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+An "or" pattern was used where the variable bindings are not consistently bound
+across patterns.
+
+Erroneous code example:
+
+```compile_fail,E0409
+let x = (0, 2);
+match x {
+    (0, ref y) | (y, 0) => { /* use y */} // error: variable `y` is bound with
+                                          //        different mode in pattern #2
+                                          //        than in pattern #1
+    _ => ()
+}
+```
+
+Here, `y` is bound by-value in one case and by-reference in the other.
+
+To fix this error, just use the same mode in both cases.
+Generally using `ref` or `ref mut` where not already used will fix this:
+
+```
+let x = (0, 2);
+match x {
+    (0, ref y) | (ref y, 0) => { /* use y */}
+    _ => ()
+}
+```
+
+Alternatively, split the pattern:
+
+```
+let x = (0, 2);
+match x {
+    (y, 0) => { /* use y */ }
+    (0, ref y) => { /* use y */}
+    _ => ()
+}
+```