Treat str as containing [u8] for auto trait purposes

2023-02-11 23:01:22 +00:00
parent 31448badfd
commit 3560e65c44
4 changed files with 35 additions and 2 deletions
--- a/compiler/rustc_trait_selection/src/solve/trait_goals/structural_traits.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals/structural_traits.rs
@@ -20,12 +20,14 @@ pub(super) fn instantiate_constituent_tys_for_auto_trait<'tcx>(
        | ty::Float(_)
        | ty::FnDef(..)
        | ty::FnPtr(_)
-        | ty::Str
        | ty::Error(_)
        | ty::Infer(ty::IntVar(_) | ty::FloatVar(_))
        | ty::Never
        | ty::Char => Ok(vec![]),

+        // Treat this like `struct str([u8]);`
+        ty::Str => Ok(vec![tcx.mk_slice(tcx.types.u8)]),
+
        ty::Dynamic(..)
        | ty::Param(..)
        | ty::Foreign(..)