1 files changed, 14 insertions, 0 deletions
diff --git a/src/test/ui/traits/negative-impls/negative-specializes-positive.rs b/src/test/ui/traits/negative-impls/negative-specializes-positive.rs
new file mode 100644
index 000000000..0e227691e
--- /dev/null
+++ b/src/test/ui/traits/negative-impls/negative-specializes-positive.rs
@@ -0,0 +1,14 @@
+#![feature(specialization)] //~ WARN the feature `specialization` is incomplete
+#![feature(negative_impls)]
+
+// Negative impl for u32 cannot "specialize" the base impl.
+trait MyTrait {}
+impl<T> MyTrait for T {}
+impl !MyTrait for u32 {} //~ ERROR E0751
+
+// The second impl specializes the first, no error.
+trait MyTrait2 {}
+impl<T> MyTrait2 for T {}
+impl MyTrait2 for u32 {}
+
+fn main() {}