mirror of https://github.com/rust-lang/rust
32 lines
597 B
Rust
32 lines
597 B
Rust
//@ check-pass
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//@ compile-flags: -Znext-solver
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trait Test {
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type Assoc;
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}
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fn transform<T: Test>(x: Inv<T>) -> Inv<T::Assoc> {
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todo!()
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}
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impl Test for i32 {
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type Assoc = i32;
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}
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impl Test for String {
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type Assoc = String;
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}
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struct Inv<T>(Option<*mut T>);
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fn main() {
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let mut x: Inv<_> = Inv(None);
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// This ends up equating `Inv<?x>` with `Inv<<?x as Test>::Assoc>`
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// which fails the occurs check when generalizing `?x`.
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//
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// We end up emitting a delayed obligation, causing this to still
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// succeed.
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x = transform(x);
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x = Inv::<i32>(None);
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}
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