60 lines
1.3 KiB
Rust
60 lines
1.3 KiB
Rust
// Copyright 2012 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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struct Point {
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x: int,
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y: int,
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}
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impl Add<int,int> for Point {
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fn add(&self, z: &int) -> int {
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self.x + self.y + (*z)
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}
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}
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impl Point {
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pub fn times(&self, z: int) -> int {
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self.x * self.y * z
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}
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}
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fn a() {
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let mut p = Point {x: 3, y: 4};
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// ok (we can loan out rcvr)
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p + 3;
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p.times(3);
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}
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fn b() {
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let mut p = Point {x: 3, y: 4};
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// Here I create an outstanding loan and check that we get conflicts:
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let q = &mut p;
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p + 3; //~ ERROR cannot borrow `p`
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p.times(3); //~ ERROR cannot borrow `p`
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*q + 3; // OK to use the new alias `q`
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q.x += 1; // and OK to mutate it
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}
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fn c() {
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// Here the receiver is in aliased memory but due to write
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// barriers we can still consider it immutable.
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let q = @mut Point {x: 3, y: 4};
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*q + 3;
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q.times(3);
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}
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fn main() {
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}
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