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23 lines
509 B
Rust
23 lines
509 B
Rust
// In contrast to `region-escape-via-bound-invariant`, in this case we
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// *can* return a value of type `&'x u32`, even though `'x` does not
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// appear in the bounds. This is because `&` is contravariant, and so
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// we are *actually* returning a `&'y u32`.
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//
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// See https://github.com/rust-lang/rust/issues/46541 for more details.
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// run-pass
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#![allow(dead_code)]
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trait Trait<'a> { }
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impl<'a, 'b> Trait<'b> for &'a u32 { }
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fn foo<'x, 'y>(x: &'x u32) -> impl Trait<'y>
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where 'x: 'y
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{
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x
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}
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fn main() { }
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