From b363d84e4e0e166a06d99b25cd1218068d642bf7 Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Fri, 11 Jul 2025 10:21:29 +0000 Subject: [PATCH 1/4] Make `Option` `const PartialEq` --- library/core/src/option.rs | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/library/core/src/option.rs b/library/core/src/option.rs index 4ede273feda9b..52f6d89ff254d 100644 --- a/library/core/src/option.rs +++ b/library/core/src/option.rs @@ -2243,7 +2243,8 @@ impl<'a, T> From<&'a mut Option> for Option<&'a mut T> { #[stable(feature = "rust1", since = "1.0.0")] impl crate::marker::StructuralPartialEq for Option {} #[stable(feature = "rust1", since = "1.0.0")] -impl PartialEq for Option { +#[rustc_const_unstable(feature = "const_cmp", issue = "143800")] +impl const PartialEq for Option { #[inline] fn eq(&self, other: &Self) -> bool { // Spelling out the cases explicitly optimizes better than From 5d9c537aa48a083c40556c42325570ed8ec82ca8 Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Fri, 11 Jul 2025 10:34:29 +0000 Subject: [PATCH 2/4] Make `NonZero` `const PartialEq` --- library/core/src/num/nonzero.rs | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs index 11d50e0f89f30..b8900c4113ad3 100644 --- a/library/core/src/num/nonzero.rs +++ b/library/core/src/num/nonzero.rs @@ -200,9 +200,10 @@ impl UseCloned for NonZero where T: ZeroablePrimitive {} impl Copy for NonZero where T: ZeroablePrimitive {} #[stable(feature = "nonzero", since = "1.28.0")] -impl PartialEq for NonZero +#[rustc_const_unstable(feature = "const_cmp", issue = "143800")] +impl const PartialEq for NonZero where - T: ZeroablePrimitive + PartialEq, + T: ZeroablePrimitive + ~const PartialEq, { #[inline] fn eq(&self, other: &Self) -> bool { From 5d5b36d49cf9eee518c93e1db4e675702a25280a Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Fri, 11 Jul 2025 10:20:25 +0000 Subject: [PATCH 3/4] Make `derive_const` usable within libcore again Also make it *only* usable on nightly --- .../src/deriving/bounds.rs | 4 ++ .../src/deriving/clone.rs | 1 + .../src/deriving/cmp/eq.rs | 1 + .../src/deriving/cmp/ord.rs | 1 + .../src/deriving/cmp/partial_eq.rs | 2 + .../src/deriving/cmp/partial_ord.rs | 1 + .../src/deriving/debug.rs | 1 + .../src/deriving/default.rs | 1 + .../src/deriving/generic/mod.rs | 47 +++++++++++++++++-- .../rustc_builtin_macros/src/deriving/hash.rs | 1 + compiler/rustc_expand/src/build.rs | 10 +++- compiler/rustc_span/src/symbol.rs | 1 + library/core/src/macros/mod.rs | 2 +- library/core/src/prelude/v1.rs | 2 +- library/std/src/prelude/v1.rs | 2 +- .../consts/const-eval/auxiliary/stability.rs | 9 ++-- .../const_derives/derive-const-gate.stderr | 1 + 17 files changed, 75 insertions(+), 12 deletions(-) diff --git a/compiler/rustc_builtin_macros/src/deriving/bounds.rs b/compiler/rustc_builtin_macros/src/deriving/bounds.rs index a98e9c6d1c7fc..dd8f0e46a0e03 100644 --- a/compiler/rustc_builtin_macros/src/deriving/bounds.rs +++ b/compiler/rustc_builtin_macros/src/deriving/bounds.rs @@ -23,6 +23,7 @@ pub(crate) fn expand_deriving_copy( methods: Vec::new(), associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push); @@ -46,6 +47,7 @@ pub(crate) fn expand_deriving_const_param_ty( methods: Vec::new(), associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push); @@ -60,6 +62,7 @@ pub(crate) fn expand_deriving_const_param_ty( methods: Vec::new(), associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push); @@ -83,6 +86,7 @@ pub(crate) fn expand_deriving_unsized_const_param_ty( methods: Vec::new(), associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push); diff --git a/compiler/rustc_builtin_macros/src/deriving/clone.rs b/compiler/rustc_builtin_macros/src/deriving/clone.rs index 69f8c273797e4..3c78f53c5cb0a 100644 --- a/compiler/rustc_builtin_macros/src/deriving/clone.rs +++ b/compiler/rustc_builtin_macros/src/deriving/clone.rs @@ -87,6 +87,7 @@ pub(crate) fn expand_deriving_clone( }], associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand_ext(cx, mitem, item, push, is_simple) diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs index eca79e4dc4897..29d531219a69c 100644 --- a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs +++ b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs @@ -43,6 +43,7 @@ pub(crate) fn expand_deriving_eq( }], associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand_ext(cx, mitem, item, push, true) } diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs index 1ed44c20bc61e..0e1ecf3118ac3 100644 --- a/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs +++ b/compiler/rustc_builtin_macros/src/deriving/cmp/ord.rs @@ -34,6 +34,7 @@ pub(crate) fn expand_deriving_ord( }], associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push) diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs index b1d950b8d89de..990835fa27739 100644 --- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs +++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_eq.rs @@ -30,6 +30,7 @@ pub(crate) fn expand_deriving_partial_eq( methods: Vec::new(), associated_types: Vec::new(), is_const: false, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; structural_trait_def.expand(cx, mitem, item, push); @@ -58,6 +59,7 @@ pub(crate) fn expand_deriving_partial_eq( methods, associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push) } diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs index 0a076dd670b34..f5d262ece36e3 100644 --- a/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs +++ b/compiler/rustc_builtin_macros/src/deriving/cmp/partial_ord.rs @@ -64,6 +64,7 @@ pub(crate) fn expand_deriving_partial_ord( methods: vec![partial_cmp_def], associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push) } diff --git a/compiler/rustc_builtin_macros/src/deriving/debug.rs b/compiler/rustc_builtin_macros/src/deriving/debug.rs index 8ab21986e68a0..1d63ce7d5fd27 100644 --- a/compiler/rustc_builtin_macros/src/deriving/debug.rs +++ b/compiler/rustc_builtin_macros/src/deriving/debug.rs @@ -41,6 +41,7 @@ pub(crate) fn expand_deriving_debug( }], associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push) } diff --git a/compiler/rustc_builtin_macros/src/deriving/default.rs b/compiler/rustc_builtin_macros/src/deriving/default.rs index 1fe567e23f455..b4e2d27fed333 100644 --- a/compiler/rustc_builtin_macros/src/deriving/default.rs +++ b/compiler/rustc_builtin_macros/src/deriving/default.rs @@ -51,6 +51,7 @@ pub(crate) fn expand_deriving_default( }], associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; trait_def.expand(cx, mitem, item, push) } diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs index 8c3093acea450..a0bb04ed9b8cd 100644 --- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs +++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs @@ -181,9 +181,11 @@ use std::{iter, vec}; pub(crate) use StaticFields::*; pub(crate) use SubstructureFields::*; use rustc_ast::ptr::P; +use rustc_ast::token::{IdentIsRaw, LitKind, Token, TokenKind}; +use rustc_ast::tokenstream::{DelimSpan, Spacing, TokenTree}; use rustc_ast::{ - self as ast, AnonConst, BindingMode, ByRef, EnumDef, Expr, GenericArg, GenericParamKind, - Generics, Mutability, PatKind, VariantData, + self as ast, AnonConst, AttrArgs, BindingMode, ByRef, DelimArgs, EnumDef, Expr, GenericArg, + GenericParamKind, Generics, Mutability, PatKind, Safety, VariantData, }; use rustc_attr_data_structures::{AttributeKind, ReprPacked}; use rustc_attr_parsing::AttributeParser; @@ -222,6 +224,8 @@ pub(crate) struct TraitDef<'a> { pub associated_types: Vec<(Ident, Ty)>, pub is_const: bool, + + pub is_staged_api_crate: bool, } pub(crate) struct MethodDef<'a> { @@ -784,8 +788,45 @@ impl<'a> TraitDef<'a> { // Create the type of `self`. let path = cx.path_all(self.span, false, vec![type_ident], self_params); let self_type = cx.ty_path(path); + let rustc_const_unstable = + cx.path_ident(self.span, Ident::new(sym::rustc_const_unstable, self.span)); + + let mut attrs = thin_vec![cx.attr_word(sym::automatically_derived, self.span),]; + + // Only add `rustc_const_unstable` attributes if `derive_const` is used within libcore/libstd, + // Other crates don't need stability attributes, so adding them is not useful, but libcore needs them + // on all const trait impls. + if self.is_const && self.is_staged_api_crate { + attrs.push( + cx.attr_nested( + rustc_ast::AttrItem { + unsafety: Safety::Default, + path: rustc_const_unstable, + args: AttrArgs::Delimited(DelimArgs { + dspan: DelimSpan::from_single(self.span), + delim: rustc_ast::token::Delimiter::Parenthesis, + tokens: [ + TokenKind::Ident(sym::feature, IdentIsRaw::No), + TokenKind::Eq, + TokenKind::lit(LitKind::Str, sym::derive_const, None), + TokenKind::Comma, + TokenKind::Ident(sym::issue, IdentIsRaw::No), + TokenKind::Eq, + TokenKind::lit(LitKind::Str, sym::derive_const_issue, None), + ] + .into_iter() + .map(|kind| { + TokenTree::Token(Token { kind, span: self.span }, Spacing::Alone) + }) + .collect(), + }), + tokens: None, + }, + self.span, + ), + ) + } - let attrs = thin_vec![cx.attr_word(sym::automatically_derived, self.span),]; let opt_trait_ref = Some(trait_ref); cx.item( diff --git a/compiler/rustc_builtin_macros/src/deriving/hash.rs b/compiler/rustc_builtin_macros/src/deriving/hash.rs index 6e6dbe19e4d1a..78534449895c2 100644 --- a/compiler/rustc_builtin_macros/src/deriving/hash.rs +++ b/compiler/rustc_builtin_macros/src/deriving/hash.rs @@ -41,6 +41,7 @@ pub(crate) fn expand_deriving_hash( }], associated_types: Vec::new(), is_const, + is_staged_api_crate: cx.ecfg.features.staged_api(), }; hash_trait_def.expand(cx, mitem, item, push); diff --git a/compiler/rustc_expand/src/build.rs b/compiler/rustc_expand/src/build.rs index 85683c1a03ff2..51d6e43ab6720 100644 --- a/compiler/rustc_expand/src/build.rs +++ b/compiler/rustc_expand/src/build.rs @@ -3,8 +3,8 @@ use rustc_ast::token::Delimiter; use rustc_ast::tokenstream::TokenStream; use rustc_ast::util::literal; use rustc_ast::{ - self as ast, AnonConst, AttrVec, BlockCheckMode, Expr, LocalKind, MatchKind, PatKind, UnOp, - attr, token, tokenstream, + self as ast, AnonConst, AttrItem, AttrVec, BlockCheckMode, Expr, LocalKind, MatchKind, PatKind, + UnOp, attr, token, tokenstream, }; use