tests/ui/object-lifetime/object-lifetime-default-dyn-binding-nonstatic3.rs

   1 // Test that `dyn Bar<Item = XX>` uses `'static` as the default object
   2 // lifetime bound for the type `XX`.
   3
   4 trait Foo<'a> {
   5     type Item: ?Sized;
   6
   7     fn item(&self) -> Box<Self::Item> { panic!() }
   8 }
   9
  10 trait Bar { }
  11
  12 fn is_static<T>(_: T) where T: 'static { }
  13
  14 // Here, we should default to `dyn Bar + 'static`, but the current
  15 // code forces us into a conservative, hacky path.
  16 fn bar(x: &str) -> &dyn Foo<Item = dyn Bar> { &() }
  17 //~^ ERROR please supply an explicit bound
  18
  19 fn main() {
  20     let s = format!("foo");
  21     let r = bar(&s);
  22     is_static(r.item());
  23 }