37 lines
756 B
Rust
37 lines
756 B
Rust
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// Checks that various casts of pointers to trait objects wrapped in structures
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// work. Note that the metadata doesn't change when a DST is wrapped in a
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// structure, so these casts *are* fine.
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//
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// `unwrap` and `unwrap_nested` currently don't work due to a compiler limitation.
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trait A {}
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struct W<T: ?Sized>(T);
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struct X<T: ?Sized>(T);
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fn unwrap(a: *const W<dyn A>) -> *const dyn A {
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a as _
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//~^ error
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//~| error
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}
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fn unwrap_nested(a: *const W<W<dyn A>>) -> *const W<dyn A> {
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a as _
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//~^ error
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//~| error
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}
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fn rewrap(a: *const W<dyn A>) -> *const X<dyn A> {
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a as _
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}
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fn rewrap_nested(a: *const W<W<dyn A>>) -> *const W<X<dyn A>> {
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a as _
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}
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fn wrap(a: *const dyn A) -> *const W<dyn A> {
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a as _
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}
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fn main() {}
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