Release 1.0.45

Pretend remote derives are not dead code

.travis.yml

@@ -5,6 +5,7 @@ cache: cargo
 # run builds for all the trains (and more)
 rust:
   - 1.13.0
+  - 1.15.0
   - stable
   - beta
   - nightly

serde/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "1.0.41" # remember to update html_root_url
+version = "1.0.45" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"

serde/src/de/mod.rs

@@ -196,6 +196,7 @@ macro_rules! declare_error_trait {
             /// For example if we try to deserialize a String out of a JSON file
             /// containing an integer, the unexpected type is the integer and the
             /// expected type is the string.
+            #[cold]
             fn invalid_type(unexp: Unexpected, exp: &Expected) -> Self {
                 Error::custom(format_args!("invalid type: {}, expected {}", unexp, exp))
             }
@@ -213,6 +214,7 @@ macro_rules! declare_error_trait {
             /// For example if we try to deserialize a String out of some binary data
             /// that is not valid UTF-8, the unexpected value is the bytes and the
             /// expected value is a string.
+            #[cold]
             fn invalid_value(unexp: Unexpected, exp: &Expected) -> Self {
                 Error::custom(format_args!("invalid value: {}, expected {}", unexp, exp))
             }
@@ -226,12 +228,14 @@ macro_rules! declare_error_trait {
             /// The `exp` argument provides information about what data was being
             /// expected. For example `exp` might say that a tuple of size 6 was
             /// expected.
+            #[cold]
             fn invalid_length(len: usize, exp: &Expected) -> Self {
                 Error::custom(format_args!("invalid length {}, expected {}", len, exp))
             }
 
             /// Raised when a `Deserialize` enum type received a variant with an
             /// unrecognized name.
+            #[cold]
             fn unknown_variant(variant: &str, expected: &'static [&'static str]) -> Self {
                 if expected.is_empty() {
                     Error::custom(format_args!("unknown variant `{}`, there are no variants",
@@ -245,6 +249,7 @@ macro_rules! declare_error_trait {
 
             /// Raised when a `Deserialize` struct type received a field with an
             /// unrecognized name.
+            #[cold]
             fn unknown_field(field: &str, expected: &'static [&'static str]) -> Self {
                 if expected.is_empty() {
                     Error::custom(format_args!("unknown field `{}`, there are no fields",
@@ -259,12 +264,14 @@ macro_rules! declare_error_trait {
             /// Raised when a `Deserialize` struct type expected to receive a required
             /// field with a particular name but that field was not present in the
             /// input.
+            #[cold]
             fn missing_field(field: &'static str) -> Self {
                 Error::custom(format_args!("missing field `{}`", field))
             }
 
             /// Raised when a `Deserialize` struct type received more than one of the
             /// same field.
+            #[cold]
             fn duplicate_field(field: &'static str) -> Self {
                 Error::custom(format_args!("duplicate field `{}`", field))
             }

serde/src/de/value.rs

@@ -58,6 +58,7 @@ type ErrorImpl = ();
 
 impl de::Error for Error {
     #[cfg(any(feature = "std", feature = "alloc"))]
+    #[cold]
     fn custom<T>(msg: T) -> Self
     where
         T: Display,
@@ -68,6 +69,7 @@ impl de::Error for Error {
     }
 
     #[cfg(not(any(feature = "std", feature = "alloc")))]
+    #[cold]
     fn custom<T>(msg: T) -> Self
     where
         T: Display,
@@ -78,6 +80,7 @@ impl de::Error for Error {
 }
 
 impl ser::Error for Error {
+    #[cold]
     fn custom<T>(msg: T) -> Self
     where
         T: Display,

serde/src/export.rs

@@ -16,6 +16,9 @@ pub use lib::result::Result::{self, Err, Ok};
 
 pub use self::string::from_utf8_lossy;
 
+#[cfg(any(feature = "alloc", feature = "std"))]
+pub use lib::Vec;
+
 mod string {
     use lib::*;
 

serde/src/lib.rs

@@ -79,7 +79,7 @@
 ////////////////////////////////////////////////////////////////////////////////
 
 // Serde types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/serde/1.0.41")]
+#![doc(html_root_url = "https://docs.rs/serde/1.0.45")]
 // 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

serde/src/private/de.rs

@@ -277,6 +277,7 @@ mod content {
             }
         }
 
+        #[cold]
         fn unexpected(&self) -> Unexpected {
             match *self {
                 Content::Bool(b) => Unexpected::Bool(b),
@@ -1309,7 +1310,10 @@ mod content {
         where
             V: Visitor<'de>,
         {
-            visitor.visit_newtype_struct(self)
+            match self.content {
+                Content::Newtype(v) => visitor.visit_newtype_struct(ContentDeserializer::new(*v)),
+                _ => visitor.visit_newtype_struct(self),
+            }
         }
 
         fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>
@@ -2000,7 +2004,12 @@ mod content {
         where
             V: Visitor<'de>,
         {
-            visitor.visit_newtype_struct(self)
+            match *self.content {
+                Content::Newtype(ref v) => {
+                    visitor.visit_newtype_struct(ContentRefDeserializer::new(v))
+                }
+                _ => visitor.visit_newtype_struct(self),
+            }
         }
 
         fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>

serde_derive/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_derive"
-version = "1.0.41" # remember to update html_root_url
+version = "1.0.45" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros 1.1 implementation of #[derive(Serialize, Deserialize)]"
@@ -24,7 +24,7 @@ proc-macro = true
 
 [dependencies]
 proc-macro2 = "0.3"
-quote = "0.5"
+quote = "0.5.2"
 serde_derive_internals = { version = "=0.23.1", default-features = false, path = "../serde_derive_internals" }
 syn = { version = "0.13", features = ["visit"] }
 

serde_derive/src/de.rs

@@ -16,6 +16,8 @@ use bound;
 use fragment::{Expr, Fragment, Match, Stmts};
 use internals::ast::{Container, Data, Field, Style, Variant};
 use internals::{self, attr};
+use pretend;
+use try;
 
 use std::collections::BTreeSet;
 
@@ -36,12 +38,13 @@ pub fn expand_derive_deserialize(input: &syn::DeriveInput) -> Result<Tokens, Str
 
     let impl_block = if let Some(remote) = cont.attrs.remote() {
         let vis = &input.vis;
-        let fun = quote_spanned!(Span::call_site()=> deserialize);
+        let used = pretend::pretend_used(&cont);
         quote! {
             impl #de_impl_generics #ident #ty_generics #where_clause {
-                #vis fn #fun<__D>(__deserializer: __D) -> _serde::export::Result<#remote #ty_generics, __D::Error>
+                #vis fn deserialize<__D>(__deserializer: __D) -> _serde::export::Result<#remote #ty_generics, __D::Error>
                     where __D: _serde::Deserializer<#delife>
                 {
+                    #used
                     #body
                 }
             }
@@ -63,10 +66,12 @@ pub fn expand_derive_deserialize(input: &syn::DeriveInput) -> Result<Tokens, Str
         }
     };
 
