Release 1.0.134

Write better Visitor for NonZero integers

.github/workflows/ci.yml

@@ -5,6 +5,9 @@ on:
   pull_request:
   schedule: [cron: "40 1 * * *"]
 
+env:
+  RUSTFLAGS: -Dwarnings
+
 jobs:
   test:
     name: Test suite

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.131" # remember to update html_root_url and serde_derive dependency
+version = "1.0.134" # remember to update html_root_url and serde_derive dependency
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 rust-version = "1.15"
 license = "MIT OR Apache-2.0"
@@ -15,7 +15,7 @@ include = ["build.rs", "src/**/*.rs", "crates-io.md", "README.md", "LICENSE-APAC
 build = "build.rs"
 
 [dependencies]
-serde_derive = { version = "=1.0.131", optional = true, path = "../serde_derive" }
+serde_derive = { version = "=1.0.134", optional = true, path = "../serde_derive" }
 
 [dev-dependencies]
 serde_derive = { version = "1.0", path = "../serde_derive" }

serde/build.rs

@@ -17,37 +17,38 @@ fn main() {
     // std::collections::Bound was stabilized in Rust 1.17
     // but it was moved to core::ops later in Rust 1.26:
     // https://doc.rust-lang.org/core/ops/enum.Bound.html
-    if minor >= 26 {
-        println!("cargo:rustc-cfg=ops_bound");
-    } else if minor >= 17 && cfg!(feature = "std") {
-        println!("cargo:rustc-cfg=collections_bound");
+    if minor < 26 {
+        println!("cargo:rustc-cfg=no_ops_bound");
+        if minor < 17 {
+            println!("cargo:rustc-cfg=no_collections_bound");
+        }
     }
 
     // core::cmp::Reverse stabilized in Rust 1.19:
     // https://doc.rust-lang.org/stable/core/cmp/struct.Reverse.html
-    if minor >= 19 {
-        println!("cargo:rustc-cfg=core_reverse");
+    if minor < 19 {
+        println!("cargo:rustc-cfg=no_core_reverse");
     }
 
     // CString::into_boxed_c_str and PathBuf::into_boxed_path stabilized in Rust 1.20:
     // https://doc.rust-lang.org/std/ffi/struct.CString.html#method.into_boxed_c_str
     // https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.into_boxed_path
-    if minor >= 20 {
-        println!("cargo:rustc-cfg=de_boxed_c_str");
-        println!("cargo:rustc-cfg=de_boxed_path");
+    if minor < 20 {
+        println!("cargo:rustc-cfg=no_de_boxed_c_str");
+        println!("cargo:rustc-cfg=no_de_boxed_path");
     }
 
     // From<Box<T>> for Rc<T> / Arc<T> stabilized in Rust 1.21:
     // https://doc.rust-lang.org/std/rc/struct.Rc.html#impl-From<Box<T>>
     // https://doc.rust-lang.org/std/sync/struct.Arc.html#impl-From<Box<T>>
-    if minor >= 21 {
-        println!("cargo:rustc-cfg=de_rc_dst");
+    if minor < 21 {
+        println!("cargo:rustc-cfg=no_de_rc_dst");
     }
 
     // Duration available in core since Rust 1.25:
     // https://blog.rust-lang.org/2018/03/29/Rust-1.25.html#library-stabilizations
-    if minor >= 25 {
-        println!("cargo:rustc-cfg=core_duration");
+    if minor < 25 {
+        println!("cargo:rustc-cfg=no_core_duration");
     }
 
     // 128-bit integers stabilized in Rust 1.26:
@@ -56,55 +57,56 @@ fn main() {
     // Disabled on Emscripten targets before Rust 1.40 since
     // Emscripten did not support 128-bit integers until Rust 1.40
     // (https://github.com/rust-lang/rust/pull/65251)
-    if minor >= 26 && (!emscripten || minor >= 40) {
-        println!("cargo:rustc-cfg=integer128");
+    if minor < 26 || emscripten && minor < 40 {
+        println!("cargo:rustc-cfg=no_integer128");
     }
 
     // Inclusive ranges methods stabilized in Rust 1.27:
     // https://github.com/rust-lang/rust/pull/50758
     // Also Iterator::try_for_each:
     // https://blog.rust-lang.org/2018/06/21/Rust-1.27.html#library-stabilizations
-    if minor >= 27 {
-        println!("cargo:rustc-cfg=range_inclusive");
-        println!("cargo:rustc-cfg=iterator_try_fold");
+    if minor < 27 {
+        println!("cargo:rustc-cfg=no_range_inclusive");
+        println!("cargo:rustc-cfg=no_iterator_try_fold");
     }
 
     // Non-zero integers stabilized in Rust 1.28:
     // https://blog.rust-lang.org/2018/08/02/Rust-1.28.html#library-stabilizations
-    if minor >= 28 {
-        println!("cargo:rustc-cfg=num_nonzero");
+    if minor < 28 {
+        println!("cargo:rustc-cfg=no_num_nonzero");
     }
 
