dbf994bbaf
associated machinery. Future such attempts should go through lints anyhow. There is a fair amount of fallout in the compile-fail tests, as WF checking now occurs earlier in the process.
37 lines
1.4 KiB
Rust
37 lines
1.4 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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// The "projection gap" is particularly "fun" around higher-ranked
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// projections. This is because the current code is hard-coded to say
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// that a projection that contains escaping regions, like `<T as
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// Trait2<'y, 'z>>::Foo` where `'z` is bound, can only be found to
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// outlive a region if all components that appear free (`'y`, where)
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// outlive that region. However, we DON'T add those components to the
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// implied bounds set, but rather we treat projections with escaping
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// regions as opaque entities, just like projections without escaping
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// regions.
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trait Trait1<T> { }
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trait Trait2<'a, 'b> {
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type Foo;
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}
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// As a side-effect of the conservative process above, the type of
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// this argument `t` is not automatically considered well-formed,
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// since for it to be WF, we would need to know that `'y: 'x`, but we
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// do not infer that.
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fn callee<'x, 'y, T>(t: &'x for<'z> Trait1< <T as Trait2<'y, 'z>>::Foo >)
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//~^ ERROR reference has a longer lifetime than the data it references
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{
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}
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fn main() { }
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