rust/tests/ui/unboxed-closures/unboxed-closures-infer-kind.rs
2023-01-11 09:32:08 +00:00

28 lines
482 B
Rust

// run-pass
// Test that we can infer the "kind" of an unboxed closure based on
// the expected type.
// 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);
}