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|
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) { }
|
