33 lines
900 B
Rust
33 lines
900 B
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 reproduce<T:Copy>(t: T) -> fn@() -> T {
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fn@() -> T { t }
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}
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fn main() {
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// type of x is the variable X,
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// with the lower bound @mut int
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let x = @mut 3;
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// type of r is fn@() -> X
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let r = reproduce(x);
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// Requires that X be a subtype of
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// @mut int.
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let f: @mut int = r();
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// OK.
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let g: @const int = r();
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// Bad.
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let h: @int = r(); //~ ERROR (values differ in mutability)
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}
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