25 lines
562 B
Rust
25 lines
562 B
Rust
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// The WF requirements of the *unnormalized* form of type annotations
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// can guide inference.
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//@ check-pass
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pub trait EqualTo {
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type Ty;
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}
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impl<X> EqualTo for X {
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type Ty = X;
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}
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trait MyTrait<U: EqualTo<Ty = Self>> {
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type Out;
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}
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impl<T, U: EqualTo<Ty = T>> MyTrait<U> for T {
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type Out = ();
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}
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fn main() {
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let _: <_ as MyTrait<u8>>::Out;
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// We shoud be able to infer a value for the inference variable above.
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// The WF of the unnormalized projection requires `u8: EqualTo<Ty = _>`,
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// which is sufficient to guide inference.
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}
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