C++20 now considers equality to be commutable (A == B) === (B == A)

This means that the operator must be const so that swapping is allowed.

Algorithm/test/pageparser.cxx

@@ -50,7 +50,7 @@ struct ClusterData {
   {
   }
 
-  bool operator==(const ClusterData& rhs)
+  bool operator==(const ClusterData& rhs) const
   {
     return clusterid == rhs.clusterid && x == rhs.x && y == rhs.y && z == rhs.z && e == rhs.e;
   }

DataFormats/Headers/include/Headers/DataHeader.h

@@ -286,6 +286,8 @@ struct Descriptor {
   bool operator<(const Descriptor& other) const { return std::memcmp(this->str, other.str, N) < 0; }
   bool operator!=(const Descriptor& other) const { return not this->operator==(other); }
 
+  // Convesion operators for comparison with their implicitly convertible types
+  friend bool operator==(const Descriptor& lhs, ImplicitConversion rhs) { return static_cast<ImplicitConversion>(lhs) == rhs; }
   // explicitly forbid comparison with e.g. const char* strings
   // use: value == Descriptor<N>("DESC") for the appropriate
   // template instantiation instead

Framework/Core/test/test_ASoA.cxx

@@ -147,10 +147,10 @@ TEST_CASE("TestTableIteration")
 
   b = tests2.begin();
   REQUIRE(b != e);
-  REQUIRE((b + 1) == (b + 1));
-  REQUIRE((b + 7) != b);
-  REQUIRE((b + 7) != e);
-  REQUIRE((b + 8) == e);
+  REQUIRE(((b + 1) == (b + 1)));
+  REQUIRE(((b + 7) != b));
+  REQUIRE(((b + 7) != e));
+  REQUIRE(((b + 8) == e));
 
   for (auto& t : tests2) {
     REQUIRE(t.x() == value / 4);