rust/src/test/ui/nll/relate_tys/universe-violation.rs

18 lines
386 B
Rust
Raw Normal View History

// Test that the NLL `relate_tys` code correctly deduces that a
// function returning either argument CANNOT be upcast to one
// that returns always its first argument.
//
// compile-flags:-Zno-leak-check
#![feature(nll)]
fn make_it() -> fn(&'static u32) -> &'static u32 {
panic!()
}
fn main() {
let a: fn(_) -> _ = make_it();
let b: fn(&u32) -> &u32 = a;
drop(a);
}