src/test/run-pass/issue-13655.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 #![feature(unboxed_closures, core)]
  12 use std::ops::Fn;
  13
  14 struct Foo<T>(T);
  15
  16 impl<T: Copy> Fn<()> for Foo<T> {
  17     extern "rust-call" fn call(&self, _: ()) -> T {
  18       match *self {
  19         Foo(t) => t
  20       }
  21     }
  22 }
  23
  24 impl<T: Copy> FnMut<()> for Foo<T> {
  25     extern "rust-call" fn call_mut(&mut self, _: ()) -> T {
  26         self.call(())
  27     }
  28 }
  29
  30 impl<T: Copy> FnOnce<()> for Foo<T> {
  31     type Output = T;
  32
  33     extern "rust-call" fn call_once(self, _: ()) -> T {
  34         self.call(())
  35     }
  36 }
  37
  38 fn main() {
  39   let t: u8 = 1;
  40   println!("{}", Foo(t)());
  41 }