+    let try_replacement = try::replacement();
     let generated = quote! {
         #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
         const #dummy_const: () = {
             extern crate serde as _serde;
+            #try_replacement
             #impl_block
         };
     };
@@ -583,11 +588,11 @@ fn deserialize_seq(
 
     let mut result = if is_struct {
         let names = fields.iter().map(|f| &f.ident);
-        quote_spanned! {Span::call_site()=>
+        quote! {
             #type_path { #( #names: #vars ),* }
         }
     } else {
-        quote_spanned! {Span::call_site()=>
+        quote! {
             #type_path ( #(#vars),* )
         }
     };
@@ -649,11 +654,10 @@ fn deserialize_seq_in_place(
                 })
             });
 
-            let dot = quote_spanned!(Span::call_site()=> .);
             if field.attrs.skip_deserializing() {
                 let default = Expr(expr_is_missing(field, cattrs));
                 quote! {
-                    self.place #dot #field_name = #default;
+                    self.place.#field_name = #default;
                 }
             } else {
                 let return_invalid_length = quote! {
@@ -663,7 +667,7 @@ fn deserialize_seq_in_place(
                     None => {
                         quote! {
                             if let _serde::export::None = try!(_serde::de::SeqAccess::next_element_seed(&mut __seq,
-                                _serde::private::de::InPlaceSeed(&mut self.place #dot #field_name)))
+                                _serde::private::de::InPlaceSeed(&mut self.place.#field_name)))
                             {
                                 #return_invalid_length
                             }
@@ -676,7 +680,7 @@ fn deserialize_seq_in_place(
                             #wrapper
                             match try!(_serde::de::SeqAccess::next_element::<#wrapper_ty>(&mut __seq)) {
                                 _serde::export::Some(__wrap) => {
-                                    self.place #dot #field_name = __wrap.value;
+                                    self.place.#field_name = __wrap.value;
                                 }
                                 _serde::export::None => {
                                     #return_invalid_length
@@ -732,7 +736,7 @@ fn deserialize_newtype_struct(type_path: &Tokens, params: &Parameters, field: &F
         }
     };
 
-    let mut result = quote_spanned!(Span::call_site()=> #type_path(#value));
+    let mut result = quote!(#type_path(__field0));
     if params.has_getter {
         let this = &params.this;
         result = quote! {
@@ -745,6 +749,7 @@ fn deserialize_newtype_struct(type_path: &Tokens, params: &Parameters, field: &F
         fn visit_newtype_struct<__E>(self, __e: __E) -> _serde::export::Result<Self::Value, __E::Error>
             where __E: _serde::Deserializer<#delife>
         {
+            let __field0 = #value;
             _serde::export::Ok(#result)
         }
     }
@@ -757,13 +762,12 @@ fn deserialize_newtype_struct_in_place(params: &Parameters, field: &Field) -> To
 
     let delife = params.borrowed.de_lifetime();
 
-    let elem = quote_spanned!(Span::call_site()=> .0);
     quote! {
         #[inline]
         fn visit_newtype_struct<__E>(self, __e: __E) -> _serde::export::Result<Self::Value, __E::Error>
             where __E: _serde::Deserializer<#delife>
         {
-            _serde::Deserialize::deserialize_in_place(__e, &mut self.place #elem)
+            _serde::Deserialize::deserialize_in_place(__e, &mut self.place.0)
         }
     }
 }
@@ -1625,12 +1629,13 @@ fn deserialize_untagged_variant(
             let type_name = params.type_name();
             let variant_name = variant.ident.as_ref();
             quote_expr! {
-                _serde::export::Result::map(
+                match _serde::Deserializer::deserialize_any(
-                    _serde::Deserializer::deserialize_any(
+                    #deserializer,
-                        #deserializer,
+                    _serde::private::de::UntaggedUnitVisitor::new(#type_name, #variant_name)
-                        _serde::private::de::UntaggedUnitVisitor::new(#type_name, #variant_name)
+                ) {
-                    ),
+                    _serde::export::Ok(()) => _serde::export::Ok(#this::#variant_ident),
-                    |()| #this::#variant_ident)
+                    _serde::export::Err(__err) => _serde::export::Err(__err),
+                }
             }
         }
         Style::Newtype => deserialize_untagged_newtype_variant(
@@ -1939,82 +1944,82 @@ fn deserialize_identifier(
     let fallthrough_msg = format!("{} index 0 <= i < {}", index_expecting, fields.len());
     let visit_other = if collect_other_fields {
         quote! {
-            fn visit_bool<__E>(self, __value: bool) -> Result<Self::Value, __E>
+            fn visit_bool<__E>(self, __value: bool) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::Bool(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::Bool(__value)))
             }
 
-            fn visit_i8<__E>(self, __value: i8) -> Result<Self::Value, __E>
+            fn visit_i8<__E>(self, __value: i8) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::I8(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::I8(__value)))
             }
 
-            fn visit_i16<__E>(self, __value: i16) -> Result<Self::Value, __E>
+            fn visit_i16<__E>(self, __value: i16) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::I16(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::I16(__value)))
             }
 
-            fn visit_i32<__E>(self, __value: i32) -> Result<Self::Value, __E>
+            fn visit_i32<__E>(self, __value: i32) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::I32(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::I32(__value)))
             }
 
-            fn visit_i64<__E>(self, __value: i64) -> Result<Self::Value, __E>
+            fn visit_i64<__E>(self, __value: i64) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::I64(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::I64(__value)))
             }
 
-            fn visit_u8<__E>(self, __value: u8) -> Result<Self::Value, __E>
+            fn visit_u8<__E>(self, __value: u8) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::U8(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::U8(__value)))
             }
 
-            fn visit_u16<__E>(self, __value: u16) -> Result<Self::Value, __E>
+            fn visit_u16<__E>(self, __value: u16) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::U16(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::U16(__value)))
             }
 
-            fn visit_u32<__E>(self, __value: u32) -> Result<Self::Value, __E>
+            fn visit_u32<__E>(self, __value: u32) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::U32(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::U32(__value)))
             }
 
-            fn visit_u64<__E>(self, __value: u64) -> Result<Self::Value, __E>
+            fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::U64(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::U64(__value)))
             }
 
