Release 1.0.113

Use underscore consts on Rust 1.37+

.github/workflows/ci.yml

@@ -109,6 +109,14 @@ 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_derive && cargo check
+
   alloc:
     name: Rust 1.36.0
     runs-on: ubuntu-latest

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

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

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.107" # remember to update html_root_url and serde_derive dependency
+version = "1.0.113" # 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 = "=1.0.107", optional = true, path = "../serde_derive" }
+serde_derive = { version = "=1.0.113", 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

@@ -53,6 +53,10 @@
 //!   *(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.
 //!
 //! [JSON]: https://github.com/serde-rs/json
 //! [Bincode]: https://github.com/TyOverby/bincode
@@ -71,11 +75,14 @@
 //! [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
 
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.107")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.113")]
 // 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
@@ -90,6 +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,

serde/src/private/de.rs

@@ -1562,7 +1562,7 @@ mod content {
                     other.unexpected(),
                     &"struct variant",
                 )),
-                _ => Err(de::Error::invalid_type(
+                None => Err(de::Error::invalid_type(
                     de::Unexpected::UnitVariant,
                     &"struct variant",
                 )),
@@ -2252,7 +2252,7 @@ mod content {
                     other.unexpected(),
                     &"struct variant",
                 )),
-                _ => Err(de::Error::invalid_type(
+                None => Err(de::Error::invalid_type(
                     de::Unexpected::UnitVariant,
                     &"struct variant",
                 )),

serde/src/private/ser.rs

@@ -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/fmt.rs

@@ -0,0 +1,174 @@
+use lib::*;
+use ser::{Error, Impossible, Serialize, Serializer};
+
+impl Error for fmt::Error {
+    fn custom<T: Display>(_msg: T) -> Self {
+        fmt::Error
+    }
+}
+
+macro_rules! fmt_primitives {
+    ($($f:ident: $t:ty,)*) => {
+        $(
+            fn $f(self, v: $t) -> fmt::Result {
+                Display::fmt(&v, self)
+            }
+        )*
+    };
+}
+
+/// ```edition2018
+/// use serde::Serialize;
+/// use std::fmt::{self, Display};
+///
+/// #[derive(Serialize)]
+/// #[serde(rename_all = "kebab-case")]
+/// pub enum MessageType {
+///     StartRequest,
+///     EndRequest,
+/// }
+///
+/// impl Display for MessageType {
+///     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+///         self.serialize(f)
+///     }
+/// }
+/// ```
+impl<'a, 'b> Serializer for &'a mut fmt::Formatter<'b> {
+    type Ok = ();
+    type Error = fmt::Error;
+    type SerializeSeq = Impossible<(), fmt::Error>;
+    type SerializeTuple = Impossible<(), fmt::Error>;
+    type SerializeTupleStruct = Impossible<(), fmt::Error>;
+    type SerializeTupleVariant = Impossible<(), fmt::Error>;
+    type SerializeMap = Impossible<(), fmt::Error>;
+    type SerializeStruct = Impossible<(), fmt::Error>;
+    type SerializeStructVariant = Impossible<(), fmt::Error>;
+
+    fmt_primitives! {
+        serialize_bool: bool,
+        serialize_i8: i8,
+        serialize_i16: i16,
+        serialize_i32: i32,
+        serialize_i64: i64,
+        serialize_u8: u8,
+        serialize_u16: u16,
+        serialize_u32: u32,
+        serialize_u64: u64,
+        serialize_f32: f32,
+        serialize_f64: f64,
+        serialize_char: char,
+        serialize_str: &str,
+        serialize_unit_struct: &'static str,
+    }
+
+    serde_if_integer128! {
+        fmt_primitives! {
+            serialize_i128: i128,
+            serialize_u128: u128,
+        }
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        variant: &'static str,
+    ) -> fmt::Result {
+        Display::fmt(variant, self)
+    }
+
+    fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Serialize::serialize(value, self)
+    }
+
+    fn serialize_bytes(self, _v: &[u8]) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_none(self) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_some<T: ?Sized>(self, _value: &T) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Err(fmt::Error)
+    }
+
+    fn serialize_unit(self) -> fmt::Result {
+        Err(fmt::Error)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T,
+    ) -> fmt::Result
+    where
+        T: Serialize,
+    {
+        Err(fmt::Error)
+    }
+
+    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple(self, _len: usize) -> Result<Self::SerializeTuple, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleStruct, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleVariant, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStruct, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant, fmt::Error> {
+        Err(fmt::Error)
+    }
+
+    fn collect_str<T: ?Sized>(self, value: &T) -> fmt::Result
+    where
+        T: Display,
+    {
+        Display::fmt(value, self)
+    }
+}

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()));

serde/src/ser/mod.rs

@@ -109,6 +109,7 @@
 
 use lib::*;
 
+mod fmt;
 mod impls;
 mod impossible;
 

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.107" # remember to update html_root_url
+version = "1.0.113" # 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 = []

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

@@ -5,7 +5,7 @@ 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;
 
@@ -114,7 +114,7 @@ pub fn with_bound(
     }
     impl<'ast> Visit<'ast> for 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);

serde_derive/src/de.rs

@@ -8,7 +8,7 @@ use bound;
 use dummy;
 use fragment::{Expr, Fragment, Match, Stmts};
 use internals::ast::{Container, Data, Field, Style, Variant};
-use internals::{attr, Ctxt, Derive};
+use internals::{attr, ungroup, Ctxt, Derive};
 use pretend;
 
 use std::collections::BTreeSet;
@@ -77,7 +77,7 @@ fn precondition(cx: &Ctxt, cont: &Container) {
 fn precondition_sized(cx: &Ctxt, cont: &Container) {
     if let Data::Struct(_, fields) = &cont.data {
         if let Some(last) = fields.last() {
-            if let syn::Type::Slice(_) = *last.ty {
+            if let syn::Type::Slice(_) = ungroup(last.ty) {
                 cx.error_spanned_by(
                     cont.original,
                     "cannot deserialize a dynamically sized struct",
@@ -1377,39 +1377,44 @@ fn deserialize_adjacently_tagged_enum(
         }
     };
 
