::__field1),
-                                        _ => _serde::export::Ok(__Field::__ignore),
+                                        "x" => _serde::__private::Ok(__Field::__field0),
+                                        "y" => _serde::__private::Ok(__Field::__field1),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                                 fn visit_bytes<__E>(
                                     self,
                                     __value: &[u8],
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        b"x" => _serde::export::Ok(__Field::__field0),
-                                        b"y" => _serde::export::Ok(__Field::__field1),
-                                        _ => _serde::export::Ok(__Field::__ignore),
+                                        b"x" => _serde::__private::Ok(__Field::__field0),
+                                        b"y" => _serde::__private::Ok(__Field::__field1),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                             }
@@ -384,7 +391,7 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 #[inline]
                                 fn deserialize<__D>(
                                     __deserializer: __D,
-                                ) -> _serde::export::Result<Self, __D::Error>
+                                ) -> _serde::__private::Result<Self, __D::Error>
                                 where
                                     __D: _serde::Deserializer<'de>,
                                 {
@@ -399,8 +406,8 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 T: _serde::Deserialize<'de>,
                                 U: _serde::Deserialize<'de>,
                             {
-                                marker: _serde::export::PhantomData<GenericEnum<T, U>>,
-                                lifetime: _serde::export::PhantomData<&'de ()>,
+                                marker: _serde::__private::PhantomData<GenericEnum<T, U>>,
+                                lifetime: _serde::__private::PhantomData<&'de ()>,
                             }
                             impl<'de, T, U> _serde::de::Visitor<'de> for __Visitor<'de, T, U>
                             where
@@ -410,9 +417,10 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 type Value = GenericEnum<T, U>;
                                 fn expecting(
                                     &self,
-                                    __formatter: &mut _serde::export::Formatter,
-                                ) -> _serde::export::fmt::Result {
-                                    _serde::export::Formatter::write_str(
+                                    __formatter: &mut _serde::__private::Formatter,
+                                ) -> _serde::__private::fmt::Result
+                                {
+                                    _serde::__private::Formatter::write_str(
                                         __formatter,
                                         "struct variant GenericEnum::Map",
                                     )
@@ -421,7 +429,7 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 fn visit_seq<__A>(
                                     self,
                                     mut __seq: __A,
-                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                ) -> _serde::__private::Result<Self::Value, __A::Error>
                                 where
                                     __A: _serde::de::SeqAccess<'de>,
                                 {
@@ -430,14 +438,14 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                     >(
                                         &mut __seq
                                     ) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     } {
-                                        _serde::export::Some(__value) => __value,
-                                        _serde::export::None => {
-                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 0usize , & "struct variant GenericEnum::Map with 2 elements" ) ) ;
+                                        _serde::__private::Some(__value) => __value,
+                                        _serde::__private::None => {
+                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (0usize , & "struct variant GenericEnum::Map with 2 elements")) ;
                                         }
                                     };
                                     let __field1 = match match _serde::de::SeqAccess::next_element::<
@@ -445,17 +453,17 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                     >(
                                         &mut __seq
                                     ) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     } {
-                                        _serde::export::Some(__value) => __value,
-                                        _serde::export::None => {
-                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 1usize , & "struct variant GenericEnum::Map with 2 elements" ) ) ;
+                                        _serde::__private::Some(__value) => __value,
+                                        _serde::__private::None => {
+                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (1usize , & "struct variant GenericEnum::Map with 2 elements")) ;
                                         }
                                     };
-                                    _serde::export::Ok(GenericEnum::Map {
+                                    _serde::__private::Ok(GenericEnum::Map {
                                         x: __field0,
                                         y: __field1,
                                     })
@@ -464,50 +472,50 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 fn visit_map<__A>(
                                     self,
                                     mut __map: __A,
-                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                ) -> _serde::__private::Result<Self::Value, __A::Error>
                                 where
                                     __A: _serde::de::MapAccess<'de>,
                                 {
-                                    let mut __field0: _serde::export::Option<T> =
-                                        _serde::export::None;
-                                    let mut __field1: _serde::export::Option<U> =
-                                        _serde::export::None;
-                                    while let _serde::export::Some(__key) =
+                                    let mut __field0: _serde::__private::Option<T> =
+                                        _serde::__private::None;
+                                    let mut __field1: _serde::__private::Option<U> =
+                                        _serde::__private::None;
+                                    while let _serde::__private::Some(__key) =
                                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
                                         {
-                                            _serde::export::Ok(__val) => __val,
-                                            _serde::export::Err(__err) => {
-                                                return _serde::export::Err(__err);
+                                            _serde::__private::Ok(__val) => __val,
+                                            _serde::__private::Err(__err) => {
+                                                return _serde::__private::Err(__err);
                                             }
                                         }
                                     {
                                         match __key {
                                             __Field::__field0 => {
-                                                if _serde::export::Option::is_some(&__field0) {
-                                                    return _serde :: export :: Err ( < __A :: Error as _serde :: de :: Error > :: duplicate_field ( "x" ) ) ;
+                                                if _serde::__private::Option::is_some(&__field0) {
+                                                    return _serde :: __private :: Err (< __A :: Error as _serde :: de :: Error > :: duplicate_field ("x")) ;
                                                 }
-                                                __field0 = _serde::export::Some(
+                                                __field0 = _serde::__private::Some(
                                                     match _serde::de::MapAccess::next_value::<T>(
                                                         &mut __map,
                                                     ) {
-                                                        _serde::export::Ok(__val) => __val,
-                                                        _serde::export::Err(__err) => {
-                                                            return _serde::export::Err(__err);
+                                                        _serde::__private::Ok(__val) => __val,
+                                                        _serde::__private::Err(__err) => {
+                                                            return _serde::__private::Err(__err);
                                                         }
                                                     },
                                                 );
                                             }
                                             __Field::__field1 => {
-                                                if _serde::export::Option::is_some(&__field1) {
-                                                    return _serde :: export :: Err ( < __A :: Error as _serde :: de :: Error > :: duplicate_field ( "y" ) ) ;
+                                                if _serde::__private::Option::is_some(&__field1) {
+                                                    return _serde :: __private :: Err (< __A :: Error as _serde :: de :: Error > :: duplicate_field ("y")) ;
                                                 }
-                                                __field1 = _serde::export::Some(
+                                                __field1 = _serde::__private::Some(
                                                     match _serde::de::MapAccess::next_value::<U>(
                                                         &mut __map,
                                                     ) {
-                                                        _serde::export::Ok(__val) => __val,
-                                                        _serde::export::Err(__err) => {
-                                                            return _serde::export::Err(__err);
+                                                        _serde::__private::Ok(__val) => __val,
+                                                        _serde::__private::Err(__err) => {
+                                                            return _serde::__private::Err(__err);
                                                         }
                                                     },
                                                 );
@@ -518,37 +526,37 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                                 >(
                                                     &mut __map
                                                 ) {
-                                                    _serde::export::Ok(__val) => __val,
-                                                    _serde::export::Err(__err) => {
-                                                        return _serde::export::Err(__err);
+                                                    _serde::__private::Ok(__val) => __val,
+                                                    _serde::__private::Err(__err) => {
+                                                        return _serde::__private::Err(__err);
                                                     }
                                                 };
                                             }
                                         }
                                     }
                                     let __field0 = match __field0 {
-                                        _serde::export::Some(__field0) => __field0,
-                                        _serde::export::None => {
-                                            match _serde::private::de::missing_field("x") {
-                                                _serde::export::Ok(__val) => __val,
-                                                _serde::export::Err(__err) => {
-                                                    return _serde::export::Err(__err);
+                                        _serde::__private::Some(__field0) => __field0,
+                                        _serde::__private::None => {
+                                            match _serde::__private::de::missing_field("x") {
+                                                _serde::__private::Ok(__val) => __val,
+                                                _serde::__private::Err(__err) => {
+                                                    return _serde::__private::Err(__err);
                                                 }
                                             }
                                         }
                                     };
                                     let __field1 = match __field1 {
-                                        _serde::export::Some(__field1) => __field1,
-                                        _serde::export::None => {
-                                            match _serde::private::de::missing_field("y") {
-                                                _serde::export::Ok(__val) => __val,
-                                                _serde::export::Err(__err) => {
-                                                    return _serde::export::Err(__err);
+                                        _serde::__private::Some(__field1) => __field1,
+                                        _serde::__private::None => {
+                                            match _serde::__private::de::missing_field("y") {
+                                                _serde::__private::Ok(__val) => __val,
+                                                _serde::__private::Err(__err) => {
+                                                    return _serde::__private::Err(__err);
                                                 }
                                             }
                                         }
                                     };
-                                    _serde::export::Ok(GenericEnum::Map {
+                                    _serde::__private::Ok(GenericEnum::Map {
                                         x: __field0,
                                         y: __field1,
                                     })
@@ -559,8 +567,8 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                                 __variant,
                                 FIELDS,
                                 __Visitor {
-                                    marker: _serde::export::PhantomData::<GenericEnum<T, U>>,
-                                    lifetime: _serde::export::PhantomData,
+                                    marker: _serde::__private::PhantomData::<GenericEnum<T, U>>,
+                                    lifetime: _serde::__private::PhantomData,
                                 },
                             )
                         }
@@ -573,8 +581,8 @@ const _IMPL_DESERIALIZE_FOR_GenericEnum: () = {
                 "GenericEnum",
                 VARIANTS,
                 __Visitor {
-                    marker: _serde::export::PhantomData::<GenericEnum<T, U>>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<GenericEnum<T, U>>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }

