src/test/ui/run-pass/issues/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 // run-pass
  12 #![feature(fn_traits, unboxed_closures)]
  13 use std::ops::Fn;
  14
  15 struct Foo<T>(T);
  16
  17 impl<T: Copy> Fn<()> for Foo<T> {
  18     extern "rust-call" fn call(&self, _: ()) -> T {
  19       match *self {
  20         Foo(t) => t
  21       }
  22     }
  23 }
  24
  25 impl<T: Copy> FnMut<()> for Foo<T> {
  26     extern "rust-call" fn call_mut(&mut self, _: ()) -> T {
  27         self.call(())
  28     }
  29 }
  30
  31 impl<T: Copy> FnOnce<()> for Foo<T> {
  32     type Output = T;
  33
  34     extern "rust-call" fn call_once(self, _: ()) -> T {
  35         self.call(())
  36     }
  37 }
  38
  39 fn main() {
  40   let t: u8 = 1;
  41   println!("{}", Foo(t)());
  42 }