dataflow_cpp: fixed gcc issue

dataflow_cpp/include/embb/dataflow/internal/constant_source.h

@@ -71,7 +71,7 @@ class ConstantSource
 
   template <typename T>
   void operator >> (T & target) {
-    GetOutput<0>() >> target.GetInput<0>();
+    GetOutput<0>() >> target.template GetInput<0>();
   }
 };
 

dataflow_cpp/include/embb/dataflow/internal/process.h

@@ -100,7 +100,7 @@ class Process< Slices, Serial, Inputs<Slices, I1, I2, I3, I4, I5>,
 
   template <typename T>
   void operator >> (T & target) {
-    GetOutput<0>() >> target.GetInput<0>();
+    GetOutput<0>() >> target.template GetInput<0>();
   }
 
   virtual void OnClock(int clock) {

dataflow_cpp/include/embb/dataflow/internal/select.h

@@ -101,7 +101,7 @@ class Select
 
   template <typename T>
   void operator >> (T & target) {
-    GetOutput<0>() >> target.GetInput<0>();
+    GetOutput<0>() >> target.template GetInput<0>();
   }
 
   virtual void OnClock(int clock) {

dataflow_cpp/include/embb/dataflow/internal/source.h

@@ -83,7 +83,7 @@ class Source< Slices, Outputs<Slices, O1, O2, O3, O4, O5> >
 
   template <typename T>
   void operator >> (T & target) {
-    GetOutput<0>() >> target.GetInput<0>();
+    GetOutput<0>() >> target.template GetInput<0>();
   }
 
  private:

dataflow_cpp/include/embb/dataflow/internal/switch.h

@@ -98,7 +98,7 @@ class Switch
 
   template <typename T>
   void operator >> (T & target) {
-    GetOutput<0>() >> target.GetInput<0>();
+    GetOutput<0>