Release 1.0.115

Support flattening a Unit

.github/ISSUE_TEMPLATE/4-discussion.md

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

rustfmt.toml

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

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.111" # remember to update html_root_url and serde_derive dependency
+version = "1.0.115" # 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 = "=1.0.111", optional = true, path = "../serde_derive" }
+serde_derive = { version = "=1.0.115", optional = true, path = "../serde_derive" }
 
 [dev-dependencies]
 serde_derive = { version = "1.0", path = "../serde_derive" }

serde/build.rs

@@ -66,7 +66,7 @@ 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");
     }

serde/src/lib.rs

@@ -37,8 +37,8 @@
 //!   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.
@@ -56,6 +56,7 @@
 //! - [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.
 //!
 //! [JSON]: https://github.com/serde-rs/json
 //! [Bincode]: https://github.com/TyOverby/bincode
@@ -76,18 +77,19 @@
 //! [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
 
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.111")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.115")]
 // 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))]
@@ -95,6 +97,8 @@
 #![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,
@@ -107,6 +111,7 @@
         // things are often more readable this way
         cast_lossless,
         module_name_repetitions,
+        option_if_let_else,
         single_match_else,
         type_complexity,
         use_self,

serde/src/private/de.rs

@@ -2763,6 +2763,13 @@ 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 +2787,6 @@ where
         deserialize_string()
         deserialize_bytes()
         deserialize_byte_buf()
-        deserialize_unit()
         deserialize_unit_struct(&'static str)
         deserialize_seq()
         deserialize_tuple(usize)

serde/src/private/ser.rs

@@ -1124,7 +1124,7 @@ 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 +1243,18 @@ 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/ser/mod.rs

@@ -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 = "1.0.111" # remember to update html_root_url
+version = "1.0.115" # 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 = { version = "1.0.33", features = ["visit"] }
 
 [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/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

@@ -597,7 +597,11 @@ impl Container {
         for attr in &item.attrs {
             if attr.path.is_ident("repr") {
                 let _ = attr.parse_args_with(|input: ParseStream| {
-                    is_packed |= input.parse::<Ident>()? == "packed";
+                    while let Some(token) = input.parse()? {
+                        if let TokenTree::Ident(ident) = token {
+                            is_packed |= ident == "packed";
+                        }
+                    }
                     Ok(())
                 });
             }

serde_derive/src/lib.rs

@@ -13,18 +13,21 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.111")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.115")]
 #![allow(unknown_lints, bare_trait_objects)]
 #![deny(clippy::all, clippy::pedantic)]
 // Ignored clippy lints
 #![allow(
     clippy::cognitive_complexity,
     clippy::enum_variant_names,
+    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(
@@ -38,6 +41,7 @@
     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,
@@ -46,8 +50,6 @@
     clippy::use_self,
     clippy::wildcard_imports
 )]
-// The `quote!` macro requires deep recursion.
-#![recursion_limit = "512"]
 
 #[macro_use]
 extern crate quote;

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 = "1.0.33", default-features = false, features = ["derive", "parsing", "printing", "clone-impls"] }
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]

serde_derive_internals/lib.rs

@@ -7,7 +7,9 @@
         cognitive_complexity,
         redundant_field_names,
         trivially_copy_pass_by_ref,
-        wildcard_in_or_patterns
+        wildcard_in_or_patterns,
+        // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
+        unnested_or_patterns,
     )
 )]
 

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "1.0.111" # remember to update html_root_url
+version = "1.0.115" # 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/src/lib.rs

@@ -144,7 +144,7 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.111")]
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.115")]
 #![cfg_attr(feature = "cargo-clippy", allow(renamed_and_removed_lints))]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
 // Ignored clippy lints

test_suite/tests/expand/de_enum.expanded.rs

@@ -9,7 +9,7 @@ enum DeEnum<B, C, D> {
 }
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_SERIALIZE_FOR_DeEnum: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]
@@ -261,7 +261,7 @@ const _IMPL_SERIALIZE_FOR_DeEnum: () = {
 };
 #[doc(hidden)]
 #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-const _IMPL_DESERIALIZE_FOR_DeEnum: () = {
+const _: () = {
     #[allow(rust_2018_idioms, clippy::useless_attribute)]
     extern crate serde as _serde;
     #[automatically_derived]

test_suite/tests/expand/default_ty_param.expanded.rs

@@ -10,7 +10,7 @@ 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]
@@ -45,7 +45,7 @@ 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]

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]
@@ -110,7 +110,7 @@ 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]

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]
@@ -38,7 +38,7 @@ 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]
@@ -400,7 +400,7 @@ 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]
@@ -422,7 +422,7 @@ 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]

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]

test_suite/tests/expand/lifetimes.expanded.rs

@@ -7,7 +7,7 @@ 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]
@@ -91,7 +91,7 @@ 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]

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]
@@ -59,7 +59,7 @@ 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]

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]
@@ -51,7 +51,7 @@ 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]

test_suite/tests/expand/named_unit.expanded.rs

@@ -2,7 +2,7 @@ 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]
@@ -17,7 +17,7 @@ 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]

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]

test_suite/tests/expand/void.expanded.rs

@@ -2,7 +2,7 @@ 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]
@@ -17,7 +17,7 @@ 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]

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

@@ -1967,6 +1967,29 @@ 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)]

test_suite/tests/test_gen.rs

@@ -4,7 +4,11 @@
 
 #![deny(warnings)]
 #![cfg_attr(feature = "unstable", feature(non_ascii_idents))]
-#![allow(clippy::trivially_copy_pass_by_ref)]
+#![allow(
+    unknown_lints,
+    mixed_script_confusables,
+    clippy::trivially_copy_pass_by_ref
+)]
 
 use serde::de::DeserializeOwned;
 use serde::{Deserialize, Deserializer, Serialize, Serializer};

test_suite/tests/test_macros.rs

@@ -1878,3 +1878,31 @@ fn test_internally_tagged_newtype_variant_containing_unit_struct() {
         ],
     );
 }
+
+#[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,
+    }
+}