diff options
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/project.rs | 2 | ||||
| -rw-r--r-- | tests/ui/type-alias-impl-trait/nested_inference_failure.rs | 26 |
2 files changed, 27 insertions, 1 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index dd4e69efe37..abbc2066eac 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -2466,7 +2466,7 @@ fn confirm_param_env_candidate<'cx, 'tcx>( debug!(?cache_projection, ?obligation_projection); match infcx.at(cause, param_env).eq( - DefineOpaqueTypes::No, + DefineOpaqueTypes::Yes, cache_projection, obligation_projection, ) { diff --git a/tests/ui/type-alias-impl-trait/nested_inference_failure.rs b/tests/ui/type-alias-impl-trait/nested_inference_failure.rs new file mode 100644 index 00000000000..16b78f18aa3 --- /dev/null +++ b/tests/ui/type-alias-impl-trait/nested_inference_failure.rs @@ -0,0 +1,26 @@ +// check-pass + +//! This test checks that we can successfully infer +//! the hidden type of `FooImpl` to be `Foo<i32, {closure}>` +//! and `ImplT` to be `i32`. This test used to fail, because +//! we were unable to make the connection that the closure +//! argument is the same as the first argument of `Foo`. + +#![feature(type_alias_impl_trait)] + +use std::fmt::Debug; +use std::marker::PhantomData; + +struct Foo<T: Debug, F: FnOnce(T)> { + f: F, + _phantom: PhantomData<T>, +} + +type ImplT = impl Debug; +type FooImpl = Foo<ImplT, impl FnOnce(ImplT)>; + +fn bar() -> FooImpl { + Foo::<i32, _> { f: |_| (), _phantom: PhantomData } +} + +fn main() {} |