36 lines
1.1 KiB
Rust
36 lines
1.1 KiB
Rust
// Copyright 2014 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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trait Dummy { fn dummy(&self); }
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fn foo1<'a:'b,'b>(x: &'a mut (Dummy+'a)) -> &'b mut (Dummy+'b) {
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// Here, we are able to coerce
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x
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}
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fn foo2<'a:'b,'b>(x: &'b mut (Dummy+'a)) -> &'b mut (Dummy+'b) {
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// Here, we are able to coerce
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x
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}
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fn foo3<'a,'b>(x: &'a mut Dummy) -> &'b mut Dummy {
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// Without knowing 'a:'b, we can't coerce
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x //~ ERROR lifetime bound not satisfied
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//~^ ERROR cannot infer
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}
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struct Wrapper<T>(T);
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fn foo4<'a:'b,'b>(x: Wrapper<&'a mut Dummy>) -> Wrapper<&'b mut Dummy> {
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// We can't coerce because it is packed in `Wrapper`
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x //~ ERROR mismatched types
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}
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fn main() {}
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