rustc_span::source_map::Spanned; use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw, sym}; @@ -766,4 +766,10 @@ impl<'a> ExtCtxt<'a> { span, ) } + + // Builds an attribute fully manually. + pub fn attr_nested(&self, inner: AttrItem, span: Span) -> ast::Attribute { + let g = &self.sess.psess.attr_id_generator; + attr::mk_attr_from_item(g, inner, None, ast::AttrStyle::Outer, span) + } } diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 8b12edf426c1b..96094953558b4 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -839,6 +839,7 @@ symbols! { derive, derive_coerce_pointee, derive_const, + derive_const_issue: "118304", derive_default_enum, derive_smart_pointer, destruct, diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs index 6b9cbb0643586..76e75d94a367f 100644 --- a/library/core/src/macros/mod.rs +++ b/library/core/src/macros/mod.rs @@ -1617,7 +1617,7 @@ pub(crate) mod builtin { /// See [the reference] for more info. /// /// [the reference]: ../../../reference/attributes/derive.html - #[unstable(feature = "derive_const", issue = "none")] + #[unstable(feature = "derive_const", issue = "118304")] #[rustc_builtin_macro] pub macro derive_const($item:item) { /* compiler built-in */ diff --git a/library/core/src/prelude/v1.rs b/library/core/src/prelude/v1.rs index 7b9e04920d51d..a4be66b90cab3 100644 --- a/library/core/src/prelude/v1.rs +++ b/library/core/src/prelude/v1.rs @@ -80,7 +80,7 @@ pub use crate::macros::builtin::{ alloc_error_handler, bench, derive, global_allocator, test, test_case, }; -#[unstable(feature = "derive_const", issue = "none")] +#[unstable(feature = "derive_const", issue = "118304")] pub use crate::macros::builtin::derive_const; #[unstable( diff --git a/library/std/src/prelude/v1.rs b/library/std/src/prelude/v1.rs index 69f0335315356..70c1113155656 100644 --- a/library/std/src/prelude/v1.rs +++ b/library/std/src/prelude/v1.rs @@ -67,7 +67,7 @@ pub use core::prelude::v1::{ alloc_error_handler, bench, derive, global_allocator, test, test_case, }; -#[unstable(feature = "derive_const", issue = "none")] +#[unstable(feature = "derive_const", issue = "118304")] pub use core::prelude::v1::derive_const; // Do not `doc(no_inline)` either. diff --git a/tests/ui/consts/const-eval/auxiliary/stability.rs b/tests/ui/consts/const-eval/auxiliary/stability.rs index e615955186020..48ced3bc51e62 100644 --- a/tests/ui/consts/const-eval/auxiliary/stability.rs +++ b/tests/ui/consts/const-eval/auxiliary/stability.rs @@ -1,10 +1,11 @@ // Crate that exports a const fn. Used for testing cross-crate. -#![crate_type="rlib"] +#![crate_type = "rlib"] #![stable(feature = "rust1", since = "1.0.0")] - #![feature(staged_api)] #[stable(feature = "rust1", since = "1.0.0")] -#[rustc_const_unstable(feature="foo", issue = "none")] -pub const fn foo() -> u32 { 42 } +#[rustc_const_unstable(feature = "foo", issue = "none")] +pub const fn foo() -> u32 { + 42 +} diff --git a/tests/ui/traits/const-traits/const_derives/derive-const-gate.stderr b/tests/ui/traits/const-traits/const_derives/derive-const-gate.stderr index 5bde358001cbc..f5d90544411b2 100644 --- a/tests/ui/traits/const-traits/const_derives/derive-const-gate.stderr +++ b/tests/ui/traits/const-traits/const_derives/derive-const-gate.stderr @@ -4,6 +4,7 @@ error[E0658]: use of unstable library feature `derive_const` LL | #[derive_const(Debug)] | ^^^^^^^^^^^^ | + = note: see issue #118304 