src/test/ui/nll/relate_tys/hr-fn-aba-as-aaa.rs

   1 // Test that the NLL `relate_tys` code correctly deduces that a
   2 // function returning always its first argument can be upcast to one
   3 // that returns either first or second argument.
   4 //
   5 // check-pass
   6 // compile-flags:-Zno-leak-check
   7
   8 fn make_it() -> for<'a, 'b> fn(&'a u32, &'b u32) -> &'a u32 {
   9     panic!()
  10 }
  11
  12 fn main() {
  13     let a: for<'a> fn(&'a u32, &'a u32) -> &'a u32 = make_it();
  14     drop(a);
  15 }