-    fn is_unit(variant: &Variant) -> bool {
-        match variant.style {
-            Style::Unit => true,
-            Style::Struct | Style::Tuple | Style::Newtype => false,
-        }
-    }
-
     let mut missing_content = quote! {
         _serde::export::Err(<__A::Error as _serde::de::Error>::missing_field(#content))
     };
-    if variants.iter().any(is_unit) {
-        let fallthrough = if variants.iter().all(is_unit) {
-            None
-        } else {
-            Some(quote! {
-                _ => #missing_content
-            })
-        };
-        let arms = variants
-            .iter()
-            .enumerate()
-            .filter(|&(_, variant)| !variant.attrs.skip_deserializing() && is_unit(variant))
-            .map(|(i, variant)| {
-                let variant_index = field_i(i);
-                let variant_ident = &variant.ident;
-                quote! {
-                    __Field::#variant_index => _serde::export::Ok(#this::#variant_ident),
+    let mut missing_content_fallthrough = quote!();
+    let missing_content_arms = variants
+        .iter()
+        .enumerate()
+        .filter(|&(_, variant)| !variant.attrs.skip_deserializing())
+        .filter_map(|(i, variant)| {
+            let variant_index = field_i(i);
+            let variant_ident = &variant.ident;
+
+            let arm = match variant.style {
+                Style::Unit => quote! {
+                    _serde::export::Ok(#this::#variant_ident)
+                },
+                Style::Newtype if variant.attrs.deserialize_with().is_none() => {
+                    let span = variant.original.span();
+                    let func = quote_spanned!(span=> _serde::private::de::missing_field);
+                    quote! {
+                        #func(#content).map(#this::#variant_ident)
+                    }
                 }
-            });
+                _ => {
+                    missing_content_fallthrough = quote!(_ => #missing_content);
+                    return None;
+                }
+            };
+            Some(quote! {
+                __Field::#variant_index => #arm,
+            })
+        })
+        .collect::<Vec<_>>();
+    if !missing_content_arms.is_empty() {
         missing_content = quote! {
             match __field {
-                #(#arms)*
-                #fallthrough
+                #(#missing_content_arms)*
+                #missing_content_fallthrough
             }
         };
     }

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

@@ -1,5 +1,5 @@
 use internals::symbol::*;
-use internals::Ctxt;
+use internals::{ungroup, Ctxt};
 use proc_macro2::{Group, Span, TokenStream, TokenTree};
 use quote::ToTokens;
 use std::borrow::Cow;
@@ -222,6 +222,7 @@ pub struct Container {
     identifier: Identifier,
     has_flatten: bool,
     serde_path: Option<syn::Path>,
+    is_packed: bool,
 }
 
 /// Styles of representing an enum.
@@ -592,6 +593,16 @@ 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| {
+                    is_packed |= input.parse::<Ident>()? == "packed";
+                    Ok(())
+                });
+            }
+        }
+
         Container {
             name: Name::from_attrs(unraw(&item.ident), ser_name, de_name, None),
             transparent: transparent.get(),
@@ -611,6 +622,7 @@ impl Container {
             identifier: decide_identifier(cx, item, field_identifier, variant_identifier),
             has_flatten: false,
             serde_path: serde_path.get(),
+            is_packed,
         }
     }
 
@@ -662,6 +674,10 @@ impl Container {
         self.remote.as_ref()
     }
 
+    pub fn is_packed(&self) -> bool {
+        self.is_packed
+    }
+
     pub fn identifier(&self) -> Identifier {
         self.identifier
     }
@@ -1721,7 +1737,7 @@ 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 +1764,7 @@ 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 +1811,7 @@ 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 +1822,14 @@ 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,
     }

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

@@ -8,8 +8,17 @@ mod case;
 mod check;
 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/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/1.0.107")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.113")]
 #![allow(unknown_lints, bare_trait_objects)]
 #![deny(clippy::all, clippy::pedantic)]
 // Ignored clippy lints
@@ -24,7 +24,9 @@
     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(

serde_derive/src/ser.rs

@@ -87,6 +87,9 @@ struct Parameters {
 
     /// Type has a `serde(remote = "...")` attribute.
     is_remote: bool,
+
+    /// Type has a repr(packed) attribute.
+    is_packed: bool,
 }
 
 impl Parameters {
@@ -103,6 +106,8 @@ impl Parameters {
             None => cont.ident.clone().into(),
         };
 
+        let is_packed = cont.attrs.is_packed();
+
         let generics = build_generics(cont);
 
         Parameters {
@@ -110,6 +115,7 @@ impl Parameters {
             this,
             generics,
             is_remote,
+            is_packed,
         }
     }
 
@@ -1238,9 +1244,19 @@ 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))
         }

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"

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 = "1.0.107" # remember to update html_root_url
+version = "1.0.113" # 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/1.0.107")]
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.113")]
 #![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/test_gen.rs

@@ -701,6 +701,24 @@ 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);
 }
 
 //////////////////////////////////////////////////////////////////////////

test_suite/tests/test_macros.rs

@@ -1145,6 +1145,20 @@ 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),