     // Current minimum supported version of serde_derive crate is Rust 1.31.
-    if minor >= 31 {
-        println!("cargo:rustc-cfg=serde_derive");
+    if minor < 31 {
+        println!("cargo:rustc-cfg=no_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");
+    if minor < 34 {
+        println!("cargo:rustc-cfg=no_core_try_from");
+        println!("cargo:rustc-cfg=no_num_nonzero_signed");
+        println!("cargo:rustc-cfg=no_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.
-        // Instead this is based on rustc's src/librustc_target/spec/*.rs.
-        let has_atomic64 = target.starts_with("x86_64")
-            || target.starts_with("i686")
-            || target.starts_with("aarch64")
-            || target.starts_with("powerpc64")
-            || target.starts_with("sparc64")
-            || target.starts_with("mips64el");
-        let has_atomic32 = has_atomic64 || emscripten;
-        if has_atomic64 {
-            println!("cargo:rustc-cfg=std_atomic64");
-        }
-        if has_atomic32 {
-            println!("cargo:rustc-cfg=std_atomic");
-        }
+    // Whitelist of archs that support std::sync::atomic module. Ideally we
+    // would use #[cfg(target_has_atomic = "...")] but it is not stable yet.
+    // Instead this is based on rustc's compiler/rustc_target/src/spec/*.rs.
+    let has_atomic64 = target.starts_with("x86_64")
+        || target.starts_with("i686")
+        || target.starts_with("aarch64")
+        || target.starts_with("powerpc64")
+        || target.starts_with("sparc64")
+        || target.starts_with("mips64el")
+        || target.starts_with("riscv64");
+    let has_atomic32 = has_atomic64 || emscripten;
+    if minor < 34 || !has_atomic64 {
+        println!("cargo:rustc-cfg=no_std_atomic64");
+    }
+    if minor < 34 || !has_atomic32 {
+        println!("cargo:rustc-cfg=no_std_atomic");
     }
 }
 

serde/src/de/impls.rs

@@ -4,7 +4,7 @@ use de::{
     Deserialize, Deserializer, EnumAccess, Error, SeqAccess, Unexpected, VariantAccess, Visitor,
 };
 
-#[cfg(any(core_duration, feature = "std", feature = "alloc"))]
+#[cfg(any(feature = "std", feature = "alloc", not(no_core_duration)))]
 use de::MapAccess;
 
 use seed::InPlaceSeed;
@@ -81,8 +81,34 @@ impl<'de> Deserialize<'de> for bool {
 ////////////////////////////////////////////////////////////////////////////////
 
 macro_rules! impl_deserialize_num {
-    ($ty:ident, $deserialize:ident $($methods:tt)*) => {
-        impl<'de> Deserialize<'de> for $ty {
+    ($primitive:ident, $nonzero:ident $(cfg($($cfg:tt)*))*, $deserialize:ident $($method:ident!($($val:ident : $visit:ident)*);)*) => {
+        impl_deserialize_num!($primitive, $deserialize $($method!($($val : $visit)*);)*);
+
+        #[cfg(all(not(no_num_nonzero), $($($cfg)*)*))]
+        impl<'de> Deserialize<'de> for num::$nonzero {
+            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+            where
+                D: Deserializer<'de>,
+            {
+                struct NonZeroVisitor;
+
+                impl<'de> Visitor<'de> for NonZeroVisitor {
+                    type Value = num::$nonzero;
+
+                    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                        formatter.write_str(concat!("a nonzero ", stringify!($primitive)))
+                    }
+
+                    $($($method!(nonzero $primitive $val : $visit);)*)*
+                }
+
+                deserializer.$deserialize(NonZeroVisitor)
+            }
+        }
+    };
+
+    ($primitive:ident, $deserialize:ident $($method:ident!($($val:ident : $visit:ident)*);)*) => {
+        impl<'de> Deserialize<'de> for $primitive {
             #[inline]
             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
             where
@@ -91,13 +117,13 @@ macro_rules! impl_deserialize_num {
                 struct PrimitiveVisitor;
 
                 impl<'de> Visitor<'de> for PrimitiveVisitor {
-                    type Value = $ty;
+                    type Value = $primitive;
 
                     fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-                        formatter.write_str(stringify!($ty))
+                        formatter.write_str(stringify!($primitive))
                     }
 
-                    $($methods)*
+                    $($($method!($val : $visit);)*)*
                 }
 
                 deserializer.$deserialize(PrimitiveVisitor)
@@ -116,85 +142,149 @@ macro_rules! num_self {
             Ok(v)
         }
     };
+
+    (nonzero $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if let Some(nonzero) = Self::Value::new(v) {
+                Ok(nonzero)
+            } else {
+                Err(Error::invalid_value(Unexpected::Unsigned(0), &self))
+            }
+        }
+    };
 }
 
 macro_rules! num_as_self {
-    ($($ty:ident : $visit:ident)*) => {
-        $(
-            #[inline]
-            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
-            where
-                E: Error,
-            {
-                Ok(v as Self::Value)
+    ($ty:ident : $visit:ident) => {
+        #[inline]
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            Ok(v as Self::Value)
+        }
+    };
+
+    (nonzero $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if let Some(nonzero) = Self::Value::new(v as $primitive) {
+                Ok(nonzero)
+            } else {
+                Err(Error::invalid_value(Unexpected::Unsigned(0), &self))
             }
-        )*
+        }
     };
 }
 
