Rollup merge of rust-lang#72556 - matthew-mcallister:trait-alias-inhe…

…rent-impl, r=estebank

Fix trait alias inherent impl resolution

Fixes rust-lang#60021 and fixes rust-lang#72415.

Obviously, the fix was very easy, but getting started with the testing and debugging rust compiler was an interesting experience. Now I can cross it off my bucket list!

src/librustc_typeck/check/method/probe.rs

@@ -795,6 +795,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
  fn assemble_inherent_candidates_from_param(&mut self, param_ty: ty::ParamTy) {
  // FIXME: do we want to commit to this behavior for param bounds?
+ debug!("assemble_inherent_candidates_from_param(param_ty={:?})", param_ty);
 
  let bounds =
  self.param_env.caller_bounds.iter().filter_map(|predicate| match predicate.kind() {
@@ -952,7 +953,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
  import_ids: import_ids.clone(),
  kind: TraitCandidate(new_trait_ref),
  },
- true,
+ false,
  );
  });
  } else {

src/test/ui/traits/trait-alias/issue-60021-assoc-method-resolve.rs

@@ -0,0 +1,19 @@
+// check-pass
+
+#![feature(trait_alias)]
+
+trait SomeTrait {
+ fn map(&self) {}
+}
+
+impl<T> SomeTrait for Option<T> {}
+
+trait SomeAlias = SomeTrait;
+
+fn main() {
+ let x = Some(123);
+ // This should resolve to the trait impl for Option
+ Option::map(x, |z| z);
+ // This should resolve to the trait impl for SomeTrait
+ SomeTrait::map(&x);
+}

src/test/ui/traits/trait-alias/issue-72415-assoc-const-resolve.rs

@@ -0,0 +1,14 @@
+// check-pass
+
+#![feature(trait_alias)]
+
+trait Bounded { const MAX: Self; }
+
+impl Bounded for u32 {
+ // This should correctly resolve to the associated const in the inherent impl of u32.
+ const MAX: Self = u32::MAX;
+}
+
+trait Num = Bounded + Copy;
+
+fn main() {}