rust/tests/ui/nll/relate_tys/hr-fn-aba-as-aaa.rs

18 lines
434 B
Rust

// Test that the NLL `relate_tys` code correctly deduces that a
// function returning always its first argument can be upcast to one
// that returns either first or second argument.
//
// check-pass
// compile-flags:-Zno-leak-check
#![allow(dropping_copy_types)]
fn make_it() -> for<'a, 'b> fn(&'a u32, &'b u32) -> &'a u32 {
panic!()
}
fn main() {
let a: for<'a> fn(&'a u32, &'a u32) -> &'a u32 = make_it();
drop(a);
}