add comment about opaque types

lcnr · lcnr · commit f5f67618e25b · 2022-11-15T13:50:13.000+01:00
diff --git a/compiler/rustc_const_eval/src/util/compare_types.rs b/compiler/rustc_const_eval/src/util/compare_types.rs
@@ -28,6 +28,9 @@ pub fn is_equal_up_to_subtyping<'tcx>(
 }
 
 /// Returns whether `src` is a subtype of `dest`, i.e. `src <: dest`.
+///
+/// This mostly ignores opaque types as it can be used in constraining contexts
+/// while still computing the final underlying type.
 pub fn is_subtype<'tcx>(
     tcx: TyCtxt<'tcx>,
     param_env: ParamEnv<'tcx>,

Original file line number	Diff line number	Diff line change
`@@ -28,6 +28,9 @@ pub fn is_equal_up_to_subtyping<'tcx>(`
`28`	`28`	`}`
`29`	`29`
`30`	`30`	/// Returns whether `src` is a subtype of `dest`, i.e. `src <: dest`.
	`31`	`+///`
	`32`	`+/// This mostly ignores opaque types as it can be used in constraining contexts`
	`33`	`+/// while still computing the final underlying type.`
`31`	`34`	`pub fn is_subtype<'tcx>(`
`32`	`35`	`tcx: TyCtxt<'tcx>,`
`33`	`36`	`param_env: ParamEnv<'tcx>,`