 macro_rules! int_to_int {
-    ($($ty:ident : $visit:ident)*) => {
-        $(
-            #[inline]
-            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
-            where
-                E: Error,
+    ($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
             {
-                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))
+                Ok(v as Self::Value)
+            } else {
+                Err(Error::invalid_value(Unexpected::Signed(v as i64), &self))
+            }
+        }
+    };
+
+    (nonzero $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if $primitive::min_value() as i64 <= v as i64
+                && v as i64 <= $primitive::max_value() as i64
+            {
+                if let Some(nonzero) = Self::Value::new(v as $primitive) {
+                    return Ok(nonzero);
                 }
             }
-        )*
+            Err(Error::invalid_value(Unexpected::Signed(v as i64), &self))
+        }
     };
 }
 
 macro_rules! int_to_uint {
-    ($($ty:ident : $visit:ident)*) => {
-        $(
-            #[inline]
-            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
-            where
-                E: Error,
-            {
-                if 0 <= v && v as u64 <= Self::Value::max_value() as u64 {
-                    Ok(v as Self::Value)
-                } else {
-                    Err(Error::invalid_value(Unexpected::Signed(v as i64), &self))
+    ($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))
+            }
+        }
+    };
+
+    (nonzero $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if 0 < v && v as u64 <= $primitive::max_value() as u64 {
+                if let Some(nonzero) = Self::Value::new(v as $primitive) {
+                    return Ok(nonzero);
                 }
             }
-        )*
+            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: $ty) -> Result<Self::Value, E>
-            where
-                E: Error,
-            {
-                if v as u64 <= Self::Value::max_value() as u64 {
-                    Ok(v as Self::Value)
-                } else {
-                    Err(Error::invalid_value(Unexpected::Unsigned(v as u64), &self))
+    ($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))
+            }
+        }
+    };
+
+    (nonzero $primitive:ident $ty:ident : $visit:ident) => {
+        fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+        where
+            E: Error,
+        {
+            if v as u64 <= $primitive::max_value() as u64 {
+                if let Some(nonzero) = Self::Value::new(v as $primitive) {
+                    return Ok(nonzero);
                 }
             }
-        )*
+            Err(Error::invalid_value(Unexpected::Unsigned(v as u64), &self))
+        }
     };
 }
 
 impl_deserialize_num! {
-    i8, deserialize_i8
+    i8, NonZeroI8 cfg(not(no_num_nonzero_signed)), 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
+    i16, NonZeroI16 cfg(not(no_num_nonzero_signed)), deserialize_i16
     num_self!(i16:visit_i16);
     num_as_self!(i8:visit_i8);
     int_to_int!(i32:visit_i32 i64:visit_i64);
@@ -202,7 +292,7 @@ impl_deserialize_num! {
 }
 
 impl_deserialize_num! {
-    i32, deserialize_i32
+    i32, NonZeroI32 cfg(not(no_num_nonzero_signed)), deserialize_i32
     num_self!(i32:visit_i32);
     num_as_self!(i8:visit_i8 i16:visit_i16);
     int_to_int!(i64:visit_i64);
@@ -210,28 +300,28 @@ impl_deserialize_num! {
 }
 
 impl_deserialize_num! {
-    i64, deserialize_i64
+    i64, NonZeroI64 cfg(not(no_num_nonzero_signed)), 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
+    isize, NonZeroIsize cfg(not(no_num_nonzero_signed)), 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
+    u8, NonZeroU8, 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
+    u16, NonZeroU16, 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);
@@ -239,7 +329,7 @@ impl_deserialize_num! {
 }
 
 impl_deserialize_num! {
-    u32, deserialize_u32
+    u32, NonZeroU32, 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);
@@ -247,14 +337,14 @@ impl_deserialize_num! {
 }
 
 impl_deserialize_num! {
-    u64, deserialize_u64
+    u64, NonZeroU64, 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
+    usize, NonZeroUsize, 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);
@@ -277,42 +367,62 @@ impl_deserialize_num! {
 }
 
 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))
+    macro_rules! num_128 {
+        ($ty:ident : $visit:ident) => {
+            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+            where
+                E: Error,
+            {
+                if v as i128 >= Self::Value::min_value() as i128
+                    && v as u128 <= Self::Value::max_value() as u128
+                {
+                    Ok(v as Self::Value)
+                } else {
+                    Err(Error::invalid_value(
+                        Unexpected::Other(stringify!($ty)),
+                        &self,
+                    ))
+                }
             }
-        }
+        };
+
+        (nonzero $primitive:ident $ty:ident : $visit:ident) => {
+            fn $visit<E>(self, v: $ty) -> Result<Self::Value, E>
+            where
+                E: Error,
+            {
+                if v as i128 >= $primitive::min_value() as i128
+                    && v as u128 <= $primitive::max_value() as u128
+                {
+                    if let Some(nonzero) = Self::Value::new(v as $primitive) {
+                        Ok(nonzero)
+                    } else {
+                        Err(Error::invalid_value(Unexpected::Unsigned(0), &self))
+                    }
+                } else {
+                    Err(Error::invalid_value(
+                        Unexpected::Other(stringify!($ty)),
+                        &self,
+                    ))
+                }
+            }
+        };
     }
 
     impl_deserialize_num! {
-        u128, deserialize_u128
+        i128, NonZeroI128 cfg(not(no_num_nonzero_signed)), 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);
+        num_128!(u128:visit_u128);
+    }
+
+    impl_deserialize_num! {
+        u128, NonZeroU128, 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 visit_i128<E>(self, v: i128) -> Result<Self::Value, E>
-        where
-            E: Error,
-        {
-            if 0 <= v {
-                Ok(v as u128)
-            } else {
-                Err(Error::invalid_value(Unexpected::Other("i128"), &self))
-            }
-        }
+        num_128!(i128:visit_i128);
     }
 }
 
