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//@ run-pass
// Checks that extern fn pointers implement the full range of Fn traits.
fn square(x: isize) -> isize { x * x }
fn call_it<F:Fn(isize)->isize>(f: &F, x: isize) -> isize {
f(x)
}
fn call_it_mut<F:FnMut(isize)->isize>(f: &mut F, x: isize) -> isize {
f(x)
}
fn call_it_once<F:FnOnce(isize)->isize>(f: F, x: isize) -> isize {
f(x)
}
fn main() {
let x = call_it(&square, 22);
let y = call_it_mut(&mut square, 22);
let z = call_it_once(square, 22);
assert_eq!(x, square(22));
assert_eq!(y, square(22));
assert_eq!(z, square(22));
}
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