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| 1 | +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
| 2 | +// file at the top-level directory of this distribution and at |
| 3 | +// http://rust-lang.org/COPYRIGHT. |
| 4 | +// |
| 5 | +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| 6 | +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| 7 | +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| 8 | +// option. This file may not be copied, modified, or distributed |
| 9 | +// except according to those terms. |
| 10 | + |
| 11 | +// Check that we properly record borrows when we are doing an |
| 12 | +// overloaded, autoderef of a value obtained via an overloaded index |
| 13 | +// operator. The accounting of the all the implicit things going on |
| 14 | +// here is rather subtle. Issue #20232. |
| 15 | + |
| 16 | +use std::ops::{Deref, Index}; |
| 17 | + |
| 18 | +struct MyVec<T> { x: T } |
| 19 | + |
| 20 | +impl<T> Index<usize> for MyVec<T> { |
| 21 | + type Output = T; |
| 22 | + fn index(&self, _: &usize) -> &T { |
| 23 | + &self.x |
| 24 | + } |
| 25 | +} |
| 26 | + |
| 27 | +struct MyPtr<T> { x: T } |
| 28 | + |
| 29 | +impl<T> Deref for MyPtr<T> { |
| 30 | + type Target = T; |
| 31 | + fn deref(&self) -> &T { |
| 32 | + &self.x |
| 33 | + } |
| 34 | +} |
| 35 | + |
| 36 | +struct Foo { f: usize } |
| 37 | + |
| 38 | +fn main() { |
| 39 | + let mut v = MyVec { x: MyPtr { x: Foo { f: 22 } } }; |
| 40 | + let i = &v[0].f; |
| 41 | + v = MyVec { x: MyPtr { x: Foo { f: 23 } } }; |
| 42 | + //~^ ERROR cannot assign to `v` |
| 43 | + read(*i); |
| 44 | +} |
| 45 | + |
| 46 | +fn read(_: usize) { } |
| 47 | + |
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