@@ -637,10 +747,10 @@ macro_rules! forwarded_impl {
     }
 }
 
-#[cfg(all(feature = "std", de_boxed_c_str))]
+#[cfg(all(feature = "std", not(no_de_boxed_c_str)))]
 forwarded_impl!((), Box<CStr>, CString::into_boxed_c_str);
 
-#[cfg(core_reverse)]
+#[cfg(not(no_core_reverse))]
 forwarded_impl!((T), Reverse<T>, Reverse);
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1604,7 +1714,7 @@ impl<'de> Deserialize<'de> for PathBuf {
     }
 }
 
-#[cfg(all(feature = "std", de_boxed_path))]
+#[cfg(all(feature = "std", not(no_de_boxed_path)))]
 forwarded_impl!((), Box<Path>, PathBuf::into_boxed_path);
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1685,11 +1795,7 @@ forwarded_impl!((T), Box<[T]>, Vec::into_boxed_slice);
 #[cfg(any(feature = "std", feature = "alloc"))]
 forwarded_impl!((), Box<str>, String::into_boxed_str);
 
-#[cfg(all(
-    not(de_rc_dst),
-    feature = "rc",
-    any(feature = "std", feature = "alloc")
-))]
+#[cfg(all(no_de_rc_dst, feature = "rc", any(feature = "std", feature = "alloc")))]
 forwarded_impl! {
     /// This impl requires the [`"rc"`] Cargo feature of Serde.
     ///
@@ -1701,11 +1807,7 @@ forwarded_impl! {
     (T), Arc<T>, Arc::new
 }
 
-#[cfg(all(
-    not(de_rc_dst),
-    feature = "rc",
-    any(feature = "std", feature = "alloc")
-))]
+#[cfg(all(no_de_rc_dst, feature = "rc", any(feature = "std", feature = "alloc")))]
 forwarded_impl! {
     /// This impl requires the [`"rc"`] Cargo feature of Serde.
     ///
@@ -1772,7 +1874,11 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(all(de_rc_dst, feature = "rc", any(feature = "std", feature = "alloc")))]
+#[cfg(all(
+    not(no_de_rc_dst),
+    feature = "rc",
+    any(feature = "std", feature = "alloc")
+))]
 macro_rules! box_forwarded_impl {
     (
         $(#[doc = $doc:tt])*
@@ -1793,7 +1899,11 @@ macro_rules! box_forwarded_impl {
     };
 }
 
-#[cfg(all(de_rc_dst, feature = "rc", any(feature = "std", feature = "alloc")))]
+#[cfg(all(
+    not(no_de_rc_dst),
+    feature = "rc",
+    any(feature = "std", feature = "alloc")
+))]
 box_forwarded_impl! {
     /// This impl requires the [`"rc"`] Cargo feature of Serde.
     ///
@@ -1805,7 +1915,11 @@ box_forwarded_impl! {
     Rc
 }
 
-#[cfg(all(de_rc_dst, feature = "rc", any(feature = "std", feature = "alloc")))]
+#[cfg(all(
+    not(no_de_rc_dst),
+    feature = "rc",
+    any(feature = "std", feature = "alloc")
+))]
 box_forwarded_impl! {
     /// This impl requires the [`"rc"`] Cargo feature of Serde.
     ///
@@ -1849,7 +1963,7 @@ forwarded_impl!((T), RwLock<T>, RwLock::new);
 //         secs: u64,
 //         nanos: u32,
 //     }
-#[cfg(any(core_duration, feature = "std"))]
+#[cfg(any(feature = "std", not(no_core_duration)))]
 impl<'de> Deserialize<'de> for Duration {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
@@ -2127,11 +2241,11 @@ impl<'de> Deserialize<'de> for SystemTime {
 
         const FIELDS: &'static [&'static str] = &["secs_since_epoch", "nanos_since_epoch"];
         let duration = try!(deserializer.deserialize_struct("SystemTime", FIELDS, DurationVisitor));
-        #[cfg(systemtime_checked_add)]
+        #[cfg(not(no_systemtime_checked_add))]
         let ret = UNIX_EPOCH
             .checked_add(duration)
             .ok_or_else(|| D::Error::custom("overflow deserializing SystemTime"));
-        #[cfg(not(systemtime_checked_add))]
+        #[cfg(no_systemtime_checked_add)]
         let ret = Ok(UNIX_EPOCH + duration);
         ret
     }
@@ -2167,7 +2281,7 @@ where
     }
 }
 