-            fn visit_f32<__E>(self, __value: f32) -> Result<Self::Value, __E>
+            fn visit_f32<__E>(self, __value: f32) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::F32(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::F32(__value)))
             }
 
-            fn visit_f64<__E>(self, __value: f64) -> Result<Self::Value, __E>
+            fn visit_f64<__E>(self, __value: f64) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::F64(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::F64(__value)))
             }
 
-            fn visit_char<__E>(self, __value: char) -> Result<Self::Value, __E>
+            fn visit_char<__E>(self, __value: char) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::Char(__value)))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::Char(__value)))
             }
 
-            fn visit_unit<__E>(self) -> Result<Self::Value, __E>
+            fn visit_unit<__E>(self) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
-                Ok(__Field::__other(_serde::private::de::Content::Unit))
+                _serde::export::Ok(__Field::__other(_serde::private::de::Content::Unit))
             }
 
             fn visit_borrowed_str<__E>(self, __value: &'de str) -> _serde::export::Result<Self::Value, __E>
@@ -2177,7 +2182,7 @@ fn deserialize_map(
     // Collect contents for flatten fields into a buffer
     let let_collect = if cattrs.has_flatten() {
         Some(quote! {
-            let mut __collect = Vec::<Option<(
+            let mut __collect = _serde::export::Vec::<_serde::export::Option<(
                 _serde::private::de::Content,
                 _serde::private::de::Content
             )>>::new();
@@ -2225,7 +2230,7 @@ fn deserialize_map(
     let ignored_arm = if cattrs.has_flatten() {
         Some(quote! {
             __Field::__other(__name) => {
-                __collect.push(Some((
+                __collect.push(_serde::export::Some((
                     __name,
                     try!(_serde::de::MapAccess::next_value(&mut __map)))));
             }
@@ -2277,8 +2282,12 @@ fn deserialize_map(
         .filter(|&&(field, _)| field.attrs.flatten())
         .map(|&(field, ref name)| {
             let field_ty = field.ty;
+            let func = match field.attrs.deserialize_with() {
+                None => quote!(_serde::de::Deserialize::deserialize),
+                Some(path) => quote!(#path),
+            };
             quote! {
-                let #name: #field_ty = try!(_serde::de::Deserialize::deserialize(
+                let #name: #field_ty = try!(#func(
                     _serde::private::de::FlatMapDeserializer(
                         &mut __collect,
                         _serde::export::PhantomData)));
@@ -2287,8 +2296,8 @@ fn deserialize_map(
 
     let collected_deny_unknown_fields = if cattrs.has_flatten() && cattrs.deny_unknown_fields() {
         Some(quote! {
-            if let Some(Some((__key, _))) = __collect.into_iter().filter(|x| x.is_some()).next() {
+            if let _serde::export::Some(_serde::export::Some((__key, _))) = __collect.into_iter().filter(|x| x.is_some()).next() {
-                if let Some(__key) = __key.as_str() {
+                if let _serde::export::Some(__key) = __key.as_str() {
                     return _serde::export::Err(
                         _serde::de::Error::custom(format_args!("unknown field `{}`", &__key)));
                 } else {
@@ -2305,9 +2314,9 @@ fn deserialize_map(
         let ident = field.ident.expect("struct contains unnamed fields");
         if field.attrs.skip_deserializing() {
             let value = Expr(expr_is_missing(field, cattrs));
-            quote_spanned!(Span::call_site()=> #ident: #value)
+            quote!(#ident: #value)
         } else {
-            quote_spanned!(Span::call_site()=> #ident: #name)
+            quote!(#ident: #name)
         }
     });
 
@@ -2325,7 +2334,7 @@ fn deserialize_map(
         }
     };
 
-    let mut result = quote_spanned!(Span::call_site()=> #struct_path { #(#result),* });
+    let mut result = quote!(#struct_path { #(#result),* });
     if params.has_getter {
         let this = &params.this;
         result = quote! {

serde_derive/src/lib.rs

@@ -22,7 +22,7 @@
 //!
 //! [https://serde.rs/derive.html]: https://serde.rs/derive.html
 
-#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.41")]
+#![doc(html_root_url = "https://docs.rs/serde_derive/1.0.45")]
 #![cfg_attr(
     feature = "cargo-clippy",
     allow(enum_variant_names, redundant_field_names, too_many_arguments, used_underscore_binding)
@@ -43,21 +43,15 @@ extern crate proc_macro2;
 use proc_macro::TokenStream;
 use syn::DeriveInput;
 
-// Quote's default is def_site but it appears call_site is likely to stabilize
-// before def_site. Thus we try to use only call_site.
-macro_rules! quote {
-    ($($tt:tt)*) => {
-        quote_spanned!($crate::proc_macro2::Span::call_site()=> $($tt)*)
-    }
-}
-
 #[macro_use]
 mod bound;
 #[macro_use]
 mod fragment;
 
 mod de;
+mod pretend;
 mod ser;
+mod try;
 
 #[proc_macro_derive(Serialize, attributes(serde))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {

