34 lines
669 B
Rust
34 lines
669 B
Rust
// compile-flags: -Ztrait-solver=next
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// check-pass
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// This tests checks that we update results in the provisional cache when
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// we pop a goal from the stack.
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#![feature(auto_traits)]
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auto trait Coinductive {}
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struct Foo<T>(T);
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struct Bar<T>(T);
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impl<T> Coinductive for Foo<T>
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where
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Bar<T>: Coinductive
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{}
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impl<T> Coinductive for Bar<T>
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where
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Foo<T>: Coinductive,
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Bar<T>: ConstrainInfer,
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{}
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trait ConstrainInfer {}
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impl ConstrainInfer for Bar<u8> {}
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impl ConstrainInfer for Foo<u16> {}
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fn impls<T: Coinductive>() -> T { todo!() }
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fn constrain<T: ConstrainInfer>(_: T) {}
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fn main() {
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// This should constrain `_` to `u8`.
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impls::<Foo<_>>();
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}
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