diff options
Diffstat (limited to 'src/test/ui/traits/negative-impls/rely-on-negative-impl-in-coherence.rs')
-rw-r--r-- | src/test/ui/traits/negative-impls/rely-on-negative-impl-in-coherence.rs | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/test/ui/traits/negative-impls/rely-on-negative-impl-in-coherence.rs b/src/test/ui/traits/negative-impls/rely-on-negative-impl-in-coherence.rs new file mode 100644 index 000000000..c1f96ab8c --- /dev/null +++ b/src/test/ui/traits/negative-impls/rely-on-negative-impl-in-coherence.rs @@ -0,0 +1,24 @@ +// check-pass + +#![feature(negative_impls)] +#![feature(with_negative_coherence)] + +// aux-build: foreign_trait.rs + +// Test that we cannot implement `LocalTrait` for `String`, +// even though there is a `String: !ForeignTrait` impl. +// +// This may not be the behavior we want long term, but it's the +// current semantics that we implemented so as to land `!Foo` impls +// quickly. See internals thread: +// +// https://internals.rust-lang.org/t/foo/11587/ + +extern crate foreign_trait; +use foreign_trait::ForeignTrait; + +trait LocalTrait {} +impl<T: ForeignTrait> LocalTrait for T {} +impl LocalTrait for String {} + +fn main() {} |