diff options
| -rw-r--r-- | compiler/rustc_borrowck/src/type_check/mod.rs | 3 | ||||
| -rw-r--r-- | tests/ui/nll/user-annotations/normalizing-user-annotation.rs | 31 |
2 files changed, 34 insertions, 0 deletions
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index 4d57e7aac58..3c95ebf9ffa 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -482,6 +482,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { } trace!(?curr_projected_ty); + // Need to renormalize `a` as typecheck may have failed to normalize + // higher-ranked aliases if normalization was ambiguous due to inference. + let a = self.normalize(a, locations); let ty = self.normalize(curr_projected_ty.ty, locations); self.relate_types(ty, v.xform(ty::Contravariant), a, locations, category)?; diff --git a/tests/ui/nll/user-annotations/normalizing-user-annotation.rs b/tests/ui/nll/user-annotations/normalizing-user-annotation.rs new file mode 100644 index 00000000000..fa8b3bfd577 --- /dev/null +++ b/tests/ui/nll/user-annotations/normalizing-user-annotation.rs @@ -0,0 +1,31 @@ +//@ check-pass +//@ revisions: current next +//@ ignore-compare-mode-next-solver (explicit revisions) +//@[next] compile-flags: -Znext-solver + +// Regression test for <https://github.com/rust-lang/rust/issues/141708>. + +// See description in there; this has to do with fundamental limitations +// to the old trait solver surrounding higher-ranked aliases with infer +// vars. This always worked in the new trait solver, but I added a revision +// just for good measure. + +trait Foo<'a> { + type Assoc; +} + +impl Foo<'_> for i32 { + type Assoc = u32; +} + +impl Foo<'_> for u32 { + type Assoc = u32; +} + +fn foo<'b: 'b, T: for<'a> Foo<'a>, F: for<'a> Fn(<T as Foo<'a>>::Assoc)>(_: F) -> (T, F) { + todo!() +} + +fn main() { + let (x, c): (i32, _) = foo::<'static, _, _>(|_| {}); +} |