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//@ run-pass
// Checks that the Fn trait hierarchy rules permit
// FnMut or FnOnce to be used where FnMut is implemented.
#![feature(unboxed_closures, fn_traits)]
struct S;
impl FnMut<(i32,)> for S {
extern "rust-call" fn call_mut(&mut self, (x,): (i32,)) -> i32 {
x * x
}
}
impl FnOnce<(i32,)> for S {
type Output = i32;
extern "rust-call" fn call_once(mut self, args: (i32,)) -> i32 { self.call_mut(args) }
}
fn call_it_mut<F:FnMut(i32)->i32>(f: &mut F, x: i32) -> i32 {
f(x)
}
fn call_it_once<F:FnOnce(i32)->i32>(f: F, x: i32) -> i32 {
f(x)
}
fn main() {
let y = call_it_mut(&mut S, 22);
let z = call_it_once(S, 22);
assert_eq!(y, z);
}
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