-#[cfg(range_inclusive)]
+#[cfg(not(no_range_inclusive))]
 impl<'de, Idx> Deserialize<'de> for RangeInclusive<Idx>
 where
     Idx: Deserialize<'de>,
@@ -2319,7 +2433,7 @@ mod range {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(any(ops_bound, collections_bound))]
+#[cfg(any(not(no_ops_bound), all(feature = "std", not(no_collections_bound))))]
 impl<'de, T> Deserialize<'de> for Bound<T>
 where
     T: Deserialize<'de>,
@@ -2427,58 +2541,6 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-macro_rules! nonzero_integers {
-    ( $( $T: ident, )+ ) => {
-        $(
-            #[cfg(num_nonzero)]
-            impl<'de> Deserialize<'de> for num::$T {
-                fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-                where
-                    D: Deserializer<'de>,
-                {
-                    let value = try!(Deserialize::deserialize(deserializer));
-                    match <num::$T>::new(value) {
-                        Some(nonzero) => Ok(nonzero),
-                        None => Err(Error::custom("expected a non-zero value")),
-                    }
-                }
-            }
-        )+
-    };
-}
-
-nonzero_integers! {
-    NonZeroU8,
-    NonZeroU16,
-    NonZeroU32,
-    NonZeroU64,
-    NonZeroUsize,
-}
-
-#[cfg(num_nonzero_signed)]
-nonzero_integers! {
-    NonZeroI8,
-    NonZeroI16,
-    NonZeroI32,
-    NonZeroI64,
-    NonZeroIsize,
-}
-
-// Currently 128-bit integers do not work on Emscripten targets so we need an
-// additional `#[cfg]`
-serde_if_integer128! {
-    nonzero_integers! {
-        NonZeroU128,
-    }
-
-    #[cfg(num_nonzero_signed)]
-    nonzero_integers! {
-        NonZeroI128,
-    }
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
 impl<'de, T, E> Deserialize<'de> for Result<T, E>
 where
     T: Deserialize<'de>,
@@ -2599,7 +2661,7 @@ where
     }
 }
 
-#[cfg(all(feature = "std", std_atomic))]
+#[cfg(all(feature = "std", not(no_std_atomic)))]
 macro_rules! atomic_impl {
     ($($ty:ident)*) => {
         $(
@@ -2615,14 +2677,14 @@ macro_rules! atomic_impl {
     };
 }
 
-#[cfg(all(feature = "std", std_atomic))]
+#[cfg(all(feature = "std", not(no_std_atomic)))]
 atomic_impl! {
     AtomicBool
     AtomicI8 AtomicI16 AtomicI32 AtomicIsize
     AtomicU8 AtomicU16 AtomicU32 AtomicUsize
 }
 
-#[cfg(all(feature = "std", std_atomic64))]
+#[cfg(all(feature = "std", not(no_std_atomic64)))]
 atomic_impl! {
     AtomicI64 AtomicU64
 }

serde/src/de/mod.rs

@@ -1213,6 +1213,20 @@ pub trait Deserializer<'de>: Sized {
     fn is_human_readable(&self) -> bool {
         true
     }
+
+    // Not public API.
+    #[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+    #[doc(hidden)]
+    fn __deserialize_content<V>(
+        self,
+        _: ::actually_private::T,
+        visitor: V,
+    ) -> Result<::private::de::Content<'de>, Self::Error>
+    where
+        V: Visitor<'de, Value = ::private::de::Content<'de>>,
+    {
+        self.deserialize_any(visitor)
+    }
 }
 
 ////////////////////////////////////////////////////////////////////////////////

serde/src/integer128.rs

@@ -66,7 +66,7 @@
 ///     ($($tt:tt)*) => {};
 /// }
 /// ```
-#[cfg(integer128)]
+#[cfg(not(no_integer128))]
 #[macro_export]
 macro_rules! serde_if_integer128 {
     ($($tt:tt)*) => {
@@ -74,7 +74,7 @@ macro_rules! serde_if_integer128 {
     };
 }
 
-#[cfg(not(integer128))]
+#[cfg(no_integer128)]
 #[macro_export]
 #[doc(hidden)]
 macro_rules! serde_if_integer128 {

serde/src/lib.rs

@@ -84,7 +84,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.131")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.134")]
 // 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
@@ -227,27 +227,27 @@ mod lib {
     #[cfg(feature = "std")]
     pub use std::time::{SystemTime, UNIX_EPOCH};
 
-    #[cfg(all(feature = "std", collections_bound))]
+    #[cfg(all(feature = "std", not(no_collections_bound), no_ops_bound))]
     pub use std::collections::Bound;
 
-    #[cfg(core_reverse)]
+    #[cfg(not(no_core_reverse))]
     pub use self::core::cmp::Reverse;
 
-    #[cfg(ops_bound)]
+    #[cfg(not(no_ops_bound))]
     pub use self::core::ops::Bound;
 
-    #[cfg(range_inclusive)]
+    #[cfg(not(no_range_inclusive))]
     pub use self::core::ops::RangeInclusive;
 
-    #[cfg(all(feature = "std", std_atomic))]
+    #[cfg(all(feature = "std", not(no_std_atomic)))]
     pub use std::sync::atomic::{
         AtomicBool, AtomicI16, AtomicI32, AtomicI8, AtomicIsize, AtomicU16, AtomicU32, AtomicU8,
         AtomicUsize, Ordering,
     };
-    #[cfg(all(feature = "std", std_atomic64))]
+    #[cfg(all(feature = "std", not(no_std_atomic64)))]
     pub use std::sync::atomic::{AtomicI64, AtomicU64};
 
