Link to the LLVM issue from a comment on SpecOptionPartialEq

scottmcm · scottmcm · commit 3e9d1e40cb2a · 2023-01-27T19:09:52.000-08:00
diff --git a/library/core/src/option.rs b/library/core/src/option.rs
@@ -2090,6 +2090,12 @@ impl<T: PartialEq> PartialEq for Option<T> {
     }
 }
 
+/// This specialization trait is a workaround for LLVM not currently (2023-01)
+/// being able to optimize this itself, even though Alive confirms that it would
+/// be legal to do so: <https://github.com/llvm/llvm-project/issues/52622>
+///
+/// Once that's fixed, `Option` should go back to deriving `PartialEq`, as
+/// it used to do before <https://github.com/rust-lang/rust/pull/103556>.
 #[unstable(feature = "spec_option_partial_eq", issue = "none", reason = "exposed only for rustc")]
 #[doc(hidden)]
 pub trait SpecOptionPartialEq: Sized {

Original file line number	Diff line number	Diff line change
`@@ -2090,6 +2090,12 @@ impl<T: PartialEq> PartialEq for Option<T> {`
`2090`	`2090`	`}`
`2091`	`2091`	`}`
`2092`	`2092`
	`2093`	`+/// This specialization trait is a workaround for LLVM not currently (2023-01)`
	`2094`	`+/// being able to optimize this itself, even though Alive confirms that it would`
	`2095`	`+/// be legal to do so: <https://github.com/llvm/llvm-project/issues/52622>`
	`2096`	`+///`
	`2097`	+/// Once that's fixed, `Option` should go back to deriving `PartialEq`, as
	`2098`	`+/// it used to do before <https://github.com/rust-lang/rust/pull/103556>.`
`2093`	`2099`	`#[unstable(feature = "spec_option_partial_eq", issue = "none", reason = "exposed only for rustc")]`
`2094`	`2100`	`#[doc(hidden)]`
`2095`	`2101`	`pub trait SpecOptionPartialEq: Sized {`