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// Tests that unsafe extern fn pointers do not implement any Fn traits.
use std::ops::{Fn, FnMut, FnOnce};
unsafe fn square(x: isize) -> isize {
x * x
}
// note: argument type here is `isize`, not `&isize`
fn call_it<F: Fn(&isize) -> isize>(_: &F, _: isize) -> isize {
0
}
fn call_it_mut<F: FnMut(&isize) -> isize>(_: &mut F, _: isize) -> isize {
0
}
fn call_it_once<F: FnOnce(&isize) -> isize>(_: F, _: isize) -> isize {
0
}
fn a() {
let x = call_it(&square, 22);
//~^ ERROR E0277
}
fn b() {
let y = call_it_mut(&mut square, 22);
//~^ ERROR E0277
}
fn c() {
let z = call_it_once(square, 22);
//~^ ERROR E0277
}
fn main() {}
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