-    #[cfg(any(core_duration, feature = "std"))]
+    #[cfg(any(feature = "std", not(no_core_duration)))]
     pub use self::core::time::Duration;
 }
 
@@ -295,3 +295,8 @@ extern crate serde_derive;
 #[cfg(feature = "serde_derive")]
 #[doc(hidden)]
 pub use serde_derive::*;
+
+#[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+mod actually_private {
+    pub struct T;
+}

serde/src/private/de.rs

@@ -206,6 +206,7 @@ mod content {
     use lib::*;
 
     use __private::size_hint;
+    use actually_private;
     use de::{
         self, Deserialize, DeserializeSeed, Deserializer, EnumAccess, Expected, IgnoredAny,
         MapAccess, SeqAccess, Unexpected, Visitor,
@@ -215,7 +216,7 @@ mod content {
     /// deserializing untagged enums and internally tagged enums.
     ///
     /// Not public API. Use serde-value instead.
-    #[derive(Debug)]
+    #[derive(Debug, Clone)]
     pub enum Content<'de> {
         Bool(bool),
 
@@ -294,7 +295,7 @@ mod content {
             // Untagged and internally tagged enums are only supported in
             // self-describing formats.
             let visitor = ContentVisitor { value: PhantomData };
-            deserializer.deserialize_any(visitor)
+            deserializer.__deserialize_content(actually_private::T, visitor)
         }
     }
 
@@ -1427,6 +1428,18 @@ mod content {
             drop(self);
             visitor.visit_unit()
         }
+
+        fn __deserialize_content<V>(
+            self,
+            _: actually_private::T,
+            visitor: V,
+        ) -> Result<Content<'de>, Self::Error>
+        where
+            V: Visitor<'de, Value = Content<'de>>,
+        {
+            let _ = visitor;
+            Ok(self.content)
+        }
     }
 
     impl<'de, E> ContentDeserializer<'de, E> {
@@ -2138,6 +2151,18 @@ mod content {
         {
             visitor.visit_unit()
         }
+
+        fn __deserialize_content<V>(
+            self,
+            _: actually_private::T,
+            visitor: V,
+        ) -> Result<Content<'de>, Self::Error>
+        where
+            V: Visitor<'de, Value = Content<'de>>,
+        {
+            let _ = visitor;
+            Ok(self.content.clone())
+        }
     }
 
     impl<'a, 'de, E> ContentRefDeserializer<'a, 'de, E> {

serde/src/private/mod.rs

@@ -1,6 +1,6 @@
-#[cfg(serde_derive)]
+#[cfg(not(no_serde_derive))]
 pub mod de;
-#[cfg(serde_derive)]
+#[cfg(not(no_serde_derive))]
 pub mod ser;
 
 pub mod size_hint;
@@ -22,7 +22,7 @@ pub use self::string::from_utf8_lossy;
 #[cfg(any(feature = "alloc", feature = "std"))]
 pub use lib::{ToString, Vec};
 
-#[cfg(core_try_from)]
+#[cfg(not(no_core_try_from))]
 pub use lib::convert::TryFrom;
 
 mod string {

serde/src/ser/impls.rs

@@ -239,7 +239,7 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(range_inclusive)]
+#[cfg(not(no_range_inclusive))]
 impl<Idx> Serialize for RangeInclusive<Idx>
 where
     Idx: Serialize,
@@ -258,7 +258,7 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(any(ops_bound, collections_bound))]
+#[cfg(any(not(no_ops_bound), all(feature = "std", not(no_collections_bound))))]
 impl<T> Serialize for Bound<T>
 where
     T: Serialize,
@@ -467,7 +467,7 @@ where
 macro_rules! nonzero_integers {
     ( $( $T: ident, )+ ) => {
         $(
-            #[cfg(num_nonzero)]
+            #[cfg(not(no_num_nonzero))]
             impl Serialize for num::$T {
                 fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
                 where
@@ -488,7 +488,7 @@ nonzero_integers! {
     NonZeroUsize,
 }
 
-#[cfg(num_nonzero_signed)]
+#[cfg(not(no_num_nonzero_signed))]
 nonzero_integers! {
     NonZeroI8,
     NonZeroI16,
@@ -504,7 +504,7 @@ serde_if_integer128! {
         NonZeroU128,
     }
 
-    #[cfg(num_nonzero_signed)]
+    #[cfg(not(no_num_nonzero_signed))]
     nonzero_integers! {
         NonZeroI128,
     }
@@ -591,7 +591,7 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(any(core_duration, feature = "std"))]
+#[cfg(any(feature = "std", not(no_core_duration)))]
 impl Serialize for Duration {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -890,7 +890,7 @@ where
     }
 }
 
-#[cfg(core_reverse)]
+#[cfg(not(no_core_reverse))]
 impl<T> Serialize for Reverse<T>
 where
     T: Serialize,
@@ -906,7 +906,7 @@ where
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#[cfg(all(feature = "std", std_atomic))]
+#[cfg(all(feature = "std", not(no_std_atomic)))]
 macro_rules! atomic_impl {
     ($($ty:ident)*) => {
         $(
@@ -915,6 +915,7 @@ macro_rules! atomic_impl {
                 where
                     S: Serializer,
                 {
+                    // Matches the atomic ordering used in libcore for the Debug impl
                     self.load(Ordering::SeqCst).serialize(serializer)
                 }
             }
@@ -922,14 +923,14 @@ macro_rules! atomic_impl {
     }
 }
 
