1 files changed, 32 insertions, 0 deletions
diff --git a/src/test/ui/consts/const_in_pattern/reject_non_partial_eq.rs b/src/test/ui/consts/const_in_pattern/reject_non_partial_eq.rs
new file mode 100644
index 000000000..a8216901c
--- /dev/null
+++ b/src/test/ui/consts/const_in_pattern/reject_non_partial_eq.rs
@@ -0,0 +1,32 @@
+// This test is illustrating the difference between how failing to derive
+// `PartialEq` is handled compared to failing to implement it at all.
+
+// See also RFC 1445
+
+#[derive(PartialEq, Eq)]
+struct Structural(u32);
+
+struct NoPartialEq(u32);
+
+struct NoDerive(u32);
+
+// This impl makes NoDerive irreflexive.
+impl PartialEq for NoDerive { fn eq(&self, _: &Self) -> bool { false } }
+
+impl Eq for NoDerive { }
+
+const NO_DERIVE_NONE: Option<NoDerive> = None;
+const NO_PARTIAL_EQ_NONE: Option<NoPartialEq> = None;
+
+fn main() {
+    match None {
+        NO_DERIVE_NONE => println!("NO_DERIVE_NONE"),
+        _ => panic!("whoops"),
+    }
+
+    match None {
+        NO_PARTIAL_EQ_NONE => println!("NO_PARTIAL_EQ_NONE"),
+        //~^ ERROR must be annotated with `#[derive(PartialEq, Eq)]`
+        _ => panic!("whoops"),
+    }
+}