test_suite/tests/expand/generic_struct.expanded.rs

@@ -4,7 +4,7 @@ pub struct GenericStruct<T> {
 }
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_GenericStruct: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -12,7 +12,10 @@ const _IMPL_SERIALIZE_FOR_GenericStruct: () = {
     where
         T: _serde::Serialize,
     {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -21,15 +24,15 @@ const _IMPL_SERIALIZE_FOR_GenericStruct: () = {
                 "GenericStruct",
                 false as usize + 1,
             ) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "x", &self.x) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             _serde::ser::SerializeStruct::end(__serde_state)
@@ -38,7 +41,7 @@ const _IMPL_SERIALIZE_FOR_GenericStruct: () = {
 };
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -46,7 +49,7 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
     where
         T: _serde::Deserialize<'de>,
     {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -60,47 +63,49 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        0u64 => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"field index 0 <= i < 1",
-                        )),
+                        0u64 => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        "x" => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        "x" => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        b"x" => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        b"x" => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -111,8 +116,8 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
             where
                 T: _serde::Deserialize<'de>,
             {
-                marker: _serde::export::PhantomData<GenericStruct<T>>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<GenericStruct<T>>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, T> _serde::de::Visitor<'de> for __Visitor<'de, T>
             where
@@ -121,64 +126,64 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                 type Value = GenericStruct<T>;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "struct GenericStruct")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "struct GenericStruct")
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
                     let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 0usize,
                                 &"struct GenericStruct with 1 element",
                             ));
                         }
                     };
-                    _serde::export::Ok(GenericStruct { x: __field0 })
+                    _serde::__private::Ok(GenericStruct { x: __field0 })
                 }
                 #[inline]
                 fn visit_map<__A>(
                     self,
                     mut __map: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::MapAccess<'de>,
                 {
-                    let mut __field0: _serde::export::Option<T> = _serde::export::None;
-                    while let _serde::export::Some(__key) =
+                    let mut __field0: _serde::__private::Option<T> = _serde::__private::None;
+                    while let _serde::__private::Some(__key) =
                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         }
                     {
                         match __key {
                             __Field::__field0 => {
-                                if _serde::export::Option::is_some(&__field0) {
-                                    return _serde::export::Err(
+                                if _serde::__private::Option::is_some(&__field0) {
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field("x"),
                                     );
                                 }
-                                __field0 = _serde::export::Some(
+                                __field0 = _serde::__private::Some(
                                     match _serde::de::MapAccess::next_value::<T>(&mut __map) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     },
                                 );
@@ -188,24 +193,26 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                                     _serde::de::IgnoredAny,
                                 >(&mut __map)
                                 {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                             }
                         }
                     }
                     let __field0 = match __field0 {
-                        _serde::export::Some(__field0) => __field0,
-                        _serde::export::None => match _serde::private::de::missing_field("x") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        _serde::__private::Some(__field0) => __field0,
+                        _serde::__private::None => {
+                            match _serde::__private::de::missing_field("x") {
+                                _serde::__private::Ok(__val) => __val,
+                                _serde::__private::Err(__err) => {
+                                    return _serde::__private::Err(__err);
+                                }
                             }
-                        },
+                        }
                     };
-                    _serde::export::Ok(GenericStruct { x: __field0 })
+                    _serde::__private::Ok(GenericStruct { x: __field0 })
                 }
             }
             const FIELDS: &'static [&'static str] = &["x"];
@@ -214,15 +221,15 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                 "GenericStruct",
                 FIELDS,
                 __Visitor {
-                    marker: _serde::export::PhantomData::<GenericStruct<T>>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<GenericStruct<T>>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }
         fn deserialize_in_place<__D>(
             __deserializer: __D,
             __place: &mut Self,
-        ) -> _serde::export::Result<(), __D::Error>
+        ) -> _serde::__private::Result<(), __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -236,47 +243,49 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        0u64 => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"field index 0 <= i < 1",
-                        )),
+                        0u64 => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        "x" => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        "x" => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        b"x" => _serde::export::Ok(__Field::__field0),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        b"x" => _serde::__private::Ok(__Field::__field0),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -288,7 +297,7 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                 T: _serde::Deserialize<'de>,
             {
                 place: &'place mut GenericStruct<T>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, 'place, T: 'place> _serde::de::Visitor<'de> for __Visitor<'de, 'place, T>
             where
@@ -297,65 +306,65 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                 type Value = ();
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "struct GenericStruct")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "struct GenericStruct")
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.x),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.x),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             0usize,
                             &"struct GenericStruct with 1 element",
                         ));
                     }
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
                 #[inline]
                 fn visit_map<__A>(
                     self,
                     mut __map: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::MapAccess<'de>,
                 {
                     let mut __field0: bool = false;
-                    while let _serde::export::Some(__key) =
+                    while let _serde::__private::Some(__key) =
                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         }
                     {
                         match __key {
                             __Field::__field0 => {
                                 if __field0 {
-                                    return _serde::export::Err(
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field("x"),
                                     );
                                 }
                                 match _serde::de::MapAccess::next_value_seed(
                                     &mut __map,
-                                    _serde::private::de::InPlaceSeed(&mut self.place.x),
+                                    _serde::__private::de::InPlaceSeed(&mut self.place.x),
                                 ) {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                                 __field0 = true;
@@ -365,23 +374,23 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                                     _serde::de::IgnoredAny,
                                 >(&mut __map)
                                 {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                             }
                         }
                     }
                     if !__field0 {
-                        self.place.x = match _serde::private::de::missing_field("x") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        self.place.x = match _serde::__private::de::missing_field("x") {
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         };
                     };
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
             }
             const FIELDS: &'static [&'static str] = &["x"];
@@ -391,7 +400,7 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
                 FIELDS,
                 __Visitor {
                     place: __place,
-                    lifetime: _serde::export::PhantomData,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }
@@ -400,7 +409,7 @@ const _IMPL_DESERIALIZE_FOR_GenericStruct: () = {
 pub struct GenericNewTypeStruct<T>(T);
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_GenericNewTypeStruct: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -408,7 +417,10 @@ const _IMPL_SERIALIZE_FOR_GenericNewTypeStruct: () = {
     where
         T: _serde::Serialize,
     {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -422,7 +434,7 @@ const _IMPL_SERIALIZE_FOR_GenericNewTypeStruct: () = {
 };
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -430,7 +442,7 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
     where
         T: _serde::Deserialize<'de>,
     {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -438,8 +450,8 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
             where
                 T: _serde::Deserialize<'de>,
             {
-                marker: _serde::export::PhantomData<GenericNewTypeStruct<T>>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<GenericNewTypeStruct<T>>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, T> _serde::de::Visitor<'de> for __Visitor<'de, T>
             where
@@ -448,9 +460,9 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
                 type Value = GenericNewTypeStruct<T>;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(
                         __formatter,
                         "tuple struct GenericNewTypeStruct",
                     )
@@ -459,57 +471,57 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
                 fn visit_newtype_struct<__E>(
                     self,
                     __e: __E,
-                ) -> _serde::export::Result<Self::Value, __E::Error>
+                ) -> _serde::__private::Result<Self::Value, __E::Error>
                 where
                     __E: _serde::Deserializer<'de>,
                 {
                     let __field0: T = match <T as _serde::Deserialize>::deserialize(__e) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
-                    _serde::export::Ok(GenericNewTypeStruct(__field0))
+                    _serde::__private::Ok(GenericNewTypeStruct(__field0))
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
                     let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 0usize,
                                 &"tuple struct GenericNewTypeStruct with 1 element",
                             ));
                         }
                     };
-                    _serde::export::Ok(GenericNewTypeStruct(__field0))
+                    _serde::__private::Ok(GenericNewTypeStruct(__field0))
                 }
             }
             _serde::Deserializer::deserialize_newtype_struct(
                 __deserializer,
                 "GenericNewTypeStruct",
                 __Visitor {
-                    marker: _serde::export::PhantomData::<GenericNewTypeStruct<T>>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<GenericNewTypeStruct<T>>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }
         fn deserialize_in_place<__D>(
             __deserializer: __D,
             __place: &mut Self,
-        ) -> _serde::export::Result<(), __D::Error>
+        ) -> _serde::__private::Result<(), __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -518,7 +530,7 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
                 T: _serde::Deserialize<'de>,
             {
                 place: &'place mut GenericNewTypeStruct<T>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, 'place, T: 'place> _serde::de::Visitor<'de> for __Visitor<'de, 'place, T>
             where
@@ -527,9 +539,9 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
                 type Value = ();
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(
                         __formatter,
                         "tuple struct GenericNewTypeStruct",
                     )
@@ -538,7 +550,7 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
                 fn visit_newtype_struct<__E>(
                     self,
                     __e: __E,
-                ) -> _serde::export::Result<Self::Value, __E::Error>
+                ) -> _serde::__private::Result<Self::Value, __E::Error>
                 where
                     __E: _serde::Deserializer<'de>,
                 {
@@ -548,25 +560,25 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.0),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.0),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             0usize,
                             &"tuple struct GenericNewTypeStruct with 1 element",
                         ));
                     }
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
             }
             _serde::Deserializer::deserialize_newtype_struct(
@@ -574,7 +586,7 @@ const _IMPL_DESERIALIZE_FOR_GenericNewTypeStruct: () = {
                 "GenericNewTypeStruct",
                 __Visitor {
                     place: __place,
-                    lifetime: _serde::export::PhantomData,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }

test_suite/tests/expand/generic_tuple_struct.expanded.rs

@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 pub struct GenericTupleStruct<T, U>(T, U);
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -11,7 +11,7 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
         T: _serde::Deserialize<'de>,
         U: _serde::Deserialize<'de>,
     {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -20,8 +20,8 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                 T: _serde::Deserialize<'de>,
                 U: _serde::Deserialize<'de>,
             {
-                marker: _serde::export::PhantomData<GenericTupleStruct<T, U>>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<GenericTupleStruct<T, U>>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, T, U> _serde::de::Visitor<'de> for __Visitor<'de, T, U>
             where
@@ -31,9 +31,9 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                 type Value = GenericTupleStruct<T, U>;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(
                         __formatter,
                         "tuple struct GenericTupleStruct",
                     )
@@ -42,20 +42,20 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
                     let __field0 = match match _serde::de::SeqAccess::next_element::<T>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 0usize,
                                 &"tuple struct GenericTupleStruct with 2 elements",
                             ));
@@ -63,20 +63,20 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                     };
                     let __field1 = match match _serde::de::SeqAccess::next_element::<U>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 1usize,
                                 &"tuple struct GenericTupleStruct with 2 elements",
                             ));
                         }
                     };
-                    _serde::export::Ok(GenericTupleStruct(__field0, __field1))
+                    _serde::__private::Ok(GenericTupleStruct(__field0, __field1))
                 }
             }
             _serde::Deserializer::deserialize_tuple_struct(
@@ -84,15 +84,15 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                 "GenericTupleStruct",
                 2usize,
                 __Visitor {
-                    marker: _serde::export::PhantomData::<GenericTupleStruct<T, U>>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<GenericTupleStruct<T, U>>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }
         fn deserialize_in_place<__D>(
             __deserializer: __D,
             __place: &mut Self,
-        ) -> _serde::export::Result<(), __D::Error>
+        ) -> _serde::__private::Result<(), __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -102,7 +102,7 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                 U: _serde::Deserialize<'de>,
             {
                 place: &'place mut GenericTupleStruct<T, U>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, 'place, T: 'place, U: 'place> _serde::de::Visitor<'de> for __Visitor<'de, 'place, T, U>
             where
@@ -112,9 +112,9 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                 type Value = ();
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(
                         __formatter,
                         "tuple struct GenericTupleStruct",
                     )
@@ -123,39 +123,39 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.0),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.0),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             0usize,
                             &"tuple struct GenericTupleStruct with 2 elements",
                         ));
                     }
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.1),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.1),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             1usize,
                             &"tuple struct GenericTupleStruct with 2 elements",
                         ));
                     }
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
             }
             _serde::Deserializer::deserialize_tuple_struct(
@@ -164,7 +164,7 @@ const _IMPL_DESERIALIZE_FOR_GenericTupleStruct: () = {
                 2usize,
                 __Visitor {
                     place: __place,
-                    lifetime: _serde::export::PhantomData,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }

test_suite/tests/expand/lifetimes.expanded.rs

@@ -7,12 +7,15 @@ enum Lifetimes<'a> {
 }
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_Lifetimes: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
     impl<'a> _serde::Serialize for Lifetimes<'a> {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -43,9 +46,9 @@ const _IMPL_SERIALIZE_FOR_Lifetimes: () = {
                         "LifetimeMap",
                         0 + 1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -53,9 +56,9 @@ const _IMPL_SERIALIZE_FOR_Lifetimes: () = {
                         "a",
                         a,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     _serde::ser::SerializeStructVariant::end(__serde_state)
@@ -68,9 +71,9 @@ const _IMPL_SERIALIZE_FOR_Lifetimes: () = {
                         "NoLifetimeMap",
                         0 + 1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -78,9 +81,9 @@ const _IMPL_SERIALIZE_FOR_Lifetimes: () = {
                         "a",
                         a,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     _serde::ser::SerializeStructVariant::end(__serde_state)
@@ -91,12 +94,12 @@ const _IMPL_SERIALIZE_FOR_Lifetimes: () = {
 };
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
     impl<'de, 'a> _serde::Deserialize<'de> for Lifetimes<'a> {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -112,35 +115,38 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "variant identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "variant identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        0u64 => _serde::export::Ok(__Field::__field0),
-                        1u64 => _serde::export::Ok(__Field::__field1),
-                        2u64 => _serde::export::Ok(__Field::__field2),
-                        3u64 => _serde::export::Ok(__Field::__field3),
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                        0u64 => _serde::__private::Ok(__Field::__field0),
+                        1u64 => _serde::__private::Ok(__Field::__field1),
+                        2u64 => _serde::__private::Ok(__Field::__field2),
+                        3u64 => _serde::__private::Ok(__Field::__field3),
+                        _ => _serde::__private::Err(_serde::de::Error::invalid_value(
                             _serde::de::Unexpected::Unsigned(__value),
                             &"variant index 0 <= i < 4",
                         )),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        "LifetimeSeq" => _serde::export::Ok(__Field::__field0),
-                        "NoLifetimeSeq" => _serde::export::Ok(__Field::__field1),
-                        "LifetimeMap" => _serde::export::Ok(__Field::__field2),
-                        "NoLifetimeMap" => _serde::export::Ok(__Field::__field3),
-                        _ => _serde::export::Err(_serde::de::Error::unknown_variant(
+                        "LifetimeSeq" => _serde::__private::Ok(__Field::__field0),
+                        "NoLifetimeSeq" => _serde::__private::Ok(__Field::__field1),
+                        "LifetimeMap" => _serde::__private::Ok(__Field::__field2),
+                        "NoLifetimeMap" => _serde::__private::Ok(__Field::__field3),
+                        _ => _serde::__private::Err(_serde::de::Error::unknown_variant(
                             __value, VARIANTS,
                         )),
                     }
@@ -148,18 +154,18 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        b"LifetimeSeq" => _serde::export::Ok(__Field::__field0),
-                        b"NoLifetimeSeq" => _serde::export::Ok(__Field::__field1),
-                        b"LifetimeMap" => _serde::export::Ok(__Field::__field2),
-                        b"NoLifetimeMap" => _serde::export::Ok(__Field::__field3),
+                        b"LifetimeSeq" => _serde::__private::Ok(__Field::__field0),
+                        b"NoLifetimeSeq" => _serde::__private::Ok(__Field::__field1),
+                        b"LifetimeMap" => _serde::__private::Ok(__Field::__field2),
+                        b"NoLifetimeMap" => _serde::__private::Ok(__Field::__field3),
                         _ => {
-                            let __value = &_serde::export::from_utf8_lossy(__value);
-                            _serde::export::Err(_serde::de::Error::unknown_variant(
+                            let __value = &_serde::__private::from_utf8_lossy(__value);
+                            _serde::__private::Err(_serde::de::Error::unknown_variant(
                                 __value, VARIANTS,
                             ))
                         }
@@ -168,7 +174,9 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -176,35 +184,35 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                 }
             }
             struct __Visitor<'de, 'a> {
-                marker: _serde::export::PhantomData<Lifetimes<'a>>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<Lifetimes<'a>>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
                 type Value = Lifetimes<'a>;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "enum Lifetimes")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "enum Lifetimes")
                 }
                 fn visit_enum<__A>(
                     self,
                     __data: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::EnumAccess<'de>,
                 {
                     match match _serde::de::EnumAccess::variant(__data) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        (__Field::__field0, __variant) => _serde::export::Result::map(
+                        (__Field::__field0, __variant) => _serde::__private::Result::map(
                             _serde::de::VariantAccess::newtype_variant::<&'a i32>(__variant),
                             Lifetimes::LifetimeSeq,
                         ),
-                        (__Field::__field1, __variant) => _serde::export::Result::map(
+                        (__Field::__field1, __variant) => _serde::__private::Result::map(
                             _serde::de::VariantAccess::newtype_variant::<i32>(__variant),
                             Lifetimes::NoLifetimeSeq,
                         ),
@@ -219,9 +227,10 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 type Value = __Field;
                                 fn expecting(
                                     &self,
-                                    __formatter: &mut _serde::export::Formatter,
-                                ) -> _serde::export::fmt::Result {
-                                    _serde::export::Formatter::write_str(
+                                    __formatter: &mut _serde::__private::Formatter,
+                                ) -> _serde::__private::fmt::Result
+                                {
+                                    _serde::__private::Formatter::write_str(
                                         __formatter,
                                         "field identifier",
                                     )
@@ -229,40 +238,37 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 fn visit_u64<__E>(
                                     self,
                                     __value: u64,
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        0u64 => _serde::export::Ok(__Field::__field0),
-                                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                                            _serde::de::Unexpected::Unsigned(__value),
-                                            &"field index 0 <= i < 1",
-                                        )),
+                                        0u64 => _serde::__private::Ok(__Field::__field0),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                                 fn visit_str<__E>(
                                     self,
                                     __value: &str,
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        "a" => _serde::export::Ok(__Field::__field0),
-                                        _ => _serde::export::Ok(__Field::__ignore),
+                                        "a" => _serde::__private::Ok(__Field::__field0),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                                 fn visit_bytes<__E>(
                                     self,
                                     __value: &[u8],
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        b"a" => _serde::export::Ok(__Field::__field0),
-                                        _ => _serde::export::Ok(__Field::__ignore),
+                                        b"a" => _serde::__private::Ok(__Field::__field0),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                             }
@@ -270,7 +276,7 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 #[inline]
                                 fn deserialize<__D>(
                                     __deserializer: __D,
-                                ) -> _serde::export::Result<Self, __D::Error>
+                                ) -> _serde::__private::Result<Self, __D::Error>
                                 where
                                     __D: _serde::Deserializer<'de>,
                                 {
@@ -281,16 +287,17 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 }
                             }
                             struct __Visitor<'de, 'a> {
-                                marker: _serde::export::PhantomData<Lifetimes<'a>>,
-                                lifetime: _serde::export::PhantomData<&'de ()>,
+                                marker: _serde::__private::PhantomData<Lifetimes<'a>>,
+                                lifetime: _serde::__private::PhantomData<&'de ()>,
                             }
                             impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
                                 type Value = Lifetimes<'a>;
                                 fn expecting(
                                     &self,
-                                    __formatter: &mut _serde::export::Formatter,
-                                ) -> _serde::export::fmt::Result {
-                                    _serde::export::Formatter::write_str(
+                                    __formatter: &mut _serde::__private::Formatter,
+                                ) -> _serde::__private::fmt::Result
+                                {
+                                    _serde::__private::Formatter::write_str(
                                         __formatter,
                                         "struct variant Lifetimes::LifetimeMap",
                                     )
@@ -299,7 +306,7 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 fn visit_seq<__A>(
                                     self,
                                     mut __seq: __A,
-                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                ) -> _serde::__private::Result<Self::Value, __A::Error>
                                 where
                                     __A: _serde::de::SeqAccess<'de>,
                                 {
@@ -308,49 +315,49 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                     >(
                                         &mut __seq
                                     ) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     } {
-                                        _serde::export::Some(__value) => __value,
-                                        _serde::export::None => {
-                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 0usize , & "struct variant Lifetimes::LifetimeMap with 1 element" ) ) ;
+                                        _serde::__private::Some(__value) => __value,
+                                        _serde::__private::None => {
+                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (0usize , & "struct variant Lifetimes::LifetimeMap with 1 element")) ;
                                         }
                                     };
-                                    _serde::export::Ok(Lifetimes::LifetimeMap { a: __field0 })
+                                    _serde::__private::Ok(Lifetimes::LifetimeMap { a: __field0 })
                                 }
                                 #[inline]
                                 fn visit_map<__A>(
                                     self,
                                     mut __map: __A,
-                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                ) -> _serde::__private::Result<Self::Value, __A::Error>
                                 where
                                     __A: _serde::de::MapAccess<'de>,
                                 {
-                                    let mut __field0: _serde::export::Option<&'a i32> =
-                                        _serde::export::None;
-                                    while let _serde::export::Some(__key) =
+                                    let mut __field0: _serde::__private::Option<&'a i32> =
+                                        _serde::__private::None;
+                                    while let _serde::__private::Some(__key) =
                                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
                                         {
-                                            _serde::export::Ok(__val) => __val,
-                                            _serde::export::Err(__err) => {
-                                                return _serde::export::Err(__err);
+                                            _serde::__private::Ok(__val) => __val,
+                                            _serde::__private::Err(__err) => {
+                                                return _serde::__private::Err(__err);
                                             }
                                         }
                                     {
                                         match __key {
                                             __Field::__field0 => {
-                                                if _serde::export::Option::is_some(&__field0) {
-                                                    return _serde :: export :: Err ( < __A :: Error as _serde :: de :: Error > :: duplicate_field ( "a" ) ) ;
+                                                if _serde::__private::Option::is_some(&__field0) {
+                                                    return _serde :: __private :: Err (< __A :: Error as _serde :: de :: Error > :: duplicate_field ("a")) ;
                                                 }
-                                                __field0 = _serde::export::Some(
+                                                __field0 = _serde::__private::Some(
                                                     match _serde::de::MapAccess::next_value::<&'a i32>(
                                                         &mut __map,
                                                     ) {
-                                                        _serde::export::Ok(__val) => __val,
-                                                        _serde::export::Err(__err) => {
-                                                            return _serde::export::Err(__err);
+                                                        _serde::__private::Ok(__val) => __val,
+                                                        _serde::__private::Err(__err) => {
+                                                            return _serde::__private::Err(__err);
                                                         }
                                                     },
                                                 );
@@ -361,26 +368,26 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                                 >(
                                                     &mut __map
                                                 ) {
-                                                    _serde::export::Ok(__val) => __val,
-                                                    _serde::export::Err(__err) => {
-                                                        return _serde::export::Err(__err);
+                                                    _serde::__private::Ok(__val) => __val,