serde_derive/src/pretend.rs

@@ -0,0 +1,145 @@
+use proc_macro2::Span;
+use quote::Tokens;
+use syn::Ident;
+
+use internals::ast::{Container, Data, Field, Style};
+
+// Suppress dead_code warnings that would otherwise appear when using a remote
+// derive. Other than this pretend code, a struct annotated with remote derive
+// never has its fields referenced and an enum annotated with remote derive
+// never has its variants constructed.
+//
+//     warning: field is never used: `i`
+//      --> src/main.rs:4:20
+//       |
+//     4 | struct StructDef { i: i32 }
+//       |                    ^^^^^^
+//
+//     warning: variant is never constructed: `V`
+//      --> src/main.rs:8:16
+//       |
+//     8 | enum EnumDef { V }
+//       |                ^
+//
+pub fn pretend_used(cont: &Container) -> Tokens {
+    let pretend_fields = pretend_fields_used(cont);
+    let pretend_variants = pretend_variants_used(cont);
+
+    quote! {
+        #pretend_fields
+        #pretend_variants
+    }
+}
+
+// For structs with named fields, expands to:
+//
+//     match None::<T> {
+//         Some(T { a: ref __v0, b: ref __v1 }) => {}
+//         _ => {}
+//     }
+//
+// For enums, expands to the following but only including struct variants:
+//
+//     match None::<T> {
+//         Some(T::A { a: ref __v0 }) => {}
+//         Some(T::B { b: ref __v0 }) => {}
+//         _ => {}
+//     }
+//
+// The `ref` is important in case the user has written a Drop impl on their
+// type. Rust does not allow destructuring a struct or enum that has a Drop
+// impl.
+fn pretend_fields_used(cont: &Container) -> Tokens {
+    let type_ident = cont.ident;
+    let (_, ty_generics, _) = cont.generics.split_for_impl();
+
+    let patterns = match cont.data {
+        Data::Enum(ref variants) => {
+            variants.iter()
+                .filter_map(|variant| match variant.style {
+                    Style::Struct => {
+                        let variant_ident = variant.ident;
+                        let pat = struct_pattern(&variant.fields);
+                        Some(quote!(#type_ident::#variant_ident #pat))
+                    }
+                    _ => None,
+                })
+                .collect::<Vec<_>>()
+        }
+        Data::Struct(Style::Struct, ref fields) => {
+            let pat = struct_pattern(fields);
+            vec![quote!(#type_ident #pat)]
+        }
+        Data::Struct(_, _) => {
+            return quote!();
+        }
+    };
+
+    quote! {
+        match _serde::export::None::<#type_ident #ty_generics> {
+            #(
+                _serde::export::Some(#patterns) => {}
+            )*
+            _ => {}
+        }
+    }
+}
+
+// Expands to one of these per enum variant:
+//
+//     match None {
+//         Some((__v0, __v1,)) => {
+//             let _ = E::V { a: __v0, b: __v1 };
+//         }
+//         _ => {}
+//     }
+//
+fn pretend_variants_used(cont: &Container) -> Tokens {
+    let variants = match cont.data {
+        Data::Enum(ref variants) => variants,
+        Data::Struct(_, _) => {
+            return quote!();
+        }
+    };
+
+    let type_ident = cont.ident;
+    let (_, ty_generics, _) = cont.generics.split_for_impl();
+    let turbofish = ty_generics.as_turbofish();
+
+    let cases = variants.iter()
+        .map(|variant| {
+            let variant_ident = variant.ident;
+            let ref placeholders = (0..variant.fields.len())
+                .map(|i| Ident::new(&format!("__v{}", i), Span::call_site()))
+                .collect::<Vec<_>>();
+
+            let pat = match variant.style {
+                Style::Struct => {
+                    let names = variant.fields.iter().map(|field| field.ident);
+                    quote!({ #(#names: #placeholders),* })
+                }
+                Style::Tuple | Style::Newtype => {
+                    quote!(( #(#placeholders),* ))
+                }
+                Style::Unit => quote!(),
+            };
+
+            quote! {
+                match _serde::export::None {
+                    _serde::export::Some((#(#placeholders,)*)) => {
+                        let _ = #type_ident::#variant_ident #turbofish #pat;
+                    }
+                    _ => {}
+                }
+            }
+        });
+
+    quote!(#(#cases)*)
+}
+
+fn struct_pattern(fields: &[Field]) -> Tokens {
+    let names = fields.iter().map(|field| field.ident);
+    let placeholders = (0..fields.len())
+        .map(|i| Ident::new(&format!("__v{}", i), Span::call_site()));
+    quote!({ #(#names: ref #placeholders),* })
+}

serde_derive/src/ser.rs

@@ -15,6 +15,8 @@ use bound;
 use fragment::{Fragment, Match, Stmts};
 use internals::ast::{Container, Data, Field, Style, Variant};
 use internals::{attr, Ctxt};
+use pretend;
+use try;
 
 use std::u32;
 
@@ -32,12 +34,13 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<Tokens, Strin
 
     let impl_block = if let Some(remote) = cont.attrs.remote() {
         let vis = &input.vis;
-        let fun = quote_spanned!(Span::call_site()=> serialize);
+        let used = pretend::pretend_used(&cont);
         quote! {
             impl #impl_generics #ident #ty_generics #where_clause {
-                #vis fn #fun<__S>(__self: &#remote #ty_generics, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
+                #vis fn serialize<__S>(__self: &#remote #ty_generics, __serializer: __S) -> _serde::export::Result<__S::Ok, __S::Error>
                     where __S: _serde::Serializer
                 {
+                    #used
                     #body
                 }
             }
@@ -55,10 +58,12 @@ pub fn expand_derive_serialize(input: &syn::DeriveInput) -> Result<Tokens, Strin
         }
     };
 
+    let try_replacement = try::replacement();
     let generated = quote! {
         #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
         const #dummy_const: () = {
             extern crate serde as _serde;
+            #try_replacement
             #impl_block
         };
     };
@@ -594,9 +599,15 @@ fn serialize_adjacently_tagged_variant(
                     field_expr = wrap_serialize_field_with(params, field.ty, path, &field_expr);
                 }
 
-                quote_expr! {
+                return quote_block! {
-                    _serde::Serialize::serialize(#field_expr, __serializer)
+                    let mut __struct = try!(_serde::Serializer::serialize_struct(
-                }
+                        __serializer, #type_name, 2));
+                    try!(_serde::ser::SerializeStruct::serialize_field(
+                        &mut __struct, #tag, #variant_name));
+                    try!(_serde::ser::SerializeStruct::serialize_field(
+                        &mut __struct, #content, #field_expr));
+                    _serde::ser::SerializeStruct::end(__struct)
+                };
             }
             Style::Tuple => {
                 serialize_tuple_variant(TupleVariant::Untagged, params, &variant.fields)
@@ -1056,9 +1067,9 @@ fn mut_if(is_mut: bool) -> Option<Tokens> {
 fn get_member(params: &Parameters, field: &Field, member: &Member) -> Tokens {
     let self_var = &params.self_var;
     match (params.is_remote, field.attrs.getter()) {
-        (false, None) => quote_spanned!(Span::call_site()=> &#self_var.#member),
+        (false, None) => quote!(&#self_var.#member),
         (true, None) => {
-            let inner = quote_spanned!(Span::call_site()=> &#self_var.#member);
+            let inner = quote!(&#self_var.#member);
             let ty = field.ty;
             quote!(_serde::private::ser::constrain::<#ty>(#inner))
         }

serde_derive/src/try.rs

@@ -0,0 +1,25 @@
+use proc_macro2::{Op, Spacing};
+use quote::Tokens;
+
+// None of our generated code requires the `From::from` error conversion
+// performed by the standard library's `try!` macro. With this simplified macro
+// we see a significant improvement in type checking and borrow checking time of
+// the generated code and a slight improvement in binary size.
+pub fn replacement() -> Tokens {
+    // Cannot pass `$expr` to `quote!` prior to Rust 1.17.0 so interpolate it.
+    let dollar = Op::new('$', Spacing::Alone);
+
+    quote! {
+        #[allow(unused_macros)]
+        macro_rules! try {
+            (#dollar __expr:expr) => {
+                match #dollar __expr {
+                    _serde::export::Ok(__val) => __val,
+                    _serde::export::Err(__err) => {
+                        return _serde::export::Err(__err);
+                    }
+                }
+            }
+        }
+    }
+}

