Use optimized output for Clone and PartialOrd with custom bounds (#…

…95)

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Changed
+- Use the `Copy` implementation for `Clone` and the `Ord` implementation for
+ `PartialOrd` when custom bounds are present.
+
 ## [1.2.7] - 2023-12-14
 
 ### Fixed

src/lib.rs

@@ -636,7 +636,7 @@ fn generate_impl(
  let mut where_clause = where_clause.map(Cow::Borrowed);
  derive_where.where_clause(&mut where_clause, trait_, item);
 
- let body = generate_body(derive_where, &derive_where.traits, trait_, item, generics);
+ let body = generate_body(derive_where, trait_, item, generics);
 
  let ident = item.ident();
  let path = trait_.impl_path(trait_);
@@ -666,25 +666,22 @@ fn generate_impl(
 /// Generate implementation method body for a [`Trait`].
 fn generate_body(
  derive_where: &DeriveWhere,
- traits: &[DeriveTrait],
  trait_: &DeriveTrait,
  item: &Item,
  generics: &SplitGenerics<'_>,
 ) -> TokenStream {
- let any_bound = !derive_where.generics.is_empty();
-
  match &item {
  Item::Item(data) => {
- let body = trait_.build_body(any_bound, traits, trait_, data);
- trait_.build_signature(any_bound, item, generics, traits, trait_, &body)
+ let body = trait_.build_body(derive_where, trait_, data);
+ trait_.build_signature(derive_where, item, generics, trait_, &body)
  }
  Item::Enum { variants, .. } => {
  let body: TokenStream = variants
  .iter()
- .map(|data| trait_.build_body(any_bound, traits, trait_, data))
+ .map(|data| trait_.build_body(derive_where, trait_, data))
  .collect();
 
- trait_.build_signature(any_bound, item, generics, traits, trait_, &body)
+ trait_.build_signature(derive_where, item, generics, trait_, &body)
  }
  }
 }

src/test/bound.rs

@@ -7,7 +7,7 @@ use super::test_derive;
 fn bound() -> Result<()> {
  test_derive(
  quote! {
- #[derive_where(Clone; T)]
+ #[derive_where(Clone, Copy; T)]
  struct Test<T, U>(T, std::marker::PhantomData<U>);
  },
  quote! {
@@ -22,6 +22,11 @@ fn bound() -> Result<()> {
  }
  }
  }
+
+ #[automatically_derived]
+ impl<T, U> ::core::marker::Copy for Test<T, U>
+ where T: ::core::marker::Copy
+ { }
  },
  )
 }
@@ -30,7 +35,7 @@ fn bound() -> Result<()> {
 fn bound_multiple() -> Result<()> {
  test_derive(
  quote! {
- #[derive_where(Clone; T, U)]
+ #[derive_where(Clone, Copy; T, U)]
  struct Test<T, U, V>((T, U), std::marker::PhantomData<V>);
  },
  quote! {
@@ -47,6 +52,13 @@ fn bound_multiple() -> Result<()> {
  }
  }
  }
+
+ #[automatically_derived]
+ impl<T, U, V> ::core::marker::Copy for Test<T, U, V>
+ where
+ T: ::core::marker::Copy,
+ U: ::core::marker::Copy
+ { }
  },
  )
 }

src/test/clone.rs

@@ -95,8 +95,59 @@ fn union_() -> Result<()> {
  fn clone(&self) -> Self {
  struct __AssertCopy<__T: ::core::marker::Copy + ?::core::marker::Sized>(::core::marker::PhantomData<__T>);
  let _: __AssertCopy<Self>;
+ *self
  }
  }
  },
  )
 }
+
+#[test]
+fn no_bound() -> Result<()> {
+ test_derive(
+ quote! {
+ #[derive_where(Clone, Copy)]
+ struct Test<T>(std::marker::PhantomData<T>);
+ },
+ quote! {
+ #[automatically_derived]
+ impl<T> ::core::clone::Clone for Test<T>
+ {
+ #[inline]
+ fn clone(&self) -> Self {
+ *self
+ }
+ }
+
+ #[automatically_derived]
+ impl<T> ::core::marker::Copy for Test<T>
+ { }
+ },
+ )
+}
+
+#[test]
+fn custom_bound() -> Result<()> {
+ test_derive(
+ quote! {
+ #[derive_where(Clone, Copy; T: Trait)]
+ struct Test<T>(T);
+ },
+ quote! {
+ #[automatically_derived]
+ impl<T> ::core::clone::Clone for Test<T>
+ where T: Trait
+ {
+ #[inline]
+ fn clone(&self) -> Self {
+ *self
+ }
+ }
+
+ #[automatically_derived]
+ impl<T> ::core::marker::Copy for Test<T>
+ where T: Trait
+ { }
+ },
+ )
+}

