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.
6 // compile-flags:-Zno-leak-check
8 fn make_it() -> for<'a, 'b> fn(&'a u32, &'b u32) -> &'a u32 {
13 let a: for<'a> fn(&'a u32, &'a u32) -> &'a u32 = make_it();