serde_test/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "serde_test"
-version = "1.0.41" # remember to update html_root_url
+version = "1.0.45" # remember to update html_root_url
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>", "David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Token De/Serializer for testing De/Serialize implementations"

serde_test/src/lib.rs

@@ -155,7 +155,7 @@
 //! # }
 //! ```
 
-#![doc(html_root_url = "https://docs.rs/serde_test/1.0.41")]
+#![doc(html_root_url = "https://docs.rs/serde_test/1.0.45")]
 #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
 // Whitelisted clippy lints
 #![cfg_attr(feature = "cargo-clippy", allow(float_cmp))]

test_suite/tests/bytes/mod.rs

@@ -1,8 +1,9 @@
-use serde::de::{Deserializer, Visitor, SeqAccess, Error};
+use serde::de::{Deserializer, Error, SeqAccess, Visitor};
 use std::fmt;
 
 pub fn deserialize<'de, D>(deserializer: D) -> Result<Vec<u8>, D::Error>
-    where D: Deserializer<'de>
+where
+    D: Deserializer<'de>,
 {
     deserializer.deserialize_byte_buf(ByteBufVisitor)
 }
@@ -17,7 +18,8 @@ impl<'de> Visitor<'de> for ByteBufVisitor {
     }
 
     fn visit_seq<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
-        where V: SeqAccess<'de>
+    where
+        V: SeqAccess<'de>,
     {
         let mut values = Vec::new();
         while let Some(value) = try!(visitor.next_element()) {
@@ -27,25 +29,29 @@ impl<'de> Visitor<'de> for ByteBufVisitor {
     }
 
     fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
-        where E: Error
+    where
+        E: Error,
     {
         Ok(v.to_vec())
     }
 
     fn visit_byte_buf<E>(self, v: Vec<u8>) -> Result<Self::Value, E>
-        where E: Error
+    where
+        E: Error,
     {
         Ok(v)
     }
 
     fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
-        where E: Error
+    where
+        E: Error,
     {
         Ok(v.as_bytes().to_vec())
     }
 
     fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
-        where E: Error
+    where
+        E: Error,
     {
         Ok(v.into_bytes())
     }

test_suite/tests/test_annotations.rs

@@ -12,9 +12,9 @@
 extern crate serde_derive;
 
 extern crate serde;
-use std::collections::HashMap;
-use self::serde::{Deserialize, Deserializer, Serialize, Serializer};
 use self::serde::de::{self, Unexpected};
+use self::serde::{Deserialize, Deserializer, Serialize, Serializer};
+use std::collections::HashMap;
 
 extern crate serde_test;
 use self::serde_test::{assert_de_tokens, assert_de_tokens_error, assert_ser_tokens,
@@ -114,10 +114,7 @@ struct FlattenStructEnumWrapper {
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case")]
 enum FlattenStructEnum {
-    InsertInteger {
+    InsertInteger { index: u32, value: u32 },
-        index: u32,
-        value: u32
-    },
 }
 
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
@@ -133,10 +130,7 @@ struct FlattenStructTagContentEnumNewtype(pub FlattenStructTagContentEnum);
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case", tag = "type", content = "value")]
 enum FlattenStructTagContentEnum {
-    InsertInteger {
+    InsertInteger { index: u32, value: u32 },
-        index: u32,
-        value: u32
-    },
     NewtypeVariant(FlattenStructTagContentEnumNewtypeVariant),
 }
 
@@ -529,12 +523,10 @@ enum RenameEnumSerializeDeserialize<A> {
 fn test_rename_enum() {
     assert_tokens(
         &RenameEnum::Batman,
-        &[
+        &[Token::UnitVariant {
-            Token::UnitVariant {
+            name: "Superhero",
-                name: "Superhero",
+            variant: "bruce_wayne",
-                variant: "bruce_wayne",
+        }],
-            },
-        ],
     );
 
     assert_tokens(
@@ -1221,12 +1213,7 @@ fn test_missing_renamed_field_enum() {
 #[derive(Debug, PartialEq, Deserialize)]
 enum InvalidLengthEnum {
     A(i32, i32, i32),
-    B(
+    B(#[serde(skip_deserializing)] i32, i32, i32),
-        #[serde(skip_deserializing)]
-        i32,
-        i32,
-        i32,
-    ),
 }
 
 #[test]
@@ -1345,7 +1332,7 @@ fn test_flatten_struct_enum() {
     let change_request = FlattenStructEnumWrapper {
         data: FlattenStructEnum::InsertInteger {
             index: 0,
-            value: 42
+            value: 42,
         },
         extra,
     };
@@ -1362,7 +1349,7 @@ fn test_flatten_struct_enum() {
             Token::MapEnd,
             Token::Str("extra_key"),
             Token::Str("extra value"),
-            Token::MapEnd
+            Token::MapEnd,
         ],
     );
     assert_ser_tokens(
@@ -1370,7 +1357,10 @@ fn test_flatten_struct_enum() {
         &[
             Token::Map { len: None },
             Token::Str("insert_integer"),
-            Token::Struct { len: 2, name: "insert_integer" },
+            Token::Struct {
+                len: 2,
+                name: "insert_integer",
+            },
             Token::Str("index"),
             Token::U32(0),
             Token::Str("value"),
@@ -1378,7 +1368,7 @@ fn test_flatten_struct_enum() {
             Token::StructEnd,
             Token::Str("extra_key"),
             Token::Str("extra value"),
-            Token::MapEnd
+            Token::MapEnd,
         ],
     );
 }
@@ -1387,12 +1377,10 @@ fn test_flatten_struct_enum() {
 fn test_flatten_struct_tag_content_enum() {
     let change_request = FlattenStructTagContentEnumWrapper {
         outer: 42,
-        data: FlattenStructTagContentEnumNewtype(
+        data: FlattenStructTagContentEnumNewtype(FlattenStructTagContentEnum::InsertInteger {
-            FlattenStructTagContentEnum::InsertInteger {
+            index: 0,
-                index: 0,
+            value: 42,
-                value: 42
+        }),
-            }
-        ),
     };
     assert_de_tokens(
         &change_request,
@@ -1421,7 +1409,10 @@ fn test_flatten_struct_tag_content_enum() {
             Token::Str("type"),
             Token::Str("insert_integer"),
             Token::Str("value"),
-            Token::Struct { len: 2, name: "insert_integer" },
+            Token::Struct {
+                len: 2,
+                name: "insert_integer",
+            },
             Token::Str("index"),
             Token::U32(0),
             Token::Str("value"),
@@ -1436,13 +1427,9 @@ fn test_flatten_struct_tag_content_enum() {
 fn test_flatten_struct_tag_content_enum_newtype() {
     let change_request = FlattenStructTagContentEnumWrapper {
         outer: 42,
-        data: FlattenStructTagContentEnumNewtype(
+        data: FlattenStructTagContentEnumNewtype(FlattenStructTagContentEnum::NewtypeVariant(
-            FlattenStructTagContentEnum::NewtypeVariant(
+            FlattenStructTagContentEnumNewtypeVariant { value: 23 },
-                FlattenStructTagContentEnumNewtypeVariant {
+        )),
-                    value: 23
-                }
-            )
-        ),
     };
     assert_de_tokens(
         &change_request,
@@ -1469,7 +1456,10 @@ fn test_flatten_struct_tag_content_enum_newtype() {
             Token::Str("type"),
             Token::Str("newtype_variant"),
             Token::Str("value"),
-            Token::Struct { len: 1, name: "FlattenStructTagContentEnumNewtypeVariant" },
+            Token::Struct {
+                len: 1,
+                name: "FlattenStructTagContentEnumNewtypeVariant",
+            },
             Token::Str("value"),
             Token::U32(23),
             Token::StructEnd,
@@ -1525,7 +1515,7 @@ fn test_complex_flatten() {
         first: First,
         #[serde(flatten)]
         second: Second,
-        z: u32
+        z: u32,
     }
 
