// run-pass // Test by-ref capture of environment in unboxed closure types fn call_fn(f: F) { f() } fn call_fn_mut(mut f: F) { f() } fn call_fn_once(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); }