-#[cfg(all(feature = "std", std_atomic))]
+#[cfg(all(feature = "std", not(no_std_atomic)))]
 atomic_impl! {
     AtomicBool
     AtomicI8 AtomicI16 AtomicI32 AtomicIsize
     AtomicU8 AtomicU16 AtomicU32 AtomicUsize
 }
 
-#[cfg(all(feature = "std", std_atomic64))]
+#[cfg(all(feature = "std", not(no_std_atomic64)))]
 atomic_impl! {
     AtomicI64 AtomicU64
 }

serde/src/ser/mod.rs

@@ -1280,13 +1280,13 @@ pub trait Serializer: Sized {
         let iter = iter.into_iter();
         let mut serializer = try!(self.serialize_seq(iterator_len_hint(&iter)));
 
-        #[cfg(iterator_try_fold)]
+        #[cfg(not(no_iterator_try_fold))]
         {
             let mut iter = iter;
             try!(iter.try_for_each(|item| serializer.serialize_element(&item)));
         }
 
-        #[cfg(not(iterator_try_fold))]
+        #[cfg(no_iterator_try_fold)]
         {
             for item in iter {
                 try!(serializer.serialize_element(&item));
@@ -1331,13 +1331,13 @@ pub trait Serializer: Sized {
         let iter = iter.into_iter();
         let mut serializer = try!(self.serialize_map(iterator_len_hint(&iter)));
 
-        #[cfg(iterator_try_fold)]
+        #[cfg(not(no_iterator_try_fold))]
         {
             let mut iter = iter;
             try!(iter.try_for_each(|(key, value)| serializer.serialize_entry(&key, &value)));
         }
 
-        #[cfg(not(iterator_try_fold))]
+        #[cfg(no_iterator_try_fold)]
         {
             for (key, value) in iter {
                 try!(serializer.serialize_entry(&key, &value));

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.131" # remember to update html_root_url
+version = "1.0.134" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 rust-version = "1.31"
 license = "MIT OR Apache-2.0"

serde_derive/src/lib.rs

@@ -13,7 +13,7 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.131")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.134")]
 #![allow(unknown_lints, bare_trait_objects)]
 // Ignored clippy lints
 #![allow(

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "1.0.131" # remember to update html_root_url
+version = "1.0.134" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 rust-version = "1.15"
 license = "MIT OR Apache-2.0"
@@ -10,7 +10,8 @@ repository = "https://github.com/serde-rs/serde"
 documentation = "https://docs.serde.rs/serde_test/"
 keywords = ["serde", "serialization"]
 readme = "crates-io.md"
-include = ["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 = { version = "1.0.60", path = "../serde" }

serde_test/build.rs

@@ -1,6 +1,6 @@
 use std::env;
 use std::process::Command;
-use std::str;
+use std::str::{self, FromStr};
 
 // 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
@@ -19,12 +19,30 @@ fn main() {
 }
 
 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 rustc = match env::var_os("RUSTC") {
+        Some(rustc) => rustc,
+        None => return None,
+    };
+
+    let output = match Command::new(rustc).arg("--version").output() {
+        Ok(output) => output,
+        Err(_) => return None,
+    };
+
+    let version = match str::from_utf8(&output.stdout) {
+        Ok(version) => version,
+        Err(_) => return None,
+    };
+
     let mut pieces = version.split('.');
     if pieces.next() != Some("rustc 1") {
         return None;
     }
-    pieces.next()?.parse().ok()
+
+    let next = match pieces.next() {
+        Some(next) => next,
+        None => return None,
+    };
+
+    u32::from_str(next).ok()
 }

serde_test/src/assert.rs

@@ -60,7 +60,7 @@ where
 /// ]);
 /// ```
 #[cfg_attr(track_caller, track_caller)]
-pub fn assert_ser_tokens<T>(value: &T, tokens: &[Token])
+pub fn assert_ser_tokens<T: ?Sized>(value: &T, tokens: &[Token])
 where
     T: Serialize,
 {
@@ -113,7 +113,7 @@ where
 /// }
 /// ```
 #[cfg_attr(track_caller, track_caller)]
-pub fn assert_ser_tokens_error<T>(value: &T, tokens: &[Token], error: &str)
+pub fn assert_ser_tokens_error<T: ?Sized>(value: &T, tokens: &[Token], error: &str)
 where
     T: Serialize,
 {

serde_test/src/lib.rs

@@ -144,7 +144,7 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.131")]
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.134")]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 // Ignored clippy lints
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp, needless_doctest_main))]

test_suite/tests/macros/mod.rs

@@ -1,93 +1,77 @@
+use serde_test::Token;
+use std::iter;
+
 macro_rules! btreeset {
     () => {
         BTreeSet::new()
     };
-    ($($value:expr),+) => {
-        {
-            let mut set = BTreeSet::new();
-            $(set.insert($value);)+
-            set
-        }
-    }
+    ($($value:expr),+) => {{
+        let mut set = BTreeSet::new();
+        $(set.insert($value);)+
+        set
+    }};
 }
 
