5 #![feature(never_type)]
9 fn foo(x: u32, y: u32) -> u32 { x/y }
10 fn foo_diverges() -> ! { panic!() }
12 fn test_fn_ptr<T>(mut t: T)
13 where T: Fn(u32, u32) -> u32,
15 let as_fn = <T as Fn<(u32, u32)>>::call;
16 assert_eq!(as_fn(&t, (9, 3)), 3);
17 let as_fn_mut = <T as FnMut<(u32, u32)>>::call_mut;
18 assert_eq!(as_fn_mut(&mut t, (18, 3)), 6);
19 let as_fn_once = <T as FnOnce<(u32, u32)>>::call_once;
20 assert_eq!(as_fn_once(t, (24, 3)), 8);
23 fn assert_panics<F>(f: F) where F: FnOnce() {
24 let f = panic::AssertUnwindSafe(f);
25 let result = panic::catch_unwind(move || {
28 if let Ok(..) = result {
29 panic!("diverging function returned");
33 fn test_fn_ptr_panic<T>(mut t: T)
36 let as_fn = <T as Fn<()>>::call;
37 assert_panics(|| as_fn(&t, ()));
38 let as_fn_mut = <T as FnMut<()>>::call_mut;
39 assert_panics(|| as_fn_mut(&mut t, ()));
40 let as_fn_once = <T as FnOnce<()>>::call_once;
41 assert_panics(|| as_fn_once(t, ()));
46 test_fn_ptr(foo as fn(u32, u32) -> u32);
47 test_fn_ptr_panic(foo_diverges);
48 test_fn_ptr_panic(foo_diverges as fn() -> !);