40 lines
1.0 KiB
Rust
40 lines
1.0 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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fn main() {
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struct A {
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a: int,
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w: B,
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x: @B,
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z: @mut B
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}
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struct B {
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a: int
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}
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let mut p = A {
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a: 1,
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w: B {a: 1},
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x: @B {a: 1},
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z: @mut B {a: 1}
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};
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// even though `x` is not declared as a mutable field,
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// `p` as a whole is mutable, so it can be modified.
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p.a = 2;
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// this is true for an interior field too
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p.w.a = 2;
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// in these cases we pass through a box, so the mut
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// of the box is dominant
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p.x.a = 2; //~ ERROR cannot assign to immutable field
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p.z.a = 2;
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}
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