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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 02:49:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 02:49:50 +0000 |
commit | 9835e2ae736235810b4ea1c162ca5e65c547e770 (patch) | |
tree | 3fcebf40ed70e581d776a8a4c65923e8ec20e026 /tests/ui/coherence/coherence-overlap-negative-impls.rs | |
parent | Releasing progress-linux version 1.70.0+dfsg2-1~progress7.99u1. (diff) | |
download | rustc-9835e2ae736235810b4ea1c162ca5e65c547e770.tar.xz rustc-9835e2ae736235810b4ea1c162ca5e65c547e770.zip |
Merging upstream version 1.71.1+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/coherence/coherence-overlap-negative-impls.rs')
-rw-r--r-- | tests/ui/coherence/coherence-overlap-negative-impls.rs | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/tests/ui/coherence/coherence-overlap-negative-impls.rs b/tests/ui/coherence/coherence-overlap-negative-impls.rs new file mode 100644 index 000000000..cd1df53a5 --- /dev/null +++ b/tests/ui/coherence/coherence-overlap-negative-impls.rs @@ -0,0 +1,41 @@ +// check-pass +// known-bug: #74629 + +// Should fail. The `0` and `1` impls overlap, violating coherence. Eg, with +// `T = Test, F = ()`, all bounds are true, making both impls applicable. +// `Test: Fold<Nil>`, `Test: Fold<()>` are true because of `2`. +// `Is<Test>: NotNil` is true because of `auto trait` and lack of negative impl. + +#![feature(negative_impls)] +#![feature(auto_traits)] + +struct Nil; +struct Cons<H>(H); +struct Test; + +trait Fold<F> {} + +impl<T, F> Fold<F> for Cons<T> // 0 +where + T: Fold<Nil>, +{} + +impl<T, F> Fold<F> for Cons<T> // 1 +where + T: Fold<F>, + private::Is<T>: private::NotNil, +{} + +impl<F> Fold<F> for Test {} // 2 + +mod private { + use crate::Nil; + + pub struct Is<T>(T); + pub auto trait NotNil {} + + #[allow(suspicious_auto_trait_impls)] + impl !NotNil for Is<Nil> {} +} + +fn main() {} |