37 lines
1.3 KiB
Rust
37 lines
1.3 KiB
Rust
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// 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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// Tests that callees correctly infer an ordering between free regions
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// that appear in their parameter list. See also
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// regions-free-region-ordering-caller.rs
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fn ordering1<'a, 'b>(x: &'a &'b uint) -> &'a uint {
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// It is safe to assume that 'a <= 'b due to the type of x
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let y: &'b uint = &**x;
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return y;
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}
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fn ordering2<'a, 'b>(x: &'a &'b uint, y: &'a uint) -> &'b uint {
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// However, it is not safe to assume that 'b <= 'a
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&*y //~ ERROR cannot infer an appropriate lifetime
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}
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fn ordering3<'a, 'b>(x: &'a uint, y: &'b uint) -> &'a &'b uint {
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// Do not infer an ordering from the return value.
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let z: &'b uint = &*x;
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//~^ ERROR cannot infer an appropriate lifetime due to conflicting requirements
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fail!();
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}
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fn ordering4<'a, 'b>(a: &'a uint, b: &'b uint, x: &fn(&'a &'b uint)) {
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let z: Option<&'a &'b uint> = None;
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}
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fn main() {}
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