src/test/mod.rs

@@ -1,5 +1,6 @@
 mod basic;
 mod bound;
+mod clone;
 mod discriminant;
 mod enum_;
 #[cfg(not(any(feature = "nightly", feature = "safe")))]

src/test/partial_ord.rs

@@ -200,3 +200,73 @@ fn bound() -> Result<()> {
  },
  )
 }
+
+#[test]
+fn no_bound() -> Result<()> {
+ test_derive(
+ quote! {
+ #[derive_where(Ord, PartialOrd)]
+ struct Test<T>(std::marker::PhantomData<T>);
+ },
+ quote! {
+ #[automatically_derived]
+ impl<T> ::core::cmp::Ord for Test<T> {
+ #[inline]
+ fn cmp(&self, __other: &Self) -> ::core::cmp::Ordering {
+ match (self, __other) {
+ (Test(ref __field_0), Test(ref __other_field_0)) =>
+ match ::core::cmp::Ord::cmp(__field_0, __other_field_0) {
+ ::core::cmp::Ordering::Equal => ::core::cmp::Ordering::Equal,
+ __cmp => __cmp,
+ },
+ }
+ }
+ }
+
+ #[automatically_derived]
+ impl<T> ::core::cmp::PartialOrd for Test<T> {
+ #[inline]
+ fn partial_cmp(&self, __other: &Self) -> ::core::option::Option<::core::cmp::Ordering> {
+ ::core::option::Option::Some(::core::cmp::Ord::cmp(self, __other))
+ }
+ }
+ },
+ )
+}
+
+#[test]
+fn custom_bound() -> Result<()> {
+ test_derive(
+ quote! {
+ #[derive_where(Ord, PartialOrd; T: TestTrait)]
+ struct Test<T>(std::marker::PhantomData<T>);
+ },
+ quote! {
+ #[automatically_derived]
+ impl<T> ::core::cmp::Ord for Test<T>
+ where T: TestTrait
+ {
+ #[inline]
+ fn cmp(&self, __other: &Self) -> ::core::cmp::Ordering {
+ match (self, __other) {
+ (Test(ref __field_0), Test(ref __other_field_0)) =>
+ match ::core::cmp::Ord::cmp(__field_0, __other_field_0) {
+ ::core::cmp::Ordering::Equal => ::core::cmp::Ordering::Equal,
+ __cmp => __cmp,
+ },
+ }
+ }
+ }
+
+ #[automatically_derived]
+ impl<T> ::core::cmp::PartialOrd for Test<T>
+ where T: TestTrait
+ {
+ #[inline]
+ fn partial_cmp(&self, __other: &Self) -> ::core::option::Option<::core::cmp::Ordering> {
+ ::core::option::Option::Some(::core::cmp::Ord::cmp(self, __other))
+ }
+ }
+ },
+ )
+}

src/trait_.rs

@@ -18,7 +18,7 @@ mod zeroize_on_drop;
 use proc_macro2::{Span, TokenStream};
 use syn::{punctuated::Punctuated, spanned::Spanned, Meta, Path, Result, Token, TypeParamBound};
 
-use crate::{Data, DeriveTrait, Error, Item, SplitGenerics};
+use crate::{Data, DeriveTrait, DeriveWhere, Error, Item, SplitGenerics};
 
 /// Type implementing [`TraitImpl`] for every trait.
 #[derive(Clone, Copy, Eq, PartialEq)]
@@ -133,26 +133,23 @@ impl TraitImpl for Trait {
 
  fn build_signature(
  &self,
- any_bound: bool,
+ derive_where: &DeriveWhere,
  item: &Item,
  generics: &SplitGenerics<'_>,
- traits: &[DeriveTrait],
  trait_: &DeriveTrait,
  body: &TokenStream,
  ) -> TokenStream {
  self.implementation()
- .build_signature(any_bound, item, generics, traits, trait_, body)
+ .build_signature(derive_where, item, generics, trait_, body)
  }
 
  fn build_body(
  &self,
- any_bound: bool,
- traits: &[DeriveTrait],
+ derive_where: &DeriveWhere,
  trait_: &DeriveTrait,
  data: &Data,
  ) -> TokenStream {
- self.implementation()
- .build_body(any_bound, traits, trait_, data)
+ self.implementation().build_body(derive_where, trait_, data)
  }
 }
 