+                                                    _serde::__private::Err(__err) => {
+                                                        return _serde::__private::Err(__err);
                                                     }
                                                 };
                                             }
                                         }
                                     }
                                     let __field0 = match __field0 {
-                                        _serde::export::Some(__field0) => __field0,
-                                        _serde::export::None => {
-                                            match _serde::private::de::missing_field("a") {
-                                                _serde::export::Ok(__val) => __val,
-                                                _serde::export::Err(__err) => {
-                                                    return _serde::export::Err(__err);
+                                        _serde::__private::Some(__field0) => __field0,
+                                        _serde::__private::None => {
+                                            match _serde::__private::de::missing_field("a") {
+                                                _serde::__private::Ok(__val) => __val,
+                                                _serde::__private::Err(__err) => {
+                                                    return _serde::__private::Err(__err);
                                                 }
                                             }
                                         }
                                     };
-                                    _serde::export::Ok(Lifetimes::LifetimeMap { a: __field0 })
+                                    _serde::__private::Ok(Lifetimes::LifetimeMap { a: __field0 })
                                 }
                             }
                             const FIELDS: &'static [&'static str] = &["a"];
@@ -388,8 +395,8 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 __variant,
                                 FIELDS,
                                 __Visitor {
-                                    marker: _serde::export::PhantomData::<Lifetimes<'a>>,
-                                    lifetime: _serde::export::PhantomData,
+                                    marker: _serde::__private::PhantomData::<Lifetimes<'a>>,
+                                    lifetime: _serde::__private::PhantomData,
                                 },
                             )
                         }
@@ -404,9 +411,10 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 type Value = __Field;
                                 fn expecting(
                                     &self,
-                                    __formatter: &mut _serde::export::Formatter,
-                                ) -> _serde::export::fmt::Result {
-                                    _serde::export::Formatter::write_str(
+                                    __formatter: &mut _serde::__private::Formatter,
+                                ) -> _serde::__private::fmt::Result
+                                {
+                                    _serde::__private::Formatter::write_str(
                                         __formatter,
                                         "field identifier",
                                     )
@@ -414,40 +422,37 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 fn visit_u64<__E>(
                                     self,
                                     __value: u64,
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        0u64 => _serde::export::Ok(__Field::__field0),
-                                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                                            _serde::de::Unexpected::Unsigned(__value),
-                                            &"field index 0 <= i < 1",
-                                        )),
+                                        0u64 => _serde::__private::Ok(__Field::__field0),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                                 fn visit_str<__E>(
                                     self,
                                     __value: &str,
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        "a" => _serde::export::Ok(__Field::__field0),
-                                        _ => _serde::export::Ok(__Field::__ignore),
+                                        "a" => _serde::__private::Ok(__Field::__field0),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                                 fn visit_bytes<__E>(
                                     self,
                                     __value: &[u8],
-                                ) -> _serde::export::Result<Self::Value, __E>
+                                ) -> _serde::__private::Result<Self::Value, __E>
                                 where
                                     __E: _serde::de::Error,
                                 {
                                     match __value {
-                                        b"a" => _serde::export::Ok(__Field::__field0),
-                                        _ => _serde::export::Ok(__Field::__ignore),
+                                        b"a" => _serde::__private::Ok(__Field::__field0),
+                                        _ => _serde::__private::Ok(__Field::__ignore),
                                     }
                                 }
                             }
@@ -455,7 +460,7 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 #[inline]
                                 fn deserialize<__D>(
                                     __deserializer: __D,
-                                ) -> _serde::export::Result<Self, __D::Error>
+                                ) -> _serde::__private::Result<Self, __D::Error>
                                 where
                                     __D: _serde::Deserializer<'de>,
                                 {
@@ -466,16 +471,17 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 }
                             }
                             struct __Visitor<'de, 'a> {
-                                marker: _serde::export::PhantomData<Lifetimes<'a>>,
-                                lifetime: _serde::export::PhantomData<&'de ()>,
+                                marker: _serde::__private::PhantomData<Lifetimes<'a>>,
+                                lifetime: _serde::__private::PhantomData<&'de ()>,
                             }
                             impl<'de, 'a> _serde::de::Visitor<'de> for __Visitor<'de, 'a> {
                                 type Value = Lifetimes<'a>;
                                 fn expecting(
                                     &self,
-                                    __formatter: &mut _serde::export::Formatter,
-                                ) -> _serde::export::fmt::Result {
-                                    _serde::export::Formatter::write_str(
+                                    __formatter: &mut _serde::__private::Formatter,
+                                ) -> _serde::__private::fmt::Result
+                                {
+                                    _serde::__private::Formatter::write_str(
                                         __formatter,
                                         "struct variant Lifetimes::NoLifetimeMap",
                                     )
@@ -484,7 +490,7 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 fn visit_seq<__A>(
                                     self,
                                     mut __seq: __A,
-                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                ) -> _serde::__private::Result<Self::Value, __A::Error>
                                 where
                                     __A: _serde::de::SeqAccess<'de>,
                                 {
@@ -493,49 +499,49 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                     >(
                                         &mut __seq
                                     ) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     } {
-                                        _serde::export::Some(__value) => __value,
-                                        _serde::export::None => {
-                                            return _serde :: export :: Err ( _serde :: de :: Error :: invalid_length ( 0usize , & "struct variant Lifetimes::NoLifetimeMap with 1 element" ) ) ;
+                                        _serde::__private::Some(__value) => __value,
+                                        _serde::__private::None => {
+                                            return _serde :: __private :: Err (_serde :: de :: Error :: invalid_length (0usize , & "struct variant Lifetimes::NoLifetimeMap with 1 element")) ;
                                         }
                                     };
-                                    _serde::export::Ok(Lifetimes::NoLifetimeMap { a: __field0 })
+                                    _serde::__private::Ok(Lifetimes::NoLifetimeMap { a: __field0 })
                                 }
                                 #[inline]
                                 fn visit_map<__A>(
                                     self,
                                     mut __map: __A,
-                                ) -> _serde::export::Result<Self::Value, __A::Error>
+                                ) -> _serde::__private::Result<Self::Value, __A::Error>
                                 where
                                     __A: _serde::de::MapAccess<'de>,
                                 {
-                                    let mut __field0: _serde::export::Option<i32> =
-                                        _serde::export::None;
-                                    while let _serde::export::Some(__key) =
+                                    let mut __field0: _serde::__private::Option<i32> =
+                                        _serde::__private::None;
+                                    while let _serde::__private::Some(__key) =
                                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map)
                                         {
-                                            _serde::export::Ok(__val) => __val,
-                                            _serde::export::Err(__err) => {
-                                                return _serde::export::Err(__err);
+                                            _serde::__private::Ok(__val) => __val,
+                                            _serde::__private::Err(__err) => {
+                                                return _serde::__private::Err(__err);
                                             }
                                         }
                                     {
                                         match __key {
                                             __Field::__field0 => {
-                                                if _serde::export::Option::is_some(&__field0) {
-                                                    return _serde :: export :: Err ( < __A :: Error as _serde :: de :: Error > :: duplicate_field ( "a" ) ) ;
+                                                if _serde::__private::Option::is_some(&__field0) {
+                                                    return _serde :: __private :: Err (< __A :: Error as _serde :: de :: Error > :: duplicate_field ("a")) ;
                                                 }
-                                                __field0 = _serde::export::Some(
+                                                __field0 = _serde::__private::Some(
                                                     match _serde::de::MapAccess::next_value::<i32>(
                                                         &mut __map,
                                                     ) {
-                                                        _serde::export::Ok(__val) => __val,
-                                                        _serde::export::Err(__err) => {
-                                                            return _serde::export::Err(__err);
+                                                        _serde::__private::Ok(__val) => __val,
+                                                        _serde::__private::Err(__err) => {
+                                                            return _serde::__private::Err(__err);
                                                         }
                                                     },
                                                 );
@@ -546,26 +552,26 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                                 >(
                                                     &mut __map
                                                 ) {
-                                                    _serde::export::Ok(__val) => __val,
-                                                    _serde::export::Err(__err) => {
-                                                        return _serde::export::Err(__err);
+                                                    _serde::__private::Ok(__val) => __val,
+                                                    _serde::__private::Err(__err) => {
+                                                        return _serde::__private::Err(__err);
                                                     }
                                                 };
                                             }
                                         }
                                     }
                                     let __field0 = match __field0 {
-                                        _serde::export::Some(__field0) => __field0,
-                                        _serde::export::None => {
-                                            match _serde::private::de::missing_field("a") {
-                                                _serde::export::Ok(__val) => __val,
-                                                _serde::export::Err(__err) => {
-                                                    return _serde::export::Err(__err);
+                                        _serde::__private::Some(__field0) => __field0,
+                                        _serde::__private::None => {
+                                            match _serde::__private::de::missing_field("a") {
+                                                _serde::__private::Ok(__val) => __val,
+                                                _serde::__private::Err(__err) => {
+                                                    return _serde::__private::Err(__err);
                                                 }
                                             }
                                         }
                                     };
-                                    _serde::export::Ok(Lifetimes::NoLifetimeMap { a: __field0 })
+                                    _serde::__private::Ok(Lifetimes::NoLifetimeMap { a: __field0 })
                                 }
                             }
                             const FIELDS: &'static [&'static str] = &["a"];
@@ -573,8 +579,8 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                                 __variant,
                                 FIELDS,
                                 __Visitor {
-                                    marker: _serde::export::PhantomData::<Lifetimes<'a>>,
-                                    lifetime: _serde::export::PhantomData,
+                                    marker: _serde::__private::PhantomData::<Lifetimes<'a>>,
+                                    lifetime: _serde::__private::PhantomData,
                                 },
                             )
                         }
@@ -592,8 +598,8 @@ const _IMPL_DESERIALIZE_FOR_Lifetimes: () = {
                 "Lifetimes",
                 VARIANTS,
                 __Visitor {
-                    marker: _serde::export::PhantomData::<Lifetimes<'a>>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<Lifetimes<'a>>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }

test_suite/tests/expand/named_map.expanded.rs

@@ -6,7 +6,7 @@ struct SerNamedMap<'a, 'b, A: 'a, B: 'b, C> {
 }
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_SerNamedMap: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -16,7 +16,10 @@ const _IMPL_SERIALIZE_FOR_SerNamedMap: () = {
         B: _serde::Serialize,
         C: _serde::Serialize,
     {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -25,27 +28,27 @@ const _IMPL_SERIALIZE_FOR_SerNamedMap: () = {
                 "SerNamedMap",
                 false as usize + 1 + 1 + 1,
             ) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "a", &self.a) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "b", &self.b) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             match _serde::ser::SerializeStruct::serialize_field(&mut __serde_state, "c", &self.c) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             _serde::ser::SerializeStruct::end(__serde_state)
@@ -59,7 +62,7 @@ struct DeNamedMap<A, B, C> {
 }
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -69,7 +72,7 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
         B: _serde::Deserialize<'de>,
         C: _serde::Deserialize<'de>,
     {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -85,53 +88,55 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        0u64 => _serde::export::Ok(__Field::__field0),
-                        1u64 => _serde::export::Ok(__Field::__field1),
-                        2u64 => _serde::export::Ok(__Field::__field2),
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"field index 0 <= i < 3",
-                        )),
+                        0u64 => _serde::__private::Ok(__Field::__field0),
+                        1u64 => _serde::__private::Ok(__Field::__field1),
+                        2u64 => _serde::__private::Ok(__Field::__field2),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        "a" => _serde::export::Ok(__Field::__field0),
-                        "b" => _serde::export::Ok(__Field::__field1),
-                        "c" => _serde::export::Ok(__Field::__field2),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        "a" => _serde::__private::Ok(__Field::__field0),
+                        "b" => _serde::__private::Ok(__Field::__field1),
+                        "c" => _serde::__private::Ok(__Field::__field2),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        b"a" => _serde::export::Ok(__Field::__field0),
-                        b"b" => _serde::export::Ok(__Field::__field1),
-                        b"c" => _serde::export::Ok(__Field::__field2),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        b"a" => _serde::__private::Ok(__Field::__field0),
+                        b"b" => _serde::__private::Ok(__Field::__field1),
+                        b"c" => _serde::__private::Ok(__Field::__field2),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -144,8 +149,8 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 B: _serde::Deserialize<'de>,
                 C: _serde::Deserialize<'de>,
             {
-                marker: _serde::export::PhantomData<DeNamedMap<A, B, C>>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<DeNamedMap<A, B, C>>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, A, B, C> _serde::de::Visitor<'de> for __Visitor<'de, A, B, C>
             where
@@ -156,28 +161,28 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 type Value = DeNamedMap<A, B, C>;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "struct DeNamedMap")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "struct DeNamedMap")
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
                     let __field0 = match match _serde::de::SeqAccess::next_element::<A>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 0usize,
                                 &"struct DeNamedMap with 3 elements",
                             ));
@@ -185,14 +190,14 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                     };
                     let __field1 = match match _serde::de::SeqAccess::next_element::<B>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 1usize,
                                 &"struct DeNamedMap with 3 elements",
                             ));
@@ -200,20 +205,20 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                     };
                     let __field2 = match match _serde::de::SeqAccess::next_element::<C>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 2usize,
                                 &"struct DeNamedMap with 3 elements",
                             ));
                         }
                     };
-                    _serde::export::Ok(DeNamedMap {
+                    _serde::__private::Ok(DeNamedMap {
                         a: __field0,
                         b: __field1,
                         c: __field2,
@@ -223,63 +228,63 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 fn visit_map<__A>(
                     self,
                     mut __map: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::MapAccess<'de>,
                 {
-                    let mut __field0: _serde::export::Option<A> = _serde::export::None;
-                    let mut __field1: _serde::export::Option<B> = _serde::export::None;
-                    let mut __field2: _serde::export::Option<C> = _serde::export::None;
-                    while let _serde::export::Some(__key) =
+                    let mut __field0: _serde::__private::Option<A> = _serde::__private::None;
+                    let mut __field1: _serde::__private::Option<B> = _serde::__private::None;
+                    let mut __field2: _serde::__private::Option<C> = _serde::__private::None;
+                    while let _serde::__private::Some(__key) =
                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         }
                     {
                         match __key {
                             __Field::__field0 => {
-                                if _serde::export::Option::is_some(&__field0) {
-                                    return _serde::export::Err(
+                                if _serde::__private::Option::is_some(&__field0) {
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field("a"),
                                     );
                                 }
-                                __field0 = _serde::export::Some(
+                                __field0 = _serde::__private::Some(
                                     match _serde::de::MapAccess::next_value::<A>(&mut __map) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     },
                                 );
                             }
                             __Field::__field1 => {
-                                if _serde::export::Option::is_some(&__field1) {
-                                    return _serde::export::Err(
+                                if _serde::__private::Option::is_some(&__field1) {
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field("b"),
                                     );
                                 }
-                                __field1 = _serde::export::Some(
+                                __field1 = _serde::__private::Some(
                                     match _serde::de::MapAccess::next_value::<B>(&mut __map) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     },
                                 );
                             }
                             __Field::__field2 => {
-                                if _serde::export::Option::is_some(&__field2) {
-                                    return _serde::export::Err(
+                                if _serde::__private::Option::is_some(&__field2) {
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field("c"),
                                     );
                                 }
-                                __field2 = _serde::export::Some(
+                                __field2 = _serde::__private::Some(
                                     match _serde::de::MapAccess::next_value::<C>(&mut __map) {
-                                        _serde::export::Ok(__val) => __val,
-                                        _serde::export::Err(__err) => {
-                                            return _serde::export::Err(__err);
+                                        _serde::__private::Ok(__val) => __val,
+                                        _serde::__private::Err(__err) => {
+                                            return _serde::__private::Err(__err);
                                         }
                                     },
                                 );
@@ -289,42 +294,48 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                                     _serde::de::IgnoredAny,
                                 >(&mut __map)
                                 {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                             }
                         }
                     }
                     let __field0 = match __field0 {
-                        _serde::export::Some(__field0) => __field0,
-                        _serde::export::None => match _serde::private::de::missing_field("a") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        _serde::__private::Some(__field0) => __field0,
+                        _serde::__private::None => {
+                            match _serde::__private::de::missing_field("a") {
+                                _serde::__private::Ok(__val) => __val,
+                                _serde::__private::Err(__err) => {
+                                    return _serde::__private::Err(__err);
+                                }
                             }
-                        },
+                        }
                     };
                     let __field1 = match __field1 {
-                        _serde::export::Some(__field1) => __field1,
-                        _serde::export::None => match _serde::private::de::missing_field("b") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        _serde::__private::Some(__field1) => __field1,
+                        _serde::__private::None => {
+                            match _serde::__private::de::missing_field("b") {
+                                _serde::__private::Ok(__val) => __val,
+                                _serde::__private::Err(__err) => {
+                                    return _serde::__private::Err(__err);
+                                }
                             }
-                        },
+                        }
                     };
                     let __field2 = match __field2 {
-                        _serde::export::Some(__field2) => __field2,
-                        _serde::export::None => match _serde::private::de::missing_field("c") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        _serde::__private::Some(__field2) => __field2,
+                        _serde::__private::None => {
+                            match _serde::__private::de::missing_field("c") {
+                                _serde::__private::Ok(__val) => __val,
+                                _serde::__private::Err(__err) => {
+                                    return _serde::__private::Err(__err);
+                                }
                             }
-                        },
+                        }
                     };
-                    _serde::export::Ok(DeNamedMap {
+                    _serde::__private::Ok(DeNamedMap {
                         a: __field0,
                         b: __field1,
                         c: __field2,
@@ -337,15 +348,15 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 "DeNamedMap",
                 FIELDS,
                 __Visitor {
-                    marker: _serde::export::PhantomData::<DeNamedMap<A, B, C>>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<DeNamedMap<A, B, C>>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }
         fn deserialize_in_place<__D>(
             __deserializer: __D,
             __place: &mut Self,
-        ) -> _serde::export::Result<(), __D::Error>
+        ) -> _serde::__private::Result<(), __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -361,53 +372,55 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "field identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "field identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        0u64 => _serde::export::Ok(__Field::__field0),
-                        1u64 => _serde::export::Ok(__Field::__field1),
-                        2u64 => _serde::export::Ok(__Field::__field2),
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
-                            _serde::de::Unexpected::Unsigned(__value),
-                            &"field index 0 <= i < 3",
-                        )),
+                        0u64 => _serde::__private::Ok(__Field::__field0),
+                        1u64 => _serde::__private::Ok(__Field::__field1),
+                        2u64 => _serde::__private::Ok(__Field::__field2),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        "a" => _serde::export::Ok(__Field::__field0),
-                        "b" => _serde::export::Ok(__Field::__field1),
-                        "c" => _serde::export::Ok(__Field::__field2),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        "a" => _serde::__private::Ok(__Field::__field0),
+                        "b" => _serde::__private::Ok(__Field::__field1),
+                        "c" => _serde::__private::Ok(__Field::__field2),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        b"a" => _serde::export::Ok(__Field::__field0),
-                        b"b" => _serde::export::Ok(__Field::__field1),
-                        b"c" => _serde::export::Ok(__Field::__field2),
-                        _ => _serde::export::Ok(__Field::__ignore),
+                        b"a" => _serde::__private::Ok(__Field::__field0),
+                        b"b" => _serde::__private::Ok(__Field::__field1),
+                        b"c" => _serde::__private::Ok(__Field::__field2),
+                        _ => _serde::__private::Ok(__Field::__ignore),
                     }
                 }
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -421,7 +434,7 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 C: _serde::Deserialize<'de>,
             {
                 place: &'place mut DeNamedMap<A, B, C>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, 'place, A: 'place, B: 'place, C: 'place> _serde::de::Visitor<'de>
                 for __Visitor<'de, 'place, A, B, C>
@@ -433,129 +446,129 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 type Value = ();
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "struct DeNamedMap")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "struct DeNamedMap")
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.a),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.a),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             0usize,
                             &"struct DeNamedMap with 3 elements",
                         ));
                     }
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.b),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.b),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             1usize,
                             &"struct DeNamedMap with 3 elements",
                         ));
                     }
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.c),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.c),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             2usize,
                             &"struct DeNamedMap with 3 elements",
                         ));
                     }
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
                 #[inline]
                 fn visit_map<__A>(
                     self,
                     mut __map: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::MapAccess<'de>,
                 {
                     let mut __field0: bool = false;
                     let mut __field1: bool = false;
                     let mut __field2: bool = false;
-                    while let _serde::export::Some(__key) =
+                    while let _serde::__private::Some(__key) =
                         match _serde::de::MapAccess::next_key::<__Field>(&mut __map) {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         }
                     {
                         match __key {
                             __Field::__field0 => {
                                 if __field0 {
-                                    return _serde::export::Err(
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field("a"),
                                     );
                                 }
                                 match _serde::de::MapAccess::next_value_seed(
                                     &mut __map,
-                                    _serde::private::de::InPlaceSeed(&mut self.place.a),
+                                    _serde::__private::de::InPlaceSeed(&mut self.place.a),
                                 ) {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                                 __field0 = true;
                             }
                             __Field::__field1 => {
                                 if __field1 {
-                                    return _serde::export::Err(
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field("b"),
                                     );
                                 }
                                 match _serde::de::MapAccess::next_value_seed(
                                     &mut __map,
-                                    _serde::private::de::InPlaceSeed(&mut self.place.b),
+                                    _serde::__private::de::InPlaceSeed(&mut self.place.b),
                                 ) {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                                 __field1 = true;
                             }
                             __Field::__field2 => {
                                 if __field2 {
-                                    return _serde::export::Err(
+                                    return _serde::__private::Err(
                                         <__A::Error as _serde::de::Error>::duplicate_field("c"),
                                     );
                                 }
                                 match _serde::de::MapAccess::next_value_seed(
                                     &mut __map,
-                                    _serde::private::de::InPlaceSeed(&mut self.place.c),
+                                    _serde::__private::de::InPlaceSeed(&mut self.place.c),
                                 ) {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                                 __field2 = true;
@@ -565,39 +578,39 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                                     _serde::de::IgnoredAny,
                                 >(&mut __map)
                                 {
-                                    _serde::export::Ok(__val) => __val,
-                                    _serde::export::Err(__err) => {
-                                        return _serde::export::Err(__err);
+                                    _serde::__private::Ok(__val) => __val,
+                                    _serde::__private::Err(__err) => {
+                                        return _serde::__private::Err(__err);
                                     }
                                 };
                             }
                         }
                     }
                     if !__field0 {
-                        self.place.a = match _serde::private::de::missing_field("a") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        self.place.a = match _serde::__private::de::missing_field("a") {
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         };
                     };
                     if !__field1 {
-                        self.place.b = match _serde::private::de::missing_field("b") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        self.place.b = match _serde::__private::de::missing_field("b") {
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         };
                     };
                     if !__field2 {
-                        self.place.c = match _serde::private::de::missing_field("c") {
-                            _serde::export::Ok(__val) => __val,
-                            _serde::export::Err(__err) => {
-                                return _serde::export::Err(__err);
+                        self.place.c = match _serde::__private::de::missing_field("c") {
+                            _serde::__private::Ok(__val) => __val,
+                            _serde::__private::Err(__err) => {
+                                return _serde::__private::Err(__err);
                             }
                         };
                     };
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
             }
             const FIELDS: &'static [&'static str] = &["a", "b", "c"];
@@ -607,7 +620,7 @@ const _IMPL_DESERIALIZE_FOR_DeNamedMap: () = {
                 FIELDS,
                 __Visitor {
                     place: __place,
-                    lifetime: _serde::export::PhantomData,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }

test_suite/tests/expand/named_tuple.expanded.rs

@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 struct SerNamedTuple<'a, 'b, A: 'a, B: 'b, C>(&'a A, &'b mut B, C);
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_SerNamedTuple: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -12,7 +12,10 @@ const _IMPL_SERIALIZE_FOR_SerNamedTuple: () = {
         B: _serde::Serialize,
         C: _serde::Serialize,
     {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -21,27 +24,27 @@ const _IMPL_SERIALIZE_FOR_SerNamedTuple: () = {
                 "SerNamedTuple",
                 0 + 1 + 1 + 1,
             ) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.0) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.1) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             match _serde::ser::SerializeTupleStruct::serialize_field(&mut __serde_state, &self.2) {
-                _serde::export::Ok(__val) => __val,
-                _serde::export::Err(__err) => {
-                    return _serde::export::Err(__err);
+                _serde::__private::Ok(__val) => __val,
+                _serde::__private::Err(__err) => {
+                    return _serde::__private::Err(__err);
                 }
             };
             _serde::ser::SerializeTupleStruct::end(__serde_state)
@@ -51,7 +54,7 @@ const _IMPL_SERIALIZE_FOR_SerNamedTuple: () = {
 struct DeNamedTuple<A, B, C>(A, B, C);
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -61,7 +64,7 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
         B: _serde::Deserialize<'de>,
         C: _serde::Deserialize<'de>,
     {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -71,8 +74,8 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
                 B: _serde::Deserialize<'de>,
                 C: _serde::Deserialize<'de>,
             {
-                marker: _serde::export::PhantomData<DeNamedTuple<A, B, C>>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<DeNamedTuple<A, B, C>>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, A, B, C> _serde::de::Visitor<'de> for __Visitor<'de, A, B, C>
             where
@@ -83,28 +86,31 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
                 type Value = DeNamedTuple<A, B, C>;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "tuple struct DeNamedTuple")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(
+                        __formatter,
+                        "tuple struct DeNamedTuple",
+                    )
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
                     let __field0 = match match _serde::de::SeqAccess::next_element::<A>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 0usize,
                                 &"tuple struct DeNamedTuple with 3 elements",
                             ));
@@ -112,14 +118,14 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
                     };
                     let __field1 = match match _serde::de::SeqAccess::next_element::<B>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 1usize,
                                 &"tuple struct DeNamedTuple with 3 elements",
                             ));
@@ -127,20 +133,20 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
                     };
                     let __field2 = match match _serde::de::SeqAccess::next_element::<C>(&mut __seq)
                     {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        _serde::export::Some(__value) => __value,
-                        _serde::export::None => {
-                            return _serde::export::Err(_serde::de::Error::invalid_length(
+                        _serde::__private::Some(__value) => __value,
+                        _serde::__private::None => {
+                            return _serde::__private::Err(_serde::de::Error::invalid_length(
                                 2usize,
                                 &"tuple struct DeNamedTuple with 3 elements",
                             ));
                         }
                     };
-                    _serde::export::Ok(DeNamedTuple(__field0, __field1, __field2))
+                    _serde::__private::Ok(DeNamedTuple(__field0, __field1, __field2))
                 }
             }
             _serde::Deserializer::deserialize_tuple_struct(
@@ -148,15 +154,15 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
                 "DeNamedTuple",
                 3usize,
                 __Visitor {
-                    marker: _serde::export::PhantomData::<DeNamedTuple<A, B, C>>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<DeNamedTuple<A, B, C>>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }
         fn deserialize_in_place<__D>(
             __deserializer: __D,
             __place: &mut Self,
-        ) -> _serde::export::Result<(), __D::Error>
+        ) -> _serde::__private::Result<(), __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -167,7 +173,7 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
                 C: _serde::Deserialize<'de>,
             {
                 place: &'place mut DeNamedTuple<A, B, C>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de, 'place, A: 'place, B: 'place, C: 'place> _serde::de::Visitor<'de>
                 for __Visitor<'de, 'place, A, B, C>
@@ -179,61 +185,64 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
                 type Value = ();
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "tuple struct DeNamedTuple")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(
+                        __formatter,
+                        "tuple struct DeNamedTuple",
+                    )
                 }
                 #[inline]
                 fn visit_seq<__A>(
                     self,
                     mut __seq: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::SeqAccess<'de>,
                 {
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.0),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.0),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             0usize,
                             &"tuple struct DeNamedTuple with 3 elements",
                         ));
                     }
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.1),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.1),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             1usize,
                             &"tuple struct DeNamedTuple with 3 elements",
                         ));
                     }
-                    if let _serde::export::None = match _serde::de::SeqAccess::next_element_seed(
+                    if let _serde::__private::None = match _serde::de::SeqAccess::next_element_seed(
                         &mut __seq,
-                        _serde::private::de::InPlaceSeed(&mut self.place.2),
+                        _serde::__private::de::InPlaceSeed(&mut self.place.2),
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     } {
-                        return _serde::export::Err(_serde::de::Error::invalid_length(
+                        return _serde::__private::Err(_serde::de::Error::invalid_length(
                             2usize,
                             &"tuple struct DeNamedTuple with 3 elements",
                         ));
                     }
-                    _serde::export::Ok(())
+                    _serde::__private::Ok(())
                 }
             }
             _serde::Deserializer::deserialize_tuple_struct(
@@ -242,7 +251,7 @@ const _IMPL_DESERIALIZE_FOR_DeNamedTuple: () = {
                 3usize,
                 __Visitor {
                     place: __place,
-                    lifetime: _serde::export::PhantomData,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }

