1 // run-pass
2 // Checks that the Fn trait hierarchy rules permit
3 // FnMut or FnOnce to be used where FnMut is implemented.
4
5 #![feature(unboxed_closures, fn_traits)]
6
7 struct S;
8
9 impl FnMut<(i32,)> for S {
call_mut(&mut self, (x,): (i32,)) -> i3210 extern "rust-call" fn call_mut(&mut self, (x,): (i32,)) -> i32 {
11 x * x
12 }
13 }
14
15 impl FnOnce<(i32,)> for S {
16 type Output = i32;
17
call_once(mut self, args: (i32,)) -> i3218 extern "rust-call" fn call_once(mut self, args: (i32,)) -> i32 { self.call_mut(args) }
19 }
20
call_it_mut<F:FnMut(i32)->i32>(f: &mut F, x: i32) -> i3221 fn call_it_mut<F:FnMut(i32)->i32>(f: &mut F, x: i32) -> i32 {
22 f(x)
23 }
24
call_it_once<F:FnOnce(i32)->i32>(f: F, x: i32) -> i3225 fn call_it_once<F:FnOnce(i32)->i32>(f: F, x: i32) -> i32 {
26 f(x)
27 }
28
main()29 fn main() {
30 let y = call_it_mut(&mut S, 22);
31 let z = call_it_once(S, 22);
32 assert_eq!(y, z);
33 }
34