src/test/run-pass/overloaded/overloaded-calls-zero-args.rs

   1 // run-pass
   2
   3 #![feature(unboxed_closures, fn_traits)]
   4
   5 use std::ops::FnMut;
   6
   7 struct S {
   8     x: i32,
   9     y: i32,
  10 }
  11
  12 impl FnMut<()> for S {
  13     extern "rust-call" fn call_mut(&mut self, (): ()) -> i32 {
  14         self.x * self.y
  15     }
  16 }
  17
  18 impl FnOnce<()> for S {
  19     type Output = i32;
  20     extern "rust-call" fn call_once(mut self, args: ()) -> i32 { self.call_mut(args) }
  21 }
  22
  23 fn main() {
  24     let mut s = S {
  25         x: 3,
  26         y: 3,
  27     };
  28     let ans = s();
  29     assert_eq!(ans, 9);
  30 }