| use std::ops::{Index, IndexMut}; |
| |
| struct Foo { |
| x: isize, |
| y: isize, |
| } |
| |
| impl Index<String> for Foo { |
| type Output = isize; |
| |
| fn index(&self, z: String) -> &isize { |
| if z == "x" { |
| &self.x |
| } else { |
| &self.y |
| } |
| } |
| } |
| |
| impl IndexMut<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 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]); |
| |
| use_mut(rs); |
| } |
| |
| fn use_mut<T>(_: &mut T) { } |