src/test/run-pass/unboxed-closures-by-ref.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // Test by-ref capture of environment in unboxed closure types
  12
  13 fn call_fn<F: Fn()>(f: F) {
  14     f()
  15 }
  16
  17 fn call_fn_mut<F: FnMut()>(mut f: F) {
  18     f()
  19 }
  20
  21 fn call_fn_once<F: FnOnce()>(f: F) {
  22     f()
  23 }
  24
  25 fn main() {
  26     let mut x = 0_usize;
  27     let y = 2_usize;
  28
  29     call_fn(|| assert_eq!(x, 0));
  30     call_fn_mut(|| x += y);
  31     call_fn_once(|| x += y);
  32     assert_eq!(x, y * 2);
  33 }