     #[derive(Debug, PartialEq, Serialize, Deserialize)]
@@ -1552,10 +1542,8 @@ fn test_complex_flatten() {
                 d: "c".into(),
                 e: Some(2),
             },
-            second: Second {
+            second: Second { f: 3 },
-                f: 3
+            z: 4,
-            },
-            z: 4
         },
         &[
             Token::Map { len: None },
@@ -1592,10 +1580,8 @@ fn test_complex_flatten() {
                 d: "c".into(),
                 e: Some(2),
             },
-            second: Second {
+            second: Second { f: 3 },
-                f: 3
+            z: 4,
-            },
-            z: 4
         },
         &[
             Token::Map { len: None },
@@ -1652,7 +1638,7 @@ fn test_flatten_unsupported_type() {
             Token::Str("foo"),
             Token::Str("a"),
             Token::Str("b"),
-            Token::MapEnd
+            Token::MapEnd,
         ],
         "can only flatten structs and maps",
     );
@@ -1671,7 +1657,11 @@ fn test_non_string_keys() {
     let mut mapping = HashMap::new();
     mapping.insert(0, 42);
     assert_tokens(
-        &TestStruct { name: "peter".into(), age: 3, mapping },
+        &TestStruct {
+            name: "peter".into(),
+            age: 3,
+            mapping,
+        },
         &[
             Token::Map { len: None },
             Token::Str("name"),
@@ -1720,7 +1710,9 @@ fn test_lifetime_propagation_for_flatten() {
     let mut borrowed_map = HashMap::new();
     borrowed_map.insert("x", 42u32);
     assert_ser_tokens(
-        &B { t: borrowed_map.clone() },
+        &B {
+            t: borrowed_map.clone(),
+        },
         &[
             Token::Map { len: None },
             Token::BorrowedStr("x"),
@@ -1742,7 +1734,9 @@ fn test_lifetime_propagation_for_flatten() {
     let mut borrowed_map = HashMap::new();
     borrowed_map.insert(&b"x"[..], 42u32);
     assert_ser_tokens(
-        &C { t: borrowed_map.clone() },
+        &C {
+            t: borrowed_map.clone(),
+        },
         &[
             Token::Map { len: None },
             Token::Seq { len: Some(1) },

test_suite/tests/test_de.rs

@@ -12,14 +12,14 @@
 extern crate serde_derive;
 
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
-use std::net;
-use std::path::{Path, PathBuf};
-use std::time::{Duration, UNIX_EPOCH};
 use std::default::Default;
 use std::ffi::{CString, OsString};
+use std::net;
+use std::num::Wrapping;
+use std::path::{Path, PathBuf};
 use std::rc::Rc;
 use std::sync::Arc;
-use std::num::Wrapping;
+use std::time::{Duration, UNIX_EPOCH};
 
 #[cfg(feature = "unstable")]
 use std::ffi::CStr;

test_suite/tests/test_gen.rs

@@ -17,8 +17,8 @@
 extern crate serde_derive;
 
 extern crate serde;
-use self::serde::ser::{Serialize, Serializer};
 use self::serde::de::{DeserializeOwned, Deserializer};
+use self::serde::ser::{Serialize, Serializer};
 
 use std::borrow::Cow;
 use std::marker::PhantomData;
@@ -92,14 +92,10 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     enum EnumWith<T> {
         Unit,
-        Newtype(
+        Newtype(#[serde(serialize_with = "ser_x", deserialize_with = "de_x")] X),
-            #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
-            X,
-        ),
         Tuple(
             T,
-            #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
+            #[serde(serialize_with = "ser_x", deserialize_with = "de_x")] X,
-            X,
         ),
         Struct {
             t: T,
@@ -122,17 +118,13 @@ fn test_gen() {
     assert_ser::<MultipleRef<i32>>();
 
     #[derive(Serialize, Deserialize)]
-    struct Newtype(
+    struct Newtype(#[serde(serialize_with = "ser_x", deserialize_with = "de_x")] X);
-        #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
-        X,
-    );
     assert::<Newtype>();
 
     #[derive(Serialize, Deserialize)]
     struct Tuple<T>(
         T,
-        #[serde(serialize_with = "ser_x", deserialize_with = "de_x")]
+        #[serde(serialize_with = "ser_x", deserialize_with = "de_x")] X,
-        X,
     );
     assert::<Tuple<i32>>();
 
