User-defined operators on structs

test/libsolidity/syntaxTests/controlFlow/userDefinedOperators/binary_operator_struct.sol

@@ -0,0 +1,17 @@
+struct S { Z z; }
+struct Z { int x; }
+
+using {addS as +} for S;
+using {addZ as +} for Z;
+
+function addS(S memory, S memory) pure returns (S memory) {}
+function addZ(Z memory, Z memory) pure returns (Z memory) { revert(); }
+
+contract C {
+    function f() public pure {
+        S(Z(1)) + S(Z(2) + Z(3));
+        S(Z(4)) + S(Z(5)); // Unreachable
+    }
+}
+// ----
+// Warning 5740: (310-327): Unreachable code.

test/libsolidity/syntaxTests/controlFlow/userDefinedOperators/unary_operator_struct.sol

@@ -0,0 +1,17 @@
+struct S { Z z; }
+struct Z { int x; }
+
+using {unsubS as -} for S;
+using {unsubZ as -} for Z;
+
+function unsubS(S memory) pure returns (S memory) {}
+function unsubZ(Z memory) pure returns (Z memory) { revert(); }
+
+contract C {
+    function f() public pure {
+        -S(-Z(1));
+        -S(Z(2)); // Unreachable
+    }
+}
+// ----
+// Warning 5740: (283-291): Unreachable code.