for more information = help: add `#![feature(derive_const)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date From 19c2f1b7c539de7f54333c1a1fb2a779f8a29013 Mon Sep 17 00:00:00 2001 From: Oli Scherer Date: Fri, 11 Jul 2025 10:20:25 +0000 Subject: [PATCH 4/4] Make slices `[const] PartialEq` --- library/core/src/cmp.rs | 3 ++- library/core/src/cmp/bytewise.rs | 8 +++++-- library/core/src/intrinsics/mod.rs | 1 + library/core/src/lib.rs | 2 ++ library/core/src/slice/cmp.rs | 22 +++++++++++++------ library/core/src/str/traits.rs | 3 ++- tests/ui/consts/const-compare-bytes-ub.rs | 2 +- tests/ui/consts/const-compare-bytes.rs | 2 +- .../traits/const-traits/const-impl-trait.rs | 2 +- .../match-non-const-eq.gated.stderr | 12 ---------- .../traits/const-traits/match-non-const-eq.rs | 9 ++++---- .../match-non-const-eq.stock.stderr | 22 +++++++++++++++---- 12 files changed, 54 insertions(+), 34 deletions(-) delete mode 100644 tests/ui/traits/const-traits/match-non-const-eq.gated.stderr diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs index 03b120fbf0c34..6419ae9911359 100644 --- a/library/core/src/cmp.rs +++ b/library/core/src/cmp.rs @@ -381,7 +381,8 @@ pub struct AssertParamIsEq { /// /// assert_eq!(2.cmp(&1), Ordering::Greater); /// ``` -#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)] +#[derive(Clone, Copy, Eq, PartialOrd, Ord, Debug, Hash)] +#[derive_const(PartialEq)] #[stable(feature = "rust1", since = "1.0.0")] // This is a lang item only so that `BinOp::Cmp` in MIR can return it. // It has no special behavior, but does require that the three variants diff --git a/library/core/src/cmp/bytewise.rs b/library/core/src/cmp/bytewise.rs index a06a5227fe285..7d61c9345ecf8 100644 --- a/library/core/src/cmp/bytewise.rs +++ b/library/core/src/cmp/bytewise.rs @@ -17,11 +17,15 @@ use crate::num::NonZero; /// - Neither `Self` nor `Rhs` have provenance, so integer comparisons are correct. /// - `>::{eq,ne}` are equivalent to comparing the bytes. #[rustc_specialization_trait] -pub(crate) unsafe trait BytewiseEq: PartialEq + Sized {} +#[const_trait] +pub(crate) unsafe trait BytewiseEq: + ~const PartialEq + Sized +{ +} macro_rules! is_bytewise_comparable { ($($t:ty),+ $(,)?) => {$( - unsafe impl BytewiseEq for $t {} + unsafe impl const BytewiseEq for $t {} )+}; } diff --git a/library/core/src/intrinsics/mod.rs b/library/core/src/intrinsics/mod.rs index c2e4b751c65f3..36535848263df 100644 --- a/library/core/src/intrinsics/mod.rs +++ b/library/core/src/intrinsics/mod.rs @@ -2208,6 +2208,7 @@ pub const unsafe fn raw_eq(a: &T, b: &T) -> bool; /// [valid]: crate::ptr#safety #[rustc_nounwind] #[rustc_intrinsic] +#[rustc_const_unstable(feature = "const_cmp", issue = "143800")] pub const unsafe fn compare_bytes(left: *const u8, right: *const u8, bytes: usize) -> i32; /// See documentation of [`std::hint::black_box`] for details. diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs index 2f701171505c7..fedc4dada2037 100644 --- a/library/core/src/lib.rs +++ b/library/core/src/lib.rs @@ -103,6 +103,7 @@ #![feature(cfg_select)] #![feature(cfg_target_has_reliable_f16_f128)] #![feature(const_carrying_mul_add)] +#![feature(const_cmp)] #![feature(const_destruct)] #![feature(const_eval_select)] #![feature(core_intrinsics)] @@ -146,6 +147,7 @@ #![feature(const_trait_impl)] #![feature(decl_macro)] #![feature(deprecated_suggestion)] +#![feature(derive_const)] #![feature(doc_cfg)] #![feature(doc_cfg_hide)] #![feature(doc_notable_trait)] diff --git a/library/core/src/slice/cmp.rs b/library/core/src/slice/cmp.rs index 5ce72b46eee36..1eda8bc1bec40 100644 --- a/library/core/src/slice/cmp.rs +++ b/library/core/src/slice/cmp.rs @@ -8,9 +8,10 @@ use crate::num::NonZero; use crate::ops::ControlFlow; #[stable(feature = "rust1", since = "1.0.0")] -impl PartialEq<[U]> for [T] +#[rustc_const_unstable(feature = "const_cmp", issue = "143800")] +impl const PartialEq<[U]> for [T] where - T: PartialEq, + T: ~const PartialEq, { fn eq(&self, other: &[U]) -> bool { SlicePartialEq::equal(self, other) @@ -94,6 +95,8 @@ impl PartialOrd for [T] { #[doc(hidden)] // intermediate trait for specialization of slice's PartialEq +#[const_trait] +#[rustc_const_unstable(feature = "const_cmp", issue = "143800")] trait SlicePartialEq { fn equal(&self, other: &[B]) -> bool; @@ -103,9 +106,10 @@ trait SlicePartialEq { } // Generic slice equality -impl SlicePartialEq for [A] +#[rustc_const_unstable(feature = "const_cmp", issue = "143800")] +impl const SlicePartialEq for [A] where - A: PartialEq, + A: ~const PartialEq, { default fn equal(&self, other: &[B]) -> bool { if self.len() != other.len() { @@ -115,11 +119,14 @@ where // Implemented as explicit indexing rather // than zipped iterators for performance reasons. // See PR https://github.com/rust-lang/rust/pull/116846 - for idx in 0..self.len() { + // FIXME(const_hack): make this a `for idx in 0..self.len()` loop. + let mut idx = 0; + while idx < self.len() { // bound checks are optimized away if self[idx] != other[idx] { return false; } + idx += 1; } true @@ -128,9 +135,10 @@ where // When each element can be compared byte-wise, we can compare all the bytes // from the whole size in one call to the intrinsics. -impl SlicePartialEq for [A] +#[rustc_const_unstable(feature = "const_cmp", issue = "143800")] +impl const SlicePartialEq for [A] where - A: BytewiseEq, + A: ~const BytewiseEq, { fn equal(&self, other: &[B]) -> bool { if self.len() != other.len() { diff --git a/library/core/src/str/traits.rs b/library/core/src/str/traits.rs index b9559c8317133..d68ec3ca59196 100644 --- a/library/core/src/str/traits.rs +++ b/library/core/src/str/traits.rs @@ -23,7 +23,8 @@ impl Ord for str { } #[stable(feature = "rust1", since = "1.0.0")] -impl PartialEq for str { +#[rustc_const_unstable(feature = "const_cmp", issue = "143800")] +impl const PartialEq for str { #[inline] fn eq(&self, other: &str) -> bool { self.as_bytes() == other.as_bytes() diff --git a/tests/ui/consts/const-compare-bytes-ub.rs b/tests/ui/consts/const-compare-bytes-ub.rs index 0bc8585a4eed1..7e3df92a2bf5a 100644 --- a/tests/ui/consts/const-compare-bytes-ub.rs +++ b/tests/ui/consts/const-compare-bytes-ub.rs @@ -1,6 +1,6 @@ //@ check-fail -#![feature(core_intrinsics)] +#![feature(core_intrinsics, const_cmp)] use std::intrinsics::compare_bytes; use std::mem::MaybeUninit; diff --git a/tests/ui/consts/const-compare-bytes.rs b/tests/ui/consts/const-compare-bytes.rs index cd5cdfd0400ec..9563375555cfd 100644 --- a/tests/ui/consts/const-compare-bytes.rs +++ b/tests/ui/consts/const-compare-bytes.rs @@ -1,6 +1,6 @@ //@ run-pass -#![feature(core_intrinsics)] +#![feature(core_intrinsics, const_cmp)] use std::intrinsics::compare_bytes; fn main() { diff --git a/tests/ui/traits/const-traits/const-impl-trait.rs b/tests/ui/traits/const-traits/const-impl-trait.rs