src/test/run-pass/overloaded-calls-simple.rs

   1 // Copyright 2012 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
  12 #![feature(lang_items, unboxed_closures, fn_traits)]
  13
  14 use std::ops::{Fn, FnMut, FnOnce};
  15
  16 struct S1 {
  17     x: i32,
  18     y: i32,
  19 }
  20
  21 impl FnMut<(i32,)> for S1 {
  22     extern "rust-call" fn call_mut(&mut self, (z,): (i32,)) -> i32 {
  23         self.x * self.y * z
  24     }
  25 }
  26
  27 impl FnOnce<(i32,)> for S1 {
  28     type Output = i32;
  29     extern "rust-call" fn call_once(mut self, args: (i32,)) -> i32 {
  30         self.call_mut(args)
  31     }
  32 }
  33
  34 struct S2 {
  35     x: i32,
  36     y: i32,
  37 }
  38
  39 impl Fn<(i32,)> for S2 {
  40     extern "rust-call" fn call(&self, (z,): (i32,)) -> i32 {
  41         self.x * self.y * z
  42     }
  43 }
  44
  45 impl FnMut<(i32,)> for S2 {
  46     extern "rust-call" fn call_mut(&mut self, args: (i32,)) -> i32 { self.call(args) }
  47 }
  48
  49 impl FnOnce<(i32,)> for S2 {
  50     type Output = i32;
  51     extern "rust-call" fn call_once(self, args: (i32,)) -> i32 { self.call(args) }
  52 }
  53
  54 struct S3 {
  55     x: i32,
  56     y: i32,
  57 }
  58
  59 impl FnOnce<(i32,i32)> for S3 {
  60     type Output = i32;
  61     extern "rust-call" fn call_once(self, (z,zz): (i32,i32)) -> i32 {
  62         self.x * self.y * z * zz
  63     }
  64 }
  65
  66 fn main() {
  67     let mut s = S1 {
  68         x: 3,
  69         y: 3,
  70     };
  71     let ans = s(3);
  72
  73     assert_eq!(ans, 27);
  74     let s = S2 {
  75         x: 3,
  76         y: 3,
  77     };
  78     let ans = s.call((3,));
  79     assert_eq!(ans, 27);
  80
  81     let s = S3 {
  82         x: 3,
  83         y: 3,
  84     };
  85     let ans = s(3, 1);
  86     assert_eq!(ans, 27);
  87 }