rust/tests/ui/unboxed-closures/unboxed-closures-by-ref.rs

25 lines
392 B
Rust

//@ run-pass
// Test by-ref capture of environment in unboxed closure types
fn call_fn<F: Fn()>(f: F) {
f()
}
fn call_fn_mut<F: FnMut()>(mut f: F) {
f()
}
fn call_fn_once<F: FnOnce()>(f: F) {
f()
}
fn main() {
let mut x = 0_usize;
let y = 2_usize;
call_fn(|| assert_eq!(x, 0));
call_fn_mut(|| x += y);
call_fn_once(|| x += y);
assert_eq!(x, y * 2);
}