 macro_rules! btreemap {
     () => {
         BTreeMap::new()
     };
-    ($($key:expr => $value:expr),+) => {
-        {
-            let mut map = BTreeMap::new();
-            $(map.insert($key, $value);)+
-            map
-        }
-    }
+    ($($key:expr => $value:expr),+) => {{
+        let mut map = BTreeMap::new();
+        $(map.insert($key, $value);)+
+        map
+    }};
 }
 
 macro_rules! hashset {
     () => {
         HashSet::new()
     };
-    ($($value:expr),+) => {
-        {
-            let mut set = HashSet::new();
-            $(set.insert($value);)+
-            set
-        }
-    };
-    ($hasher:ident @ $($value:expr),+) => {
-        {
-            use std::hash::BuildHasherDefault;
-            let mut set = HashSet::with_hasher(BuildHasherDefault::<$hasher>::default());
-            $(set.insert($value);)+
-            set
-        }
-    }
+    ($($value:expr),+) => {{
+        let mut set = HashSet::new();
+        $(set.insert($value);)+
+        set
+    }};
+    ($hasher:ident @ $($value:expr),+) => {{
+        use std::hash::BuildHasherDefault;
+        let mut set = HashSet::with_hasher(BuildHasherDefault::<$hasher>::default());
+        $(set.insert($value);)+
+        set
+    }};
 }
 
 macro_rules! hashmap {
     () => {
         HashMap::new()
     };
-    ($($key:expr => $value:expr),+) => {
-        {
-            let mut map = HashMap::new();
-            $(map.insert($key, $value);)+
-            map
-        }
-    };
-    ($hasher:ident @ $($key:expr => $value:expr),+) => {
-        {
-            use std::hash::BuildHasherDefault;
-            let mut map = HashMap::with_hasher(BuildHasherDefault::<$hasher>::default());
-            $(map.insert($key, $value);)+
-            map
-        }
+    ($($key:expr => $value:expr),+) => {{
+        let mut map = HashMap::new();
+        $(map.insert($key, $value);)+
+        map
+    }};
+    ($hasher:ident @ $($key:expr => $value:expr),+) => {{
+        use std::hash::BuildHasherDefault;
+        let mut map = HashMap::with_hasher(BuildHasherDefault::<$hasher>::default());
+        $(map.insert($key, $value);)+
+        map
+    }};
+}
+
+pub trait SingleTokenIntoIterator {
+    fn into_iter(self) -> iter::Once<Token>;
+}
+
+impl SingleTokenIntoIterator for Token {
+    fn into_iter(self) -> iter::Once<Token> {
+        iter::once(self)
     }
 }
 
-macro_rules! seq_impl {
-    (seq $first:expr,) => {
-        seq_impl!(seq $first)
-    };
-    ($first:expr,) => {
-        seq_impl!($first)
-    };
-    (seq $first:expr) => {
-        $first.into_iter()
-    };
-    ($first:expr) => {
-        Some($first).into_iter()
-    };
-    (seq $first:expr , $( $elem: tt)*) => {
-        $first.into_iter().chain(seq!( $($elem)* ))
-    };
-    ($first:expr , $($elem: tt)*) => {
-        Some($first).into_iter().chain(seq!( $($elem)* ))
-    }
-}
 macro_rules! seq {
-    ($($tt: tt)*) => {
-        seq_impl!($($tt)*).collect::<Vec<_>>()
-    };
+    ($($elem:expr),* $(,)?) => {{
+        use crate::macros::SingleTokenIntoIterator;
+        let mut vec = Vec::new();
+        $(<Vec<Token> as Extend<Token>>::extend(&mut vec, $elem.into_iter());)*
+        vec
+    }};
 }

test_suite/tests/test_roundtrip.rs

@@ -11,10 +11,12 @@ fn ip_addr_roundtrip() {
     assert_tokens(
         &net::IpAddr::from(*b"1234").compact(),
         &seq![
-            Token::NewtypeVariant { name: "IpAddr", variant: "V4" },
-
+            Token::NewtypeVariant {
+                name: "IpAddr",
+                variant: "V4"
+            },
             Token::Tuple { len: 4 },
-            seq b"1234".iter().map(|&b| Token::U8(b)),
+            b"1234".iter().copied().map(Token::U8),
             Token::TupleEnd,
         ],
     );
@@ -25,14 +27,14 @@ fn socket_addr_roundtrip() {
     assert_tokens(
         &net::SocketAddr::from((*b"1234567890123456", 1234)).compact(),
         &seq![
-            Token::NewtypeVariant { name: "SocketAddr", variant: "V6" },
-
+            Token::NewtypeVariant {
+                name: "SocketAddr",
+                variant: "V6"
+            },
             Token::Tuple { len: 2 },
-
             Token::Tuple { len: 16 },
-            seq b"1234567890123456".iter().map(|&b| Token::U8(b)),
+            b"1234567890123456".iter().copied().map(Token::U8),
             Token::TupleEnd,
-
             Token::U16(1234),
             Token::TupleEnd,
         ],

test_suite/tests/test_value.rs

@@ -19,7 +19,6 @@ fn test_u32_to_enum() {
     assert_eq!(E::B, e);
 }
 
-#[cfg(not(any(target_arch = "asmjs", target_arch = "wasm32")))]
 #[test]
 fn test_integer128() {
     let de_u128 = IntoDeserializer::<value::Error>::into_deserializer(1u128);