28 lines
973 B
Rust
28 lines
973 B
Rust
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// Test for a less than ideal interaction of implied bounds and normalization.
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trait Tr {
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type Ty;
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}
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impl<T: 'static> Tr for T {
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type Ty = &'static T;
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}
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// `<&'a u8 as Tr>::Ty` should cause an error because `&'a u8: Tr` doesn't hold for
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// all possible 'a. However, we consider normalized types for implied bounds.
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//
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// We normalize this projection to `&'static &'a u8` and add a nested `&'a u8: 'static`
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// bound. This bound is then proven using the implied bounds for `&'static &'a u8` which
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// we only get by normalizing in the first place.
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fn test<'a>(x: &'a u8, _wf: <&'a u8 as Tr>::Ty) -> &'static u8 { x }
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fn main() {
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// This works as we have 'static references due to promotion.
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let _: &'static u8 = test(&3, &&3);
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// This causes an error because the projection requires 'a to be 'static.
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// It would be unsound if this compiled.
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let x: u8 = 3;
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let _: &'static u8 = test(&x, &&3);
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//~^ ERROR `x` does not live long enough
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}
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