diff options
3 files changed, 45 insertions, 0 deletions
diff --git a/compiler/rustc_typeck/src/coherence/orphan.rs b/compiler/rustc_typeck/src/coherence/orphan.rs index fa3137567ad..917fc5631c4 100644 --- a/compiler/rustc_typeck/src/coherence/orphan.rs +++ b/compiler/rustc_typeck/src/coherence/orphan.rs @@ -230,6 +230,14 @@ impl ItemLikeVisitor<'v> for OrphanChecker<'tcx> { return; } } + + if let ty::Opaque(def_id, _) = *trait_ref.self_ty().kind() { + self.tcx + .sess + .struct_span_err(sp, "cannot implement trait on type alias impl trait") + .span_note(self.tcx.def_span(def_id), "type alias impl trait defined here") + .emit(); + } } } diff --git a/src/test/ui/type-alias-impl-trait/issue-76202-trait-impl-for-tait.rs b/src/test/ui/type-alias-impl-trait/issue-76202-trait-impl-for-tait.rs new file mode 100644 index 00000000000..9ce19536e79 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/issue-76202-trait-impl-for-tait.rs @@ -0,0 +1,23 @@ +// Regression test for issue #76202 +// Tests that we don't ICE when we have a trait impl on a TAIT. + +#![feature(type_alias_impl_trait)] + +trait Dummy {} +impl Dummy for () {} + +type F = impl Dummy; +fn f() -> F {} + +trait Test { + fn test(self); +} + +impl Test for F { //~ ERROR cannot implement trait + fn test(self) {} +} + +fn main() { + let x: F = f(); + x.test(); +} diff --git a/src/test/ui/type-alias-impl-trait/issue-76202-trait-impl-for-tait.stderr b/src/test/ui/type-alias-impl-trait/issue-76202-trait-impl-for-tait.stderr new file mode 100644 index 00000000000..8689ee53660 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/issue-76202-trait-impl-for-tait.stderr @@ -0,0 +1,14 @@ +error: cannot implement trait on type alias impl trait + --> $DIR/issue-76202-trait-impl-for-tait.rs:16:1 + | +LL | impl Test for F { + | ^^^^^^^^^^^^^^^ + | +note: type alias impl trait defined here + --> $DIR/issue-76202-trait-impl-for-tait.rs:9:10 + | +LL | type F = impl Dummy; + | ^^^^^^^^^^ + +error: aborting due to previous error + |