// 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 or the MIT license // , 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 Index for Foo { type Output = isize; fn index(&self, z: String) -> &isize { if z == "x" { &self.x } else { &self.y } } } impl IndexMut 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 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 move out of `s` because it is borrowed f[s] = 10; //~^ ERROR cannot move out of `s` because it is borrowed //~| ERROR use of moved value: `s` let s = Bar { x: 1, }; let i = 2; let _j = &i; println!("{}", s[i]); // no error, i is copy println!("{}", s[i]); }