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