test_suite/tests/expand/named_unit.expanded.rs

@@ -2,12 +2,15 @@ use serde::{Deserialize, Serialize};
 struct NamedUnit;
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_NamedUnit: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
     impl _serde::Serialize for NamedUnit {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -17,12 +20,12 @@ const _IMPL_SERIALIZE_FOR_NamedUnit: () = {
 };
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_NamedUnit: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
     impl<'de> _serde::Deserialize<'de> for NamedUnit {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -31,16 +34,16 @@ const _IMPL_DESERIALIZE_FOR_NamedUnit: () = {
                 type Value = NamedUnit;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "unit struct NamedUnit")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "unit struct NamedUnit")
                 }
                 #[inline]
-                fn visit_unit<__E>(self) -> _serde::export::Result<Self::Value, __E>
+                fn visit_unit<__E>(self) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
-                    _serde::export::Ok(NamedUnit)
+                    _serde::__private::Ok(NamedUnit)
                 }
             }
             _serde::Deserializer::deserialize_unit_struct(__deserializer, "NamedUnit", __Visitor)

test_suite/tests/expand/ser_enum.expanded.rs

@@ -12,7 +12,7 @@ where
 }
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_SerEnum: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -23,7 +23,10 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
         C: _serde::Serialize,
         D: _serde::Serialize,
     {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -42,45 +45,45 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "Seq",
                         0 + 1 + 1 + 1 + 1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field0,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field2,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field3,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     _serde::ser::SerializeTupleVariant::end(__serde_state)
@@ -98,9 +101,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "Map",
                         0 + 1 + 1 + 1 + 1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -108,9 +111,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "a",
                         a,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -118,9 +121,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "b",
                         b,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -128,9 +131,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "c",
                         c,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -138,9 +141,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "d",
                         d,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     _serde::ser::SerializeStructVariant::end(__serde_state)
@@ -159,45 +162,45 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "_Seq2",
                         0 + 1 + 1 + 1 + 1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field0,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field2,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeTupleVariant::serialize_field(
                         &mut __serde_state,
                         __field3,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     _serde::ser::SerializeTupleVariant::end(__serde_state)
@@ -215,9 +218,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "_Map2",
                         0 + 1 + 1 + 1 + 1,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -225,9 +228,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "a",
                         a,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -235,9 +238,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "b",
                         b,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -245,9 +248,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "c",
                         c,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     match _serde::ser::SerializeStructVariant::serialize_field(
@@ -255,9 +258,9 @@ const _IMPL_SERIALIZE_FOR_SerEnum: () = {
                         "d",
                         d,
                     ) {
-                        _serde::export::Ok(__val) => __val,
-                        _serde::export::Err(__err) => {
-                            return _serde::export::Err(__err);
+                        _serde::__private::Ok(__val) => __val,
+                        _serde::__private::Err(__err) => {
+                            return _serde::__private::Err(__err);
                         }
                     };
                     _serde::ser::SerializeStructVariant::end(__serde_state)

test_suite/tests/expand/void.expanded.rs

@@ -2,12 +2,15 @@ use serde::{Deserialize, Serialize};
 enum Void {}
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_Void: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
     impl _serde::Serialize for Void {
-        fn serialize<__S>(&self, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+        fn serialize<__S>(
+            &self,
+            __serializer: __S,
+        ) -> _serde::__private::Result<__S::Ok, __S::Error>
         where
             __S: _serde::Serializer,
         {
@@ -17,12 +20,12 @@ const _IMPL_SERIALIZE_FOR_Void: () = {
 };
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_Void: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
     impl<'de> _serde::Deserialize<'de> for Void {
-        fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+        fn deserialize<__D>(__deserializer: __D) -> _serde::__private::Result<Self, __D::Error>
         where
             __D: _serde::Deserializer<'de>,
         {
@@ -33,27 +36,30 @@ const _IMPL_DESERIALIZE_FOR_Void: () = {
                 type Value = __Field;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "variant identifier")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "variant identifier")
                 }
-                fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
+                fn visit_u64<__E>(self, __value: u64) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        _ => _serde::export::Err(_serde::de::Error::invalid_value(
+                        _ => _serde::__private::Err(_serde::de::Error::invalid_value(
                             _serde::de::Unexpected::Unsigned(__value),
                             &"variant index 0 <= i < 0",
                         )),
                     }
                 }
-                fn visit_str<__E>(self, __value: &str) -> _serde::export::Result<Self::Value, __E>
+                fn visit_str<__E>(
+                    self,
+                    __value: &str,
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
-                        _ => _serde::export::Err(_serde::de::Error::unknown_variant(
+                        _ => _serde::__private::Err(_serde::de::Error::unknown_variant(
                             __value, VARIANTS,
                         )),
                     }
@@ -61,14 +67,14 @@ const _IMPL_DESERIALIZE_FOR_Void: () = {
                 fn visit_bytes<__E>(
                     self,
                     __value: &[u8],
-                ) -> _serde::export::Result<Self::Value, __E>
+                ) -> _serde::__private::Result<Self::Value, __E>
                 where
                     __E: _serde::de::Error,
                 {
                     match __value {
                         _ => {
-                            let __value = &_serde::export::from_utf8_lossy(__value);
-                            _serde::export::Err(_serde::de::Error::unknown_variant(
+                            let __value = &_serde::__private::from_utf8_lossy(__value);
+                            _serde::__private::Err(_serde::de::Error::unknown_variant(
                                 __value, VARIANTS,
                             ))
                         }
@@ -77,7 +83,9 @@ const _IMPL_DESERIALIZE_FOR_Void: () = {
             }
             impl<'de> _serde::Deserialize<'de> for __Field {
                 #[inline]
-                fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<Self, __D::Error>
+                fn deserialize<__D>(
+                    __deserializer: __D,
+                ) -> _serde::__private::Result<Self, __D::Error>
                 where
                     __D: _serde::Deserializer<'de>,
                 {
@@ -85,25 +93,25 @@ const _IMPL_DESERIALIZE_FOR_Void: () = {
                 }
             }
             struct __Visitor<'de> {
-                marker: _serde::export::PhantomData<Void>,
-                lifetime: _serde::export::PhantomData<&'de ()>,
+                marker: _serde::__private::PhantomData<Void>,
+                lifetime: _serde::__private::PhantomData<&'de ()>,
             }
             impl<'de> _serde::de::Visitor<'de> for __Visitor<'de> {
                 type Value = Void;
                 fn expecting(
                     &self,
-                    __formatter: &mut _serde::export::Formatter,
-                ) -> _serde::export::fmt::Result {
-                    _serde::export::Formatter::write_str(__formatter, "enum Void")
+                    __formatter: &mut _serde::__private::Formatter,
+                ) -> _serde::__private::fmt::Result {
+                    _serde::__private::Formatter::write_str(__formatter, "enum Void")
                 }
                 fn visit_enum<__A>(
                     self,
                     __data: __A,
-                ) -> _serde::export::Result<Self::Value, __A::Error>
+                ) -> _serde::__private::Result<Self::Value, __A::Error>
                 where
                     __A: _serde::de::EnumAccess<'de>,
                 {
-                    _serde::export::Result::map(
+                    _serde::__private::Result::map(
                         _serde::de::EnumAccess::variant::<__Field>(__data),
                         |(__impossible, _)| match __impossible {},
                     )
@@ -115,8 +123,8 @@ const _IMPL_DESERIALIZE_FOR_Void: () = {
                 "Void",
                 VARIANTS,
                 __Visitor {
-                    marker: _serde::export::PhantomData::<Void>,
-                    lifetime: _serde::export::PhantomData,
+                    marker: _serde::__private::PhantomData::<Void>,
+                    lifetime: _serde::__private::PhantomData,
                 },
             )
         }

test_suite/tests/expandtest.rs

@@ -1,6 +1,7 @@
 #[cfg_attr(target_os = "emscripten", ignore)]
 #[cfg_attr(not(expandtest), ignore)]
 #[rustversion::attr(not(nightly), ignore)]
+#[allow(unused_attributes)]
 #[test]
 fn expandtest() {
     macrotest::expand("tests/expand/*.rs");

test_suite/tests/test_annotations.rs

@@ -1,4 +1,8 @@
-#![allow(clippy::cast_lossless, clippy::trivially_copy_pass_by_ref)]
+#![allow(
+    clippy::cast_lossless,
+    clippy::from_over_into,
+    clippy::trivially_copy_pass_by_ref
+)]
 
 use serde::de::{self, MapAccess, Unexpected, Visitor};
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
@@ -1967,6 +1971,29 @@ fn test_flatten_map_twice() {
     );
 }
 
