tests

src/test/ui/late-bound-lifetimes/auxiliary/upstream_alias.rs

@@ -0,0 +1,5 @@
+pub trait Trait<'a> {
+    type Assoc;
+}
+
+pub type Alias<'a, T> = <T as Trait<'a>>::Assoc;

src/test/ui/late-bound-lifetimes/cross_crate_alias.rs

@@ -0,0 +1,10 @@
+// aux-build:upstream_alias.rs
+// check-pass
+
+extern crate upstream_alias;
+
+fn foo<'a, T: for<'b> upstream_alias::Trait<'b>>(_: upstream_alias::Alias<'a, T>) -> &'a () {
+    todo!()
+}
+
+fn main() {}

src/test/ui/late-bound-lifetimes/late_bound_through_alias.rs

@@ -0,0 +1,16 @@
+// check-pass
+
+fn f(_: X) -> X {
+    unimplemented!()
+}
+
+fn g<'a>(_: X<'a>) -> X<'a> {
+    unimplemented!()
+}
+
+type X<'a> = &'a ();
+
+fn main() {
+    let _: for<'a> fn(X<'a>) -> X<'a> = g;
+    let _: for<'a> fn(X<'a>) -> X<'a> = f;
+}