tests/ui/impl-header-lifetime-elision/path-underscore.rs

   1 // Test that `impl MyTrait for Foo<'_>` works.
   2
   3 // run-pass
   4
   5 #![allow(warnings)]
   6
   7 trait MyTrait { }
   8
   9 struct Foo<'a> { x: &'a u32 }
  10
  11 impl MyTrait for Foo<'_> {
  12 }
  13
  14 fn impls_my_trait<T: MyTrait>() { }
  15
  16 fn impls_my_trait_val<T: MyTrait>(_: T) {
  17     impls_my_trait::<T>();
  18 }
  19
  20 fn random_where_clause()
  21 where for<'a> Foo<'a>: MyTrait { }
  22
  23 fn main() {
  24     let x = 22;
  25     let f = Foo { x: &x };
  26
  27     // This type is `Foo<'x>` for a local lifetime `'x`; so the impl
  28     // must apply to any lifetime to apply to this.
  29     impls_my_trait_val(f);
  30
  31     impls_my_trait::<Foo<'static>>();
  32
  33     random_where_clause();
  34 }