1 files changed, 24 insertions, 0 deletions
diff --git a/tests/ui/coherence/coherence-multidispatch-tuple.rs b/tests/ui/coherence/coherence-multidispatch-tuple.rs
new file mode 100644
index 00000000000..fa1d4bbb496
--- /dev/null
+++ b/tests/ui/coherence/coherence-multidispatch-tuple.rs
@@ -0,0 +1,24 @@
+// run-pass
+#![allow(unused_imports)]
+// pretty-expanded FIXME #23616
+
+use std::fmt::Debug;
+use std::default::Default;
+
+// Test that an impl for homogeneous pairs does not conflict with a
+// heterogeneous pair.
+
+trait MyTrait {
+    fn get(&self) -> usize;
+}
+
+impl<T> MyTrait for (T,T) {
+    fn get(&self) -> usize { 0 }
+}
+
+impl MyTrait for (usize,isize) {
+    fn get(&self) -> usize { 0 }
+}
+
+fn main() {
+}