src/test/ui/traits/trait-static-method-generic-inference.rs

   1 // Issue #3902. We are (at least currently) unable to infer `Self`
   2 // based on `T`, even though there is only a single impl, because of
   3 // the possibility of associated types and other things (basically: no
   4 // constraints on `Self` here at all).
   5
   6 mod base {
   7     pub trait HasNew<T> {
   8         fn new() -> T;
   9         fn dummy(&self) { }
  10     }
  11
  12     pub struct Foo {
  13         dummy: (),
  14     }
  15
  16     impl HasNew<Foo> for Foo {
  17         fn new() -> Foo {
  18             Foo { dummy: () }
  19         }
  20     }
  21 }
  22
  23 pub fn foo() {
  24     let _f: base::Foo = base::HasNew::new();
  25     //~^ ERROR type annotations needed
  26 }
  27
  28 fn main() { }