@@ -191,12 +183,16 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     #[serde(bound = "D: SerializeWith + DeserializeWith")]
     struct WithTraits1<D, E> {
-        #[serde(serialize_with = "SerializeWith::serialize_with",
+        #[serde(
-                deserialize_with = "DeserializeWith::deserialize_with")]
+            serialize_with = "SerializeWith::serialize_with",
+            deserialize_with = "DeserializeWith::deserialize_with"
+        )]
         d: D,
-        #[serde(serialize_with = "SerializeWith::serialize_with",
+        #[serde(
-                deserialize_with = "DeserializeWith::deserialize_with",
+            serialize_with = "SerializeWith::serialize_with",
-                bound = "E: SerializeWith + DeserializeWith")]
+            deserialize_with = "DeserializeWith::deserialize_with",
+            bound = "E: SerializeWith + DeserializeWith"
+        )]
         e: E,
     }
     assert::<WithTraits1<X, X>>();
@@ -204,13 +200,18 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     #[serde(bound(serialize = "D: SerializeWith", deserialize = "D: DeserializeWith"))]
     struct WithTraits2<D, E> {
-        #[serde(serialize_with = "SerializeWith::serialize_with",
+        #[serde(
-                deserialize_with = "DeserializeWith::deserialize_with")]
+            serialize_with = "SerializeWith::serialize_with",
+            deserialize_with = "DeserializeWith::deserialize_with"
+        )]
         d: D,
-        #[serde(serialize_with = "SerializeWith::serialize_with",
+        #[serde(
-                bound(serialize = "E: SerializeWith"))]
+            serialize_with = "SerializeWith::serialize_with", bound(serialize = "E: SerializeWith")
-        #[serde(deserialize_with = "DeserializeWith::deserialize_with",
+        )]
-                bound(deserialize = "E: DeserializeWith"))]
+        #[serde(
+            deserialize_with = "DeserializeWith::deserialize_with",
+            bound(deserialize = "E: DeserializeWith")
+        )]
         e: E,
     }
     assert::<WithTraits2<X, X>>();
@@ -270,17 +271,11 @@ fn test_gen() {
     struct EmptyTupleDenyUnknown();
 
     #[derive(Serialize, Deserialize)]
-    struct TupleSkipAll(
+    struct TupleSkipAll(#[serde(skip_deserializing)] u8);
-        #[serde(skip_deserializing)]
-        u8,
-    );
 
     #[derive(Serialize, Deserialize)]
     #[serde(deny_unknown_fields)]
-    struct TupleSkipAllDenyUnknown(
+    struct TupleSkipAllDenyUnknown(#[serde(skip_deserializing)] u8);
-        #[serde(skip_deserializing)]
-        u8,
-    );
 
     #[derive(Serialize, Deserialize)]
     enum EmptyEnum {}
@@ -305,10 +300,7 @@ fn test_gen() {
             #[serde(skip_deserializing)]
             f: u8,
         },
-        TupleSkip(
+        TupleSkip(#[serde(skip_deserializing)] u8),
-            #[serde(skip_deserializing)]
-            u8,
-        ),
     }
 
     #[cfg(feature = "unstable")]
@@ -321,10 +313,7 @@ fn test_gen() {
             #[serde(skip_deserializing)]
             f: u8,
         },
-        TupleSkip(
+        TupleSkip(#[serde(skip_deserializing)] u8),
-            #[serde(skip_deserializing)]
-            u8,
-        ),
     }
 
     #[derive(Serialize, Deserialize)]
@@ -344,9 +333,7 @@ fn test_gen() {
     #[derive(Serialize, Deserialize)]
     #[serde(untagged, remote = "Or")]
     enum OrDef<A, B> {
-        #[allow(dead_code)]
         A(A),
-        #[allow(dead_code)]
         B(B),
     }
 
@@ -503,6 +490,13 @@ fn test_gen() {
     }
     assert_ser::<UntaggedVariantWith>();
 
+    #[derive(Serialize, Deserialize)]
+    struct FlattenWith {
+        #[serde(flatten, serialize_with = "ser_x", deserialize_with = "de_x")]
+        x: X,
+    }
+    assert::<FlattenWith>();
+
     #[derive(Serialize, Deserialize)]
     struct StaticStrStruct<'a> {
         a: &'a str,
@@ -531,7 +525,9 @@ fn test_gen() {
     assert::<SkippedStaticStr>();
 
     macro_rules! T {
-        () => { () }
+        () => {
+            ()
+        };
     }
 
     #[derive(Serialize, Deserialize)]
@@ -559,7 +555,7 @@ fn test_gen() {
 
     #[derive(Serialize, Deserialize)]
     struct AssocDerive<T: AssocSerde> {
-        assoc: T::Assoc
+        assoc: T::Assoc,
     }
 
     assert::<AssocDerive<NoSerdeImpl>>();

test_suite/tests/test_macros.rs

@@ -7,7 +7,6 @@
 // except according to those terms.
 
 #![deny(trivial_numeric_casts)]
-
 #![cfg_attr(feature = "cargo-clippy", allow(redundant_field_names))]
 
 #[macro_use]
@@ -226,12 +225,10 @@ fn test_de_named_map() {
 fn test_ser_enum_unit() {
     assert_ser_tokens(
         &SerEnum::Unit::<u32, u32, u32>,
-        &[
+        &[Token::UnitVariant {
-            Token::UnitVariant {
+            name: "SerEnum",
-                name: "SerEnum",
+            variant: "Unit",
-                variant: "Unit",
+        }],
-            },
-        ],
     );
 }
 
@@ -296,12 +293,10 @@ fn test_ser_enum_map() {
 fn test_de_enum_unit() {
     assert_tokens(
         &DeEnum::Unit::<u32, u32, u32>,
-        &[
+        &[Token::UnitVariant {
-            Token::UnitVariant {
+            name: "DeEnum",
-                name: "DeEnum",
+            variant: "Unit",
-                variant: "Unit",
+        }],
-            },
-        ],
     );
 }
 
@@ -446,6 +441,51 @@ fn test_generic_newtype_struct() {
     );
 }
 
+#[test]
+fn test_untagged_newtype_struct() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(untagged)]
+    enum E {
+        Newtype(GenericNewTypeStruct<u32>),
+        Null,
+    }
+
+    assert_tokens(
+        &E::Newtype(GenericNewTypeStruct(5u32)),
+        &[
+            Token::NewtypeStruct {
+                name: "GenericNewTypeStruct",
+            },
+            Token::U32(5),
+        ],
+    );
+}
+
+#[test]
+fn test_adjacently_tagged_newtype_struct() {
+    #[derive(Debug, PartialEq, Serialize, Deserialize)]
+    #[serde(tag = "t", content = "c")]
+    enum E {
+        Newtype(GenericNewTypeStruct<u32>),
+        Null,
+    }
+
+    assert_de_tokens(
+        &E::Newtype(GenericNewTypeStruct(5u32)),
+        &[
+            Token::Struct { name: "E", len: 2 },
+            Token::Str("c"),
+            Token::NewtypeStruct {
+                name: "GenericNewTypeStruct",
+            },
+            Token::U32(5),
+            Token::Str("t"),
+            Token::Str("Newtype"),
+            Token::StructEnd,
+        ],
+    );
+}
+
 #[test]
 fn test_generic_tuple_struct() {
     assert_tokens(
@@ -466,12 +506,10 @@ fn test_generic_tuple_struct() {
 fn test_generic_enum_unit() {
     assert_tokens(
         &GenericEnum::Unit::<u32, u32>,
-        &[
+        &[Token::UnitVariant {
-            Token::UnitVariant {
+            name: "GenericEnum",
-                name: "GenericEnum",
+            variant: "Unit",
-                variant: "Unit",
+        }],
-            },
-        ],
     );
 }
 