+#[test]
+fn test_flatten_unit() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    struct Response<T> {
+        #[serde(flatten)]
+        data: T,
+        status: usize,
+    }
+
+    assert_tokens(
+        &Response {
+            data: (),
+            status: 0,
+        },
+        &[
+            Token::Map { len: None },
+            Token::Str("status"),
+            Token::U64(0),
+            Token::MapEnd,
+        ],
+    );
+}
+
 #[test]
 fn test_flatten_unsupported_type() {
     #[derive(Debug, PartialEq, Serialize, Deserialize)]
@@ -2610,3 +2637,171 @@ fn test_flatten_any_after_flatten_struct() {
         ],
     );
 }
+
+#[test]
+fn test_expecting_message() {
+    #[derive(Deserialize, PartialEq, Debug)]
+    #[serde(expecting = "something strange...")]
+    struct Unit;
+
+    #[derive(Deserialize)]
+    #[serde(expecting = "something strange...")]
+    struct Newtype(bool);
+
+    #[derive(Deserialize)]
+    #[serde(expecting = "something strange...")]
+    struct Tuple(u32, bool);
+
+    #[derive(Deserialize)]
+    #[serde(expecting = "something strange...")]
+    struct Struct {
+        question: String,
+        answer: u32,
+    }
+
+    assert_de_tokens_error::<Unit>(
+        &[Token::Str("Unit")],
+        r#"invalid type: string "Unit", expected something strange..."#,
+    );
+
+    assert_de_tokens_error::<Newtype>(
+        &[Token::Str("Newtype")],
+        r#"invalid type: string "Newtype", expected something strange..."#,
+    );
+
+    assert_de_tokens_error::<Tuple>(
+        &[Token::Str("Tuple")],
+        r#"invalid type: string "Tuple", expected something strange..."#,
+    );
+
+    assert_de_tokens_error::<Struct>(
+        &[Token::Str("Struct")],
+        r#"invalid type: string "Struct", expected something strange..."#,
+    );
+}
+
+#[test]
+fn test_expecting_message_externally_tagged_enum() {
+    #[derive(Deserialize)]
+    #[serde(expecting = "something strange...")]
+    enum Enum {
+        ExternallyTagged,
+    }
+
+    assert_de_tokens_error::<Enum>(
+        &[Token::Str("ExternallyTagged")],
+        r#"invalid type: string "ExternallyTagged", expected something strange..."#,
+    );
+
+    // Check that #[serde(expecting = "...")] doesn't affect variant identifier error message
+    assert_de_tokens_error::<Enum>(
+        &[Token::Enum { name: "Enum" }, Token::Unit],
+        r#"invalid type: unit value, expected variant identifier"#,
+    );
+}
+
+#[test]
+fn test_expecting_message_internally_tagged_enum() {
+    #[derive(Deserialize)]
+    #[serde(tag = "tag")]
+    #[serde(expecting = "something strange...")]
+    enum Enum {
+        InternallyTagged,
+    }
+
+    assert_de_tokens_error::<Enum>(
+        &[Token::Str("InternallyTagged")],
+        r#"invalid type: string "InternallyTagged", expected something strange..."#,
+    );
+
+    // Check that #[serde(expecting = "...")] doesn't affect variant identifier error message
+    assert_de_tokens_error::<Enum>(
+        &[Token::Map { len: None }, Token::Str("tag"), Token::Unit],
+        r#"invalid type: unit value, expected variant identifier"#,
+    );
+}
+
+#[test]
+fn test_expecting_message_adjacently_tagged_enum() {
+    #[derive(Deserialize)]
+    #[serde(tag = "tag", content = "content")]
+    #[serde(expecting = "something strange...")]
+    enum Enum {
+        AdjacentlyTagged,
+    }
+
+    assert_de_tokens_error::<Enum>(
+        &[Token::Str("AdjacentlyTagged")],
+        r#"invalid type: string "AdjacentlyTagged", expected something strange..."#,
+    );
+
+    assert_de_tokens_error::<Enum>(
+        &[Token::Map { len: None }, Token::Unit],
+        r#"invalid type: unit value, expected "tag", "content", or other ignored fields"#,
+    );
+
+    // Check that #[serde(expecting = "...")] doesn't affect variant identifier error message
+    assert_de_tokens_error::<Enum>(
+        &[Token::Map { len: None }, Token::Str("tag"), Token::Unit],
+        r#"invalid type: unit value, expected variant identifier"#,
+    );
+}
+
+#[test]
+fn test_expecting_message_untagged_tagged_enum() {
+    #[derive(Deserialize)]
+    #[serde(untagged)]
+    #[serde(expecting = "something strange...")]
+    enum Enum {
+        Untagged,
+    }
+
+    assert_de_tokens_error::<Enum>(&[Token::Str("Untagged")], r#"something strange..."#);
+}
+
+#[test]
+fn test_expecting_message_identifier_enum() {
+    #[derive(Deserialize)]
+    #[serde(field_identifier)]
+    #[serde(expecting = "something strange...")]
+    enum FieldEnum {
+        Field,
+    }
+
+    #[derive(Deserialize)]
+    #[serde(variant_identifier)]
+    #[serde(expecting = "something strange...")]
+    enum VariantEnum {
+        Variant,
+    }
+
+    assert_de_tokens_error::<FieldEnum>(
+        &[Token::Unit],
+        r#"invalid type: unit value, expected something strange..."#,
+    );
+
+    assert_de_tokens_error::<FieldEnum>(
+        &[
+            Token::Enum { name: "FieldEnum" },
+            Token::Str("Unknown"),
+            Token::None,
+        ],
+        r#"invalid type: map, expected something strange..."#,
+    );
+
+    assert_de_tokens_error::<VariantEnum>(
+        &[Token::Unit],
+        r#"invalid type: unit value, expected something strange..."#,
+    );
+
+    assert_de_tokens_error::<VariantEnum>(
+        &[
+            Token::Enum {
+                name: "VariantEnum",
+            },
+            Token::Str("Unknown"),
+            Token::None,
+        ],
+        r#"invalid type: map, expected something strange..."#,
+    );
+}

test_suite/tests/test_borrow.rs

@@ -90,6 +90,30 @@ fn test_struct() {
     );
 }
 
+#[test]
+fn test_field_identifier() {
+    #[derive(Deserialize, Debug, PartialEq)]
+    #[serde(field_identifier)]
+    enum FieldStr<'a> {
+        #[serde(borrow)]
+        Str(&'a str),
+    }
+
+    assert_de_tokens(&FieldStr::Str("value"), &[Token::BorrowedStr("value")]);
+
+    #[derive(Deserialize, Debug, PartialEq)]
+    #[serde(field_identifier)]
+    enum FieldBytes<'a> {
+        #[serde(borrow)]
+        Bytes(&'a [u8]),
+    }
+
+    assert_de_tokens(
+        &FieldBytes::Bytes(b"value"),
+        &[Token::BorrowedBytes(b"value")],
+    );
+}
+
 #[test]
 fn test_cow() {
     #[derive(Deserialize)]

test_suite/tests/test_de.rs

@@ -15,7 +15,7 @@ use std::sync::atomic::{
     AtomicUsize, Ordering,
 };
 use std::sync::{Arc, Weak as ArcWeak};
-use std::time::{Duration, UNIX_EPOCH};
+use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
 #[cfg(target_arch = "x86_64")]
 use std::sync::atomic::{AtomicI64, AtomicU64};
@@ -192,8 +192,12 @@ macro_rules! declare_tests {
 }
 
 macro_rules! declare_error_tests {
-    ($($name:ident<$target:ty> { $tokens:expr, $expected:expr, })+) => {
+    ($(
+        $(#[$cfg:meta])*
+        $name:ident<$target:ty> { $tokens:expr, $expected:expr, }
+    )+) => {
         $(
+            $(#[$cfg])*
             #[test]
             fn $name() {
                 assert_de_tokens_error::<$target>($tokens, $expected);
@@ -622,6 +626,24 @@ declare_tests! {
                 Token::I32(2),
             Token::MapEnd,
         ],
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Map { len: Some(3) },
+                Token::U8(0),
+                Token::I32(1),
+
+                Token::U8(1),
+                Token::I32(2),
+            Token::MapEnd,
+        ],
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Map { len: Some(3) },
+                Token::U16(0),
+                Token::I32(1),
+
+                Token::U16(1),
+                Token::I32(2),
+            Token::MapEnd,
+        ],
         Struct { a: 1, b: 2, c: 0 } => &[
             Token::Map { len: Some(3) },
                 Token::U32(0),
@@ -631,6 +653,34 @@ declare_tests! {
                 Token::I32(2),
             Token::MapEnd,
         ],
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Map { len: Some(3) },
+                Token::U64(0),
+                Token::I32(1),
+
+                Token::U64(1),
+                Token::I32(2),
+            Token::MapEnd,
+        ],
+        // Mixed key types
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Map { len: Some(3) },
+                Token::U8(0),
+                Token::I32(1),
+
+                Token::U64(1),
+                Token::I32(2),
+            Token::MapEnd,
+        ],
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Map { len: Some(3) },
+                Token::U8(0),
+                Token::I32(1),
+
+                Token::Str("b"),
+                Token::I32(2),
+            Token::MapEnd,
+        ],
         Struct { a: 1, b: 2, c: 0 } => &[
             Token::Struct { name: "Struct", len: 2 },
                 Token::Str("a"),
@@ -647,6 +697,46 @@ declare_tests! {
             Token::SeqEnd,
         ],
     }
+    test_struct_borrowed_keys {
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Map { len: Some(3) },
+                Token::BorrowedStr("a"),
+                Token::I32(1),
+
+                Token::BorrowedStr("b"),
+                Token::I32(2),
+            Token::MapEnd,
+        ],
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Struct { name: "Struct", len: 2 },
+                Token::BorrowedStr("a"),
+                Token::I32(1),
+
+                Token::BorrowedStr("b"),
+                Token::I32(2),
+            Token::StructEnd,
+        ],
+    }
+    test_struct_owned_keys {
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Map { len: Some(3) },
+                Token::String("a"),
+                Token::I32(1),
+
+                Token::String("b"),
+                Token::I32(2),
+            Token::MapEnd,
+        ],
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Struct { name: "Struct", len: 2 },
+                Token::String("a"),
+                Token::I32(1),
+
+                Token::String("b"),
+                Token::I32(2),
+            Token::StructEnd,
+        ],
+    }
     test_struct_with_skip {
         Struct { a: 1, b: 2, c: 0 } => &[
             Token::Map { len: Some(3) },
@@ -663,6 +753,21 @@ declare_tests! {
                 Token::I32(4),
             Token::MapEnd,
         ],
+        Struct { a: 1, b: 2, c: 0 } => &[
+            Token::Map { len: Some(3) },
+                Token::U8(0),
+                Token::I32(1),
+
+                Token::U16(1),
+                Token::I32(2),
+
+                Token::U32(2),
+                Token::I32(3),
+
+                Token::U64(3),
+                Token::I32(4),
+            Token::MapEnd,
+        ],
         Struct { a: 1, b: 2, c: 0 } => &[
             Token::Struct { name: "Struct", len: 2 },
                 Token::Str("a"),
@@ -780,6 +885,26 @@ declare_tests! {
             Token::Str("Unit"),
             Token::Unit,
         ],
+        EnumOther::Unit => &[
+            Token::Enum { name: "EnumOther" },
+            Token::U8(0),
+            Token::Unit,
+        ],
+        EnumOther::Unit => &[
+            Token::Enum { name: "EnumOther" },
+            Token::U16(0),
+            Token::Unit,
+        ],
+        EnumOther::Unit => &[
+            Token::Enum { name: "EnumOther" },
+            Token::U32(0),
+            Token::Unit,
+        ],
+        EnumOther::Unit => &[
+            Token::Enum { name: "EnumOther" },
+            Token::U64(0),
+            Token::Unit,
+        ],
     }
     test_enum_other {
         EnumOther::Other => &[
@@ -787,6 +912,26 @@ declare_tests! {
             Token::Str("Foo"),
             Token::Unit,
         ],
+        EnumOther::Other => &[
+            Token::Enum { name: "EnumOther" },
+            Token::U8(42),
+            Token::Unit,
+        ],
+        EnumOther::Other => &[
+            Token::Enum { name: "EnumOther" },
+            Token::U16(42),
+            Token::Unit,
+        ],
+        EnumOther::Other => &[
+            Token::Enum { name: "EnumOther" },
+            Token::U32(42),
+            Token::Unit,
+        ],
+        EnumOther::Other => &[
+            Token::Enum { name: "EnumOther" },
+            Token::U64(42),
+            Token::Unit,
+        ],
     }
     test_box {
         Box::new(0i32) => &[Token::I32(0)],
@@ -1452,4 +1597,56 @@ declare_error_tests! {
         ],
         "invalid value: integer `65536`, expected u16",
     }
+    test_duration_overflow_seq<Duration> {
+        &[
+            Token::Seq { len: Some(2) },
+                Token::U64(u64::max_value()),
+                Token::U32(1_000_000_000),
+            Token::SeqEnd,
+        ],
+        "overflow deserializing Duration",
+    }
+    test_duration_overflow_struct<Duration> {
+        &[
+            Token::Struct { name: "Duration", len: 2 },
+                Token::Str("secs"),
+                Token::U64(u64::max_value()),
+
+                Token::Str("nanos"),
+                Token::U32(1_000_000_000),
+            Token::StructEnd,
+        ],
+        "overflow deserializing Duration",
+    }
+    test_systemtime_overflow_seq<SystemTime> {
+        &[
+            Token::Seq { len: Some(2) },
+                Token::U64(u64::max_value()),
+                Token::U32(1_000_000_000),
+            Token::SeqEnd,
+        ],
+        "overflow deserializing SystemTime epoch offset",
+    }
+    test_systemtime_overflow_struct<SystemTime> {
+        &[
+            Token::Struct { name: "SystemTime", len: 2 },
+                Token::Str("secs_since_epoch"),
+                Token::U64(u64::max_value()),
+
+                Token::Str("nanos_since_epoch"),
+                Token::U32(1_000_000_000),
+            Token::StructEnd,
+        ],
+        "overflow deserializing SystemTime epoch offset",
+    }
+    #[cfg(systemtime_checked_add)]
+    test_systemtime_overflow<SystemTime> {
+        &[
+            Token::Seq { len: Some(2) },
+                Token::U64(u64::max_value()),
+                Token::U32(0),
+            Token::SeqEnd,
+        ],
+        "overflow deserializing SystemTime",
+    }
 }

