diff --git a/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs b/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs index bde16fad821..d7b900ca02d 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs @@ -1191,11 +1191,14 @@ impl<'a, 'tcx> Visitor<'tcx> for FindInferSourceVisitor<'a, 'tcx> { have_turbofish, } = args; let generics = tcx.generics_of(generics_def_id); - if let Some(argument_index) = generics + if let Some(mut argument_index) = generics .own_substs(substs) .iter() .position(|&arg| self.generic_arg_contains_target(arg)) { + if generics.parent.is_none() && generics.has_self { + argument_index += 1; + } let substs = self.infcx.resolve_vars_if_possible(substs); let generic_args = &generics.own_substs_no_defaults(tcx, substs) [generics.own_counts().lifetimes..]; diff --git a/tests/ui/inference/need_type_info/concrete-impl.rs b/tests/ui/inference/need_type_info/concrete-impl.rs index 72e0e74f323..fc79e6201bd 100644 --- a/tests/ui/inference/need_type_info/concrete-impl.rs +++ b/tests/ui/inference/need_type_info/concrete-impl.rs @@ -7,10 +7,13 @@ struct Two; struct Struct; impl Ambiguous for Struct {} +//~^ NOTE multiple `impl`s satisfying `Struct: Ambiguous<_>` found impl Ambiguous for Struct {} fn main() { >::method(); //~^ ERROR type annotations needed + //~| NOTE cannot infer type of the type parameter `A` //~| ERROR type annotations needed + //~| NOTE infer type of the type parameter `A` } diff --git a/tests/ui/inference/need_type_info/concrete-impl.stderr b/tests/ui/inference/need_type_info/concrete-impl.stderr index aa32969950d..74c3f6cd5cf 100644 --- a/tests/ui/inference/need_type_info/concrete-impl.stderr +++ b/tests/ui/inference/need_type_info/concrete-impl.stderr @@ -1,20 +1,21 @@ error[E0282]: type annotations needed - --> $DIR/concrete-impl.rs:13:5 + --> $DIR/concrete-impl.rs:14:5 | LL | >::method(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `Self` declared on the trait `Ambiguous` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `A` declared on the trait `Ambiguous` error[E0283]: type annotations needed - --> $DIR/concrete-impl.rs:13:5 + --> $DIR/concrete-impl.rs:14:5 | LL | >::method(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `Self` declared on the trait `Ambiguous` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `A` declared on the trait `Ambiguous` | note: multiple `impl`s satisfying `Struct: Ambiguous<_>` found --> $DIR/concrete-impl.rs:9:1 | LL | impl Ambiguous for Struct {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +LL | LL | impl Ambiguous for Struct {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/tests/ui/inference/need_type_info/issue-109905.rs b/tests/ui/inference/need_type_info/issue-109905.rs new file mode 100644 index 00000000000..99d10a5eae0 --- /dev/null +++ b/tests/ui/inference/need_type_info/issue-109905.rs @@ -0,0 +1,25 @@ +// Test that we show the correct type parameter that couldn't be inferred and that we don't +// end up stating nonsense like "type parameter `'a`" which we used to do. + +trait Trait<'a, T> { + fn m(self); +} + +impl<'a, A> Trait<'a, A> for () { + fn m(self) {} +} + +fn qualified() { + <() as Trait<'static, _>>::m(()); + //~^ ERROR type annotations needed + //~| NOTE cannot infer type of the type parameter `T` + +} + +fn unqualified() { + Trait::<'static, _>::m(()); + //~^ ERROR type annotations needed + //~| NOTE cannot infer type of the type parameter `T` +} + +fn main() {} diff --git a/tests/ui/inference/need_type_info/issue-109905.stderr b/tests/ui/inference/need_type_info/issue-109905.stderr new file mode 100644 index 00000000000..fcdd50f1422 --- /dev/null +++ b/tests/ui/inference/need_type_info/issue-109905.stderr @@ -0,0 +1,15 @@ +error[E0282]: type annotations needed + --> $DIR/issue-109905.rs:13:5 + | +LL | <() as Trait<'static, _>>::m(()); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `T` declared on the trait `Trait` + +error[E0282]: type annotations needed + --> $DIR/issue-109905.rs:20:5 + | +LL | Trait::<'static, _>::m(()); + | ^^^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `T` declared on the trait `Trait` + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0282`.