@@ -798,7 +836,9 @@ fn test_internally_tagged_bytes() {
     }
 
     assert_de_tokens(
-        &InternallyTagged::String { string: "\0".to_owned() },
+        &InternallyTagged::String {
+            string: "\0".to_owned(),
+        },
         &[
             Token::Struct {
                 name: "String",
@@ -813,7 +853,9 @@ fn test_internally_tagged_bytes() {
     );
 
     assert_de_tokens(
-        &InternallyTagged::String { string: "\0".to_owned() },
+        &InternallyTagged::String {
+            string: "\0".to_owned(),
+        },
         &[
             Token::Struct {
                 name: "String",
@@ -828,7 +870,9 @@ fn test_internally_tagged_bytes() {
     );
 
     assert_de_tokens(
-        &InternallyTagged::String { string: "\0".to_owned() },
+        &InternallyTagged::String {
+            string: "\0".to_owned(),
+        },
         &[
             Token::Struct {
                 name: "String",
@@ -843,7 +887,9 @@ fn test_internally_tagged_bytes() {
     );
 
     assert_de_tokens(
-        &InternallyTagged::String { string: "\0".to_owned() },
+        &InternallyTagged::String {
+            string: "\0".to_owned(),
+        },
         &[
             Token::Struct {
                 name: "String",
@@ -1354,12 +1400,10 @@ fn test_enum_in_untagged_enum() {
 
     assert_tokens(
         &Outer::Inner(Inner::Unit),
-        &[
+        &[Token::UnitVariant {
-            Token::UnitVariant {
+            name: "Inner",
-                name: "Inner",
+            variant: "Unit",
-                variant: "Unit",
+        }],
-            },
-        ],
     );
 
     assert_tokens(
@@ -1417,7 +1461,9 @@ fn test_untagged_bytes() {
     }
 
     assert_de_tokens(
-        &Untagged::String { string: "\0".to_owned() },
+        &Untagged::String {
+            string: "\0".to_owned(),
+        },
         &[
             Token::Struct {
                 name: "Untagged",
@@ -1430,7 +1476,9 @@ fn test_untagged_bytes() {
     );
 
     assert_de_tokens(
-        &Untagged::String { string: "\0".to_owned() },
+        &Untagged::String {
+            string: "\0".to_owned(),
+        },
         &[
             Token::Struct {
                 name: "Untagged",
@@ -1443,7 +1491,9 @@ fn test_untagged_bytes() {
     );
 
     assert_de_tokens(
-        &Untagged::String { string: "\0".to_owned() },
+        &Untagged::String {
+            string: "\0".to_owned(),
+        },
         &[
             Token::Struct {
                 name: "Untagged",
@@ -1456,7 +1506,9 @@ fn test_untagged_bytes() {
     );
 
     assert_de_tokens(
-        &Untagged::String { string: "\0".to_owned() },
+        &Untagged::String {
+            string: "\0".to_owned(),
+        },
         &[
             Token::Struct {
                 name: "Untagged",

test_suite/tests/test_remote.rs

@@ -121,10 +121,7 @@ struct UnitDef;
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::PrimitivePriv")]
-struct PrimitivePrivDef(
+struct PrimitivePrivDef(#[serde(getter = "remote::PrimitivePriv::get")] u8);
-    #[serde(getter = "remote::PrimitivePriv::get")]
-    u8,
-);
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::PrimitivePub")]
@@ -132,34 +129,22 @@ struct PrimitivePubDef(u8);
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::NewtypePriv")]
-struct NewtypePrivDef(
+struct NewtypePrivDef(#[serde(getter = "remote::NewtypePriv::get", with = "UnitDef")] remote::Unit);
-    #[serde(getter = "remote::NewtypePriv::get", with = "UnitDef")]
-    remote::Unit,
-);
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::NewtypePub")]
-struct NewtypePubDef(
+struct NewtypePubDef(#[serde(with = "UnitDef")] remote::Unit);
-    #[serde(with = "UnitDef")]
-    remote::Unit,
-);
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::TuplePriv")]
 struct TuplePrivDef(
-    #[serde(getter = "remote::TuplePriv::first")]
+    #[serde(getter = "remote::TuplePriv::first")] u8,
-    u8,
+    #[serde(getter = "remote::TuplePriv::second", with = "UnitDef")] remote::Unit,
-    #[serde(getter = "remote::TuplePriv::second", with = "UnitDef")]
-    remote::Unit,
 );
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::TuplePub")]
-struct TuplePubDef(
+struct TuplePubDef(u8, #[serde(with = "UnitDef")] remote::Unit);
-    u8,
-    #[serde(with = "UnitDef")]
-    remote::Unit,
-);
 
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::StructPriv")]
@@ -175,10 +160,8 @@ struct StructPrivDef {
 #[derive(Serialize, Deserialize)]
 #[serde(remote = "remote::StructPub")]
 struct StructPubDef {
-    #[allow(dead_code)]
     a: u8,
 
-    #[allow(dead_code)]
     #[serde(with = "UnitDef")]
     b: remote::Unit,
 }

test_suite/tests/test_ser.rs

@@ -10,13 +10,13 @@
 extern crate serde_derive;
 
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
-use std::net;
-use std::path::{Path, PathBuf};
-use std::time::{Duration, UNIX_EPOCH};
 use std::ffi::CString;
+use std::net;
+use std::num::Wrapping;
+use std::path::{Path, PathBuf};
 use std::rc::Rc;
 use std::sync::Arc;
-use std::num::Wrapping;
+use std::time::{Duration, UNIX_EPOCH};
 
 #[cfg(unix)]
 use std::str;

test_suite/tests/test_value.rs

@@ -10,8 +10,8 @@
 extern crate serde_derive;
 
 extern crate serde;
-use serde::Deserialize;
 use serde::de::{value, IntoDeserializer};
+use serde::Deserialize;
 
 #[test]
 fn test_u32_to_enum() {

travis.sh

@@ -87,4 +87,10 @@ else
     channel build --no-default-features
     cd "$DIR/serde_test"
     channel build
+
+    CHANNEL=1.15.0
+    cd "$DIR"
+    cargo clean
+    cd "$DIR/serde_derive"
+    channel build
 fi