33 lines
829 B
Rust
33 lines
829 B
Rust
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// compile-flags: -Znext-solver
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#![feature(rustc_attrs)]
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// A test showcasing that the solver may need to
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// compute a goal which is already in the provisional
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// cache.
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//
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// However, given that `(): BInd` and `(): B` are currently distinct
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// goals, this is actually not possible right now.
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//
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// FIXME(-Znext-solver=coinductive): With the new coinduction approach
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// the same goal stack can be both inductive and coinductive, depending
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// on why we're proving a specific nested goal. Rewrite this test
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// at that point.
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#[rustc_coinductive]
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trait A {}
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#[rustc_coinductive]
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trait B {}
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trait BInd {}
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impl<T: ?Sized + B> BInd for T {}
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impl<T: ?Sized + BInd + B> A for T {}
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impl<T: ?Sized + BInd> B for T {}
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fn impls_a<T: A>() {}
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fn main() {
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impls_a::<()>();
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//~^ ERROR overflow evaluating the requirement `(): A`
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}
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