src/test/ui/associated-types/impl-trait-return-missing-constraint.rs

   1 trait Foo {
   2     type Item;
   3 }
   4
   5 trait Bar: Foo {}
   6
   7 struct S;
   8
   9 impl Foo for S {
  10     type Item = i32;
  11 }
  12 impl Bar for S {}
  13
  14 struct T;
  15
  16 impl Foo for T {
  17     type Item = u32;
  18 }
  19 impl Bar for T {}
  20
  21 fn bar() -> impl Bar {
  22     T
  23 }
  24
  25 fn baz() -> impl Bar<Item = i32> {
  26     //~^ ERROR type mismatch resolving `<impl Bar as Foo>::Item == i32`
  27     bar()
  28 }
  29
  30 fn main() {
  31     let _ = baz();
  32 }