24 lines
669 B
Rust
24 lines
669 B
Rust
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// Tests that type alias impls traits do not leak auto-traits for
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// the purposes of coherence checking
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#![feature(type_alias_impl_trait)]
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trait OpaqueTrait { }
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impl<T> OpaqueTrait for T { }
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type OpaqueType = impl OpaqueTrait;
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fn mk_opaque() -> OpaqueType { () }
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#[derive(Debug)]
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struct D<T>(T);
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trait AnotherTrait { }
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impl<T: Send> AnotherTrait for T { }
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// This is in error, because we cannot assume that `OpaqueType: !Send`.
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// (We treat opaque types as "foreign types" that could grow more impls
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// in the future.)
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impl AnotherTrait for D<OpaqueType> {
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//~^ ERROR conflicting implementations of trait `AnotherTrait` for type `D<OpaqueType>`
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}
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fn main() {}
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