Fix compatibility with protobuf 22 (#405)

Signed-off-by: Silvio Traversaro <silvio@traversaro.it>

Author: traversaro

CMakeLists.txt

@@ -38,9 +38,7 @@ message(STATUS "\n\n-- ====== Finding Dependencies ======")
 
 #--------------------------------------
 # Find Protobuf
-set(REQ_PROTOBUF_VER 3)
 ign_find_package(IgnProtobuf
-                 VERSION ${REQ_PROTOBUF_VER}
                  REQUIRED
                  PRETTY Protobuf)
 

include/gz/transport/RepHandler.hh

@@ -26,7 +26,7 @@
 #pragma warning(pop)
 #endif
 
-#if GOOGLE_PROTOBUF_VERSION > 2999999
+#if GOOGLE_PROTOBUF_VERSION > 2999999 && GOOGLE_PROTOBUF_VERSION < 4022000
 #include <google/protobuf/stubs/casts.h>
 #endif
 
@@ -140,7 +140,11 @@ namespace ignition
           return false;
         }
 
-#if GOOGLE_PROTOBUF_VERSION > 2999999
+#if GOOGLE_PROTOBUF_VERSION >= 4022000
+        auto msgReq =
+          google::protobuf::internal::DownCast<const Req*>(&_msgReq);
+        auto msgRep = google::protobuf::internal::DownCast<Rep*>(&_msgRep);
+#elif GOOGLE_PROTOBUF_VERSION > 2999999
         auto msgReq = google::protobuf::down_cast<const Req*>(&_msgReq);
         auto msgRep = google::protobuf::down_cast<Rep*>(&_msgRep);
 #else

include/gz/transport/SubscriptionHandler.hh

@@ -28,7 +28,7 @@
 
 #include <google/protobuf/stubs/common.h>
 
-#if GOOGLE_PROTOBUF_VERSION >= 3000000
+#if GOOGLE_PROTOBUF_VERSION >= 3000000 && GOOGLE_PROTOBUF_VERSION < 4022000
 #include <google/protobuf/stubs/casts.h>
 #endif
 
@@ -211,7 +211,9 @@ namespace ignition
         if (!this->UpdateThrottling())
           return true;
 
-#if GOOGLE_PROTOBUF_VERSION >= 3000000
+#if GOOGLE_PROTOBUF_VERSION >= 4022000
+        auto msgPtr = google::protobuf::internal::DownCast<const T*>(&_msg);
+#elif GOOGLE_PROTOBUF_VERSION >= 3000000
         auto msgPtr = google::protobuf::down_cast<const T*>(&_msg);
 #else
         auto msgPtr = google::protobuf::internal::down_cast<const T*>(&_msg);