test_suite/tests/test_gen.rs

@@ -4,7 +4,12 @@
 
 #![deny(warnings)]
 #![cfg_attr(feature = "unstable", feature(non_ascii_idents))]
-#![allow(clippy::trivially_copy_pass_by_ref)]
+#![allow(
+    unknown_lints,
+    mixed_script_confusables,
+    clippy::ptr_arg,
+    clippy::trivially_copy_pass_by_ref
+)]
 
 use serde::de::DeserializeOwned;
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
@@ -701,6 +706,42 @@ fn test_gen() {
         #[serde(other)]
         Unknown,
     }
+
+    #[derive(Serialize)]
+    #[repr(packed)]
+    struct Packed {
+        x: u8,
+        y: u16,
+    }
+
+    macro_rules! deriving {
+        ($field:ty) => {
+            #[derive(Deserialize)]
+            struct MacroRules<'a> {
+                field: $field,
+            }
+        };
+    }
+
+    deriving!(&'a str);
+
+    macro_rules! mac {
+        ($($tt:tt)*) => {
+            $($tt)*
+        };
+    }
+
+    #[derive(Deserialize)]
+    struct BorrowLifetimeInsideMacro<'a> {
+        #[serde(borrow = "'a")]
+        f: mac!(Cow<'a, str>),
+    }
+
+    #[derive(Serialize)]
+    struct Struct {
+        #[serde(serialize_with = "vec_first_element")]
+        vec: Vec<Self>,
+    }
 }
 
 //////////////////////////////////////////////////////////////////////////
@@ -774,3 +815,11 @@ where
 pub fn is_zero(n: &u8) -> bool {
     *n == 0
 }
+
+fn vec_first_element<T, S>(vec: &Vec<T>, serializer: S) -> StdResult<S::Ok, S::Error>
+where
+    T: Serialize,
+    S: Serializer,
+{
+    vec.first().serialize(serializer)
+}

test_suite/tests/test_identifier.rs

@@ -1,3 +1,4 @@
+//! Tests for `#[serde(field_identifier)]` and `#[serde(variant_identifier)]`
 use serde::Deserialize;
 use serde_test::{assert_de_tokens, Token};
 
@@ -27,6 +28,10 @@ fn test_field_identifier() {
         Bbb,
     }
 
+    assert_de_tokens(&F::Aaa, &[Token::U8(0)]);
+    assert_de_tokens(&F::Aaa, &[Token::U16(0)]);
+    assert_de_tokens(&F::Aaa, &[Token::U32(0)]);
+    assert_de_tokens(&F::Aaa, &[Token::U64(0)]);
     assert_de_tokens(&F::Aaa, &[Token::Str("aaa")]);
     assert_de_tokens(&F::Aaa, &[Token::Bytes(b"aaa")]);
 }
@@ -42,6 +47,10 @@ fn test_unit_fallthrough() {
         Other,
     }
 
+    assert_de_tokens(&F::Other, &[Token::U8(42)]);
+    assert_de_tokens(&F::Other, &[Token::U16(42)]);
+    assert_de_tokens(&F::Other, &[Token::U32(42)]);
+    assert_de_tokens(&F::Other, &[Token::U64(42)]);
     assert_de_tokens(&F::Other, &[Token::Str("x")]);
 }
 
@@ -68,5 +77,9 @@ fn test_newtype_fallthrough_generic() {
         Other(T),
     }
 
+    assert_de_tokens(&F::Other(42u8), &[Token::U8(42)]);
+    assert_de_tokens(&F::Other(42u16), &[Token::U16(42)]);
+    assert_de_tokens(&F::Other(42u32), &[Token::U32(42)]);
+    assert_de_tokens(&F::Other(42u64), &[Token::U64(42)]);
     assert_de_tokens(&F::Other("x".to_owned()), &[Token::Str("x")]);
 }

test_suite/tests/test_macros.rs

@@ -994,6 +994,28 @@ fn test_internally_tagged_struct_variant_containing_unit_variant() {
             Token::StructEnd,
         ],
     );
+
+    assert_de_tokens(
+        &Message::Log { level: Level::Info },
+        &[
+            Token::Map { len: Some(2) },
+            Token::Str("action"),
+            Token::Str("Log"),
+            Token::Str("level"),
+            Token::BorrowedStr("Info"),
+            Token::MapEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Message::Log { level: Level::Info },
+        &[
+            Token::Seq { len: Some(2) },
+            Token::Str("Log"),
+            Token::BorrowedStr("Info"),
+            Token::SeqEnd,
+        ],
+    );
 }
 
 #[test]
@@ -1145,6 +1167,20 @@ fn test_adjacently_tagged_enum() {
         ],
     );
 
+    // optional newtype with no content field
+    assert_de_tokens(
+        &AdjacentlyTagged::Newtype::<Option<u8>>(None),
+        &[
+            Token::Struct {
+                name: "AdjacentlyTagged",
+                len: 1,
+            },
+            Token::Str("t"),
+            Token::Str("Newtype"),
+            Token::StructEnd,
+        ],
+    );
+
     // tuple with tag first
     assert_tokens(
         &AdjacentlyTagged::Tuple::<u8>(1, 1),
@@ -1863,4 +1899,54 @@ fn test_internally_tagged_newtype_variant_containing_unit_struct() {
             Token::MapEnd,
         ],
     );
+
+    assert_de_tokens(
+        &Message::Info(Info),
+        &[
+            Token::Struct {
+                name: "Message",
+                len: 1,
+            },
+            Token::Str("topic"),
+            Token::Str("Info"),
+            Token::StructEnd,
+        ],
+    );
+
+    assert_de_tokens(
+        &Message::Info(Info),
+        &[
+            Token::Seq { len: Some(1) },
+            Token::Str("Info"),
+            Token::SeqEnd,
+        ],
+    );
+}
+
+#[deny(safe_packed_borrows)]
+#[test]
+fn test_packed_struct_can_derive_serialize() {
+    #[derive(Copy, Clone, Serialize)]
+    #[repr(packed, C)]
+    struct PackedC {
+        t: f32,
+    }
+
+    #[derive(Copy, Clone, Serialize)]
+    #[repr(C, packed)]
+    struct CPacked {
+        t: f32,
+    }
+
+    #[derive(Copy, Clone, Serialize)]
+    #[repr(C, packed(2))]
+    struct CPacked2 {
+        t: f32,
+    }
+
+    #[derive(Copy, Clone, Serialize)]
+    #[repr(packed(2), C)]
+    struct Packed2C {
+        t: f32,
+    }
 }

test_suite/tests/test_self.rs

@@ -0,0 +1,86 @@
+use serde::{Deserialize, Serialize};
+
+#[test]
+fn test_self() {
+    pub trait Trait {
+        type Assoc;
+    }
+
+    #[derive(Deserialize, Serialize)]
+    pub struct Generics<T: Trait<Assoc = Self>>
+    where
+        Self: Trait<Assoc = Self>,
+        <Self as Trait>::Assoc: Sized,
+    {
+        _f: T,
+    }
+
+    impl<T: Trait<Assoc = Self>> Trait for Generics<T> {
+        type Assoc = Self;
+    }
+
+    #[derive(Deserialize, Serialize)]
+    pub struct Struct {
+        _f1: Box<Self>,
+        _f2: Box<<Self as Trait>::Assoc>,
+        _f4: [(); Self::ASSOC],
+        _f5: [(); Self::assoc()],
+    }
+
+    impl Struct {
+        const ASSOC: usize = 1;
+        const fn assoc() -> usize {
+            0
+        }
+    }
+
+    impl Trait for Struct {
+        type Assoc = Self;
+    }
+
+    #[derive(Deserialize, Serialize)]
+    struct Tuple(
+        Box<Self>,
+        Box<<Self as Trait>::Assoc>,
+        [(); Self::ASSOC],
+        [(); Self::assoc()],
+    );
+
+    impl Tuple {
+        const ASSOC: usize = 1;
+        const fn assoc() -> usize {
+            0
+        }
+    }
+
+    impl Trait for Tuple {
+        type Assoc = Self;
+    }
+
+    #[derive(Deserialize, Serialize)]
+    enum Enum {
+        Struct {
+            _f1: Box<Self>,
+            _f2: Box<<Self as Trait>::Assoc>,
+            _f4: [(); Self::ASSOC],
+            _f5: [(); Self::assoc()],
+        },
+        Tuple(
+            Box<Self>,
+            Box<<Self as Trait>::Assoc>,
+            [(); Self::ASSOC],
+            [(); Self::assoc()],
+        ),
+    }
+
+    impl Enum {
+        const ASSOC: usize = 1;
+        const fn assoc() -> usize {
+            0
+        }
+    }
+
+    impl Trait for Enum {
+        type Assoc = Self;
+    }
+}

test_suite/tests/ui/remote/wrong_de.stderr

@@ -5,6 +5,6 @@ error[E0308]: mismatched types
   |          ^^^^^^^^^^^
   |          |
   |          expected `u16`, found `u8`
-  |          help: you can convert an `u8` to `u16`: `Deserialize.into()`
+  |          help: you can convert a `u8` to a `u16`: `Deserialize.into()`
   |
   = note: this error originates in a derive macro (in Nightly builds, run with -Z macro-backtrace for more info)

test_suite/tests/ui/rename/container_unknown_rename_rule.stderr

@@ -1,4 +1,4 @@
-error: unknown rename rule for #[serde(rename_all = "abc")]
+error: unknown rename rule `rename_all = "abc"`, expected one of "lowercase", "UPPERCASE", "PascalCase", "camelCase", "snake_case", "SCREAMING_SNAKE_CASE", "kebab-case", "SCREAMING-KEBAB-CASE"
  --> $DIR/container_unknown_rename_rule.rs:4:22
   |
 4 | #[serde(rename_all = "abc")]

test_suite/tests/ui/rename/variant_unknown_rename_rule.stderr

@@ -1,4 +1,4 @@
-error: unknown rename rule for #[serde(rename_all = "abc")]
+error: unknown rename rule `rename_all = "abc"`, expected one of "lowercase", "UPPERCASE", "PascalCase", "camelCase", "snake_case", "SCREAMING_SNAKE_CASE", "kebab-case", "SCREAMING-KEBAB-CASE"
  --> $DIR/variant_unknown_rename_rule.rs:5:26
   |
 5 |     #[serde(rename_all = "abc")]