33 lines
904 B
Rust
33 lines
904 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 mk_identity<T>() -> @fn(T) -> T {
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let result: @fn(t: T) -> T = |t| t;
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result
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}
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fn main() {
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// type of r is @fn(X) -> X
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// for some fresh X
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let r = mk_identity();
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// @mut int <: X
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r(@mut 3);
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// @int <: X
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//
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// Here the type check fails because @const is gone and there is no
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// supertype.
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r(@3); //~ ERROR mismatched types
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// Here the type check succeeds.
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*r(@mut 3) = 4;
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}
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