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20 lines
460 B
Rust
20 lines
460 B
Rust
// revisions: current next
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//[next] compile-flags: -Znext-solver
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#![feature(type_alias_impl_trait)]
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type A = impl Foo; //[current]~ ERROR unconstrained opaque type
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type B = impl Foo;
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trait Foo {}
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fn muh(x: A) -> B {
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x // B's hidden type is A (opaquely)
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//[current]~^ ERROR opaque type's hidden type cannot be another opaque type
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//[next]~^^ ERROR type annotations needed: cannot satisfy `A <: B`
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}
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struct Bar;
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impl Foo for Bar {}
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fn main() {}
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