index dc960422a4a41..da28d9a47c31e 100644 --- a/tests/ui/traits/const-traits/const-impl-trait.rs +++ b/tests/ui/traits/const-traits/const-impl-trait.rs @@ -1,7 +1,7 @@ //@ compile-flags: -Znext-solver //@ known-bug: #110395 -// Broken until we have `const PartialEq` impl in stdlib +// Broken until `(): const PartialEq` #![allow(incomplete_features)] #![feature(const_trait_impl, const_cmp, const_destruct)] diff --git a/tests/ui/traits/const-traits/match-non-const-eq.gated.stderr b/tests/ui/traits/const-traits/match-non-const-eq.gated.stderr deleted file mode 100644 index 89e59e5db6ed3..0000000000000 --- a/tests/ui/traits/const-traits/match-non-const-eq.gated.stderr +++ /dev/null @@ -1,12 +0,0 @@ -error[E0015]: cannot match on `str` in constant functions - --> $DIR/match-non-const-eq.rs:7:9 - | -LL | "a" => (), //FIXME [gated]~ ERROR can't compare `str` with `str` in const contexts - | ^^^ - | - = note: `str` cannot be compared in compile-time, and therefore cannot be used in `match`es - = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants - -error: aborting due to 1 previous error - -For more information about this error, try `rustc --explain E0015`. diff --git a/tests/ui/traits/const-traits/match-non-const-eq.rs b/tests/ui/traits/const-traits/match-non-const-eq.rs index 73f8af86bd050..03adb8dc5a4e5 100644 --- a/tests/ui/traits/const-traits/match-non-const-eq.rs +++ b/tests/ui/traits/const-traits/match-non-const-eq.rs @@ -1,11 +1,12 @@ -//@ known-bug: #110395 //@ revisions: stock gated -#![cfg_attr(gated, feature(const_trait_impl))] +#![cfg_attr(gated, feature(const_trait_impl, const_cmp))] +//@[gated] check-pass const fn foo(input: &'static str) { match input { - "a" => (), //FIXME [gated]~ ERROR can't compare `str` with `str` in const contexts - //FIXME ~^ ERROR cannot match on `str` in constant functions + "a" => (), + //[stock]~^ ERROR cannot match on `str` in constant functions + //[stock]~| ERROR `PartialEq` is not yet stable as a const trait _ => (), } } diff --git a/tests/ui/traits/const-traits/match-non-const-eq.stock.stderr b/tests/ui/traits/const-traits/match-non-const-eq.stock.stderr index 89e59e5db6ed3..afdd07311ea04 100644 --- a/tests/ui/traits/const-traits/match-non-const-eq.stock.stderr +++ b/tests/ui/traits/const-traits/match-non-const-eq.stock.stderr @@ -1,12 +1,26 @@ -error[E0015]: cannot match on `str` in constant functions +error[E0658]: cannot match on `str` in constant functions --> $DIR/match-non-const-eq.rs:7:9 | -LL | "a" => (), //FIXME [gated]~ ERROR can't compare `str` with `str` in const contexts +LL | "a" => (), | ^^^ | = note: `str` cannot be compared in compile-time, and therefore cannot be used in `match`es = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants + = note: see issue #67792 for more information + = help: add `#![feature(const_trait_impl)]` to the crate attributes to enable + = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date -error: aborting due to 1 previous error +error: `PartialEq` is not yet stable as a const trait + --> $DIR/match-non-const-eq.rs:7:9 + | +LL | "a" => (), + | ^^^ + | +help: add `#![feature(const_cmp)]` to the crate attributes to enable + | +LL + #![feature(const_cmp)] + | + +error: aborting due to 2 previous errors -For more information about this error, try `rustc --explain E0015`. +For more information about this error, try `rustc --explain E0658`.