mirror of https://github.com/rust-lang/rust
38 lines
1.1 KiB
Rust
38 lines
1.1 KiB
Rust
#![feature(auto_traits)]
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#![feature(negative_impls)]
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// Test for issue #56934 - that it is impossible to redundantly
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// implement an auto-trait for a trait object type that contains it.
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// Positive impl variant.
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auto trait Marker1 {}
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auto trait Marker2 {}
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trait Object: Marker1 {}
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// A supertrait marker is illegal...
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impl Marker1 for dyn Object + Marker2 {} //~ ERROR E0371
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//~^ ERROR E0321
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// ...and also a direct component.
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impl Marker2 for dyn Object + Marker2 {} //~ ERROR E0371
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//~^ ERROR E0321
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// A non-principal trait-object type is orphan even in its crate.
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unsafe impl Send for dyn Marker2 {} //~ ERROR E0117
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// Implementing a marker for a local trait object is forbidden by a special
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// orphan-like rule.
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impl Marker2 for dyn Object {} //~ ERROR E0321
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unsafe impl Send for dyn Object {} //~ ERROR E0321
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unsafe impl Send for dyn Object + Marker2 {} //~ ERROR E0321
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// Blanket impl that applies to dyn Object is equally problematic.
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auto trait Marker3 {}
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impl<T: ?Sized> Marker3 for T {} //~ ERROR E0321
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auto trait Marker4 {}
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impl<T> Marker4 for T {} // okay
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fn main() {}
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