Merge pull request #20453 from rogday:onnx_importer_fix

Split layer dispatch into functions in ONNXImporter

* split layer dispatch into functions

* fixes

* identation and comment fixes

* fix constness

modules/dnn/src/dnn_common.hpp

@@ -14,6 +14,7 @@ Mutex& getInitializationMutex();
 void initializeLayerFactory();
 
 namespace detail {
+#define CALL_MEMBER_FN(object, ptrToMemFn)  ((object).*(ptrToMemFn))
 
 struct NetImplBase
 {

modules/dnn/src/tensorflow/tf_importer.cpp

@@ -2869,7 +2869,7 @@ void TFImporter::parseNode(const tensorflow::NodeDef& layer)
         DispatchMap::const_iterator iter = dispatch.find(type);
         if (iter != dispatch.end())
         {
-            ((*this).*(iter->second))(net, layer, layerParams);
+            CALL_MEMBER_FN(*this, iter->second)(net, layer, layerParams);
         }
         else
         {