@@ -199,10 +196,9 @@ pub trait TraitImpl {
  /// Build method signature for this [`Trait`].
  fn build_signature(
  &self,
- _any_bound: bool,
+ _derive_where: &DeriveWhere,
  _item: &Item,
  _generics: &SplitGenerics<'_>,
- _traits: &[DeriveTrait],
  _trait_: &DeriveTrait,
  _body: &TokenStream,
  ) -> TokenStream {
@@ -212,8 +208,7 @@ pub trait TraitImpl {
  /// Build method body for this [`Trait`].
  fn build_body(
  &self,
- _any_bound: bool,
- _traits: &[DeriveTrait],
+ _derive_where: &DeriveWhere,
  _trait_: &DeriveTrait,
  _data: &Data,
  ) -> TokenStream {

src/trait_/clone.rs

@@ -4,7 +4,9 @@ use proc_macro2::TokenStream;
 use quote::quote;
 use syn::{TraitBound, TraitBoundModifier, TypeParamBound};
 
-use crate::{Data, DataType, DeriveTrait, Item, SimpleType, SplitGenerics, Trait, TraitImpl};
+use crate::{
+ Data, DataType, DeriveTrait, DeriveWhere, Item, SimpleType, SplitGenerics, Trait, TraitImpl,
+};
 
 /// Dummy-struct implement [`Trait`] for [`Clone`](trait@std::clone::Clone).
 pub struct Clone;
@@ -42,15 +44,16 @@ impl TraitImpl for Clone {
 
  fn build_signature(
  &self,
- any_bound: bool,
+ derive_where: &DeriveWhere,
  item: &Item,
  _generics: &SplitGenerics<'_>,
- traits: &[DeriveTrait],
  _trait_: &DeriveTrait,
  body: &TokenStream,
  ) -> TokenStream {
  // Special implementation for items also implementing `Copy`.
- if !any_bound && traits.iter().any(|trait_| trait_ == Trait::Copy) {
+ if (derive_where.generics.is_empty() || derive_where.any_custom_bound())
+ && derive_where.contains(Trait::Copy)
+ {
  return quote! {
  #[inline]
  fn clone(&self) -> Self { *self }
@@ -85,12 +88,13 @@ impl TraitImpl for Clone {
 
  fn build_body(
  &self,
- any_bound: bool,
- traits: &[DeriveTrait],
+ derive_where: &DeriveWhere,
  trait_: &DeriveTrait,
  data: &Data,
  ) -> TokenStream {
- if !any_bound && traits.iter().any(|trait_| trait_ == Trait::Copy) {
+ if (derive_where.generics.is_empty() || derive_where.any_custom_bound())
+ && derive_where.contains(Trait::Copy)
+ {
  return TokenStream::new();
  }
 

src/trait_/common_ord.rs

@@ -14,13 +14,13 @@ use syn::{parse_quote, Expr, ExprLit, LitInt, Path};
 
 #[cfg(not(feature = "nightly"))]
 use crate::{item::Representation, Discriminant, Trait};
-use crate::{Data, DeriveTrait, Item, SimpleType, SplitGenerics};
+use crate::{Data, DeriveTrait, DeriveWhere, Item, SimpleType, SplitGenerics};
 
 /// Build signature for [`PartialOrd`] and [`Ord`].
 pub fn build_ord_signature(
  item: &Item,
  #[cfg_attr(feature = "nightly", allow(unused_variables))] generics: &SplitGenerics<'_>,
- #[cfg_attr(feature = "nightly", allow(unused_variables))] traits: &[DeriveTrait],
+ #[cfg_attr(feature = "nightly", allow(unused_variables))] derive_where: &DeriveWhere,
  trait_: &DeriveTrait,
  body: &TokenStream,
 ) -> TokenStream {
@@ -173,13 +173,13 @@ pub fn build_ord_signature(
  }
  });
 
- if traits.iter().any(|trait_| trait_ == Trait::Copy) {
+ if derive_where.contains(Trait::Copy) {
  quote! {
  #validate
 
  #path::#method(&(*self as isize), &(*__other as isize))
  }
- } else if traits.iter().any(|trait_| trait_ == Trait::Clone) {
+ } else if derive_where.contains(Trait::Clone) {
  let clone = DeriveTrait::Clone.path();
  quote! {
  #validate
@@ -215,11 +215,11 @@ pub fn build_ord_signature(
  )
  }
  Discriminant::UnitRepr(repr) => {
- if traits.iter().any(|trait_| trait_ == Trait::Copy) {
+ if derive_where.contains(Trait::Copy) {
  quote! {
  #path::#method(&(*self as #repr), &(*__other as #repr))
  }
- } else if traits.iter().any(|trait_| trait_ == Trait::Clone) {
+ } else if derive_where.contains(Trait::Clone) {
  let clone = DeriveTrait::Clone.path();
  quote! {
  #path::#method(&(#clone::clone(self) as #repr), &(#clone::clone(__other) as #repr))