| // Copyright 2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use std::ops::{Index, IndexMut}; |
| |
| struct Foo { |
| x: isize, |
| y: isize, |
| } |
| |
| impl<'a> Index<&'a String> for Foo { |
| type Output = isize; |
| |
| fn index(&self, z: &String) -> &isize { |
| if *z == "x" { |
| &self.x |
| } else { |
| &self.y |
| } |
| } |
| } |
| |
| impl<'a> IndexMut<&'a String> for Foo { |
| fn index_mut(&mut self, z: &String) -> &mut isize { |
| if *z == "x" { |
| &mut self.x |
| } else { |
| &mut self.y |
| } |
| } |
| } |
| |
| struct Bar { |
| x: isize, |
| } |
| |
| impl Index<isize> for Bar { |
| type Output = isize; |
| |
| fn index<'a>(&'a self, z: isize) -> &'a isize { |
| &self.x |
| } |
| } |
| |
| fn main() { |
| let mut f = Foo { |
| x: 1, |
| y: 2, |
| }; |
| let mut s = "hello".to_string(); |
| let rs = &mut s; |
| println!("{}", f[&s]); |
| //~^ ERROR cannot borrow `s` as immutable because it is also borrowed as mutable |
| f[&s] = 10; |
| //~^ ERROR cannot borrow `s` as immutable because it is also borrowed as mutable |
| let s = Bar { |
| x: 1, |
| }; |
| s[2] = 20; |
| //~^ ERROR cannot assign to immutable indexed content |
| } |