src/test/run-pass/overloaded/overloaded-index-autoderef.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 #![allow(stable_features)]
  13
  14 // Test overloaded indexing combined with autoderef.
  15
  16 #![feature(box_syntax, core)]
  17
  18 use std::ops::{Index, IndexMut};
  19
  20 struct Foo {
  21     x: isize,
  22     y: isize,
  23 }
  24
  25 impl Index<isize> for Foo {
  26     type Output = isize;
  27
  28     fn index(&self, z: isize) -> &isize {
  29         if z == 0 {
  30             &self.x
  31         } else {
  32             &self.y
  33         }
  34     }
  35 }
  36
  37 impl IndexMut<isize> for Foo {
  38     fn index_mut(&mut self, z: isize) -> &mut isize {
  39         if z == 0 {
  40             &mut self.x
  41         } else {
  42             &mut self.y
  43         }
  44     }
  45 }
  46
  47 trait Int {
  48     fn get(self) -> isize;
  49     fn get_from_ref(&self) -> isize;
  50     fn inc(&mut self);
  51 }
  52
  53 impl Int for isize {
  54     fn get(self) -> isize { self }
  55     fn get_from_ref(&self) -> isize { *self }
  56     fn inc(&mut self) { *self += 1; }
  57 }
  58
  59 fn main() {
  60     let mut f: Box<_> = box Foo {
  61         x: 1,
  62         y: 2,
  63     };
  64
  65     assert_eq!(f[1], 2);
  66
  67     f[0] = 3;
  68
  69     assert_eq!(f[0], 3);
  70
  71     // Test explicit IndexMut where `f` must be autoderef:
  72     {
  73         let p = &mut f[1];
  74         *p = 4;
  75     }
  76
  77     // Test explicit Index where `f` must be autoderef:
  78     {
  79         let p = &f[1];
  80         assert_eq!(*p, 4);
  81     }
  82
  83     // Test calling methods with `&mut self`, `self, and `&self` receivers:
  84     f[1].inc();
  85     assert_eq!(f[1].get(), 5);
  86     assert_eq!(f[1].get_from_ref(), 5);
  87 }