mirror of https://github.com/rust-lang/rust
48 lines
1.3 KiB
Rust
48 lines
1.3 KiB
Rust
// WF check for impl Trait in associated type position.
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//
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//@ revisions: pass pass_next fail
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//@ [pass] check-pass
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//@ [pass_next] compile-flags: -Znext-solver
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//@ [pass_next] check-pass
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//@ [fail] check-fail
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#![feature(impl_trait_in_assoc_type)]
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// The hidden type here (`&'a T`) requires proving `T: 'a`.
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// We know it holds because of implied bounds from the impl header.
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#[cfg(any(pass, pass_next))]
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mod pass {
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trait Trait<Req> {
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type Opaque1;
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fn constrain_opaque1(req: Req) -> Self::Opaque1;
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}
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impl<'a, T> Trait<&'a T> for () {
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type Opaque1 = impl IntoIterator<Item = impl Sized + 'a>;
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fn constrain_opaque1(req: &'a T) -> Self::Opaque1 {
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[req]
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}
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}
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}
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// The hidden type here (`&'a T`) requires proving `T: 'a`,
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// but that is not known to hold in the impl.
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#[cfg(fail)]
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mod fail {
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trait Trait<'a, T> {
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type Opaque;
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fn constrain_opaque(req: &'a T) -> Self::Opaque;
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}
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impl<'a, T> Trait<'a, T> for () {
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type Opaque = impl Sized + 'a;
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//[fail]~^ ERROR the parameter type `T` may not live long enough
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//[fail]~| ERROR the parameter type `T` may not live long enough
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fn constrain_opaque(req: &'a T) -> Self::Opaque {
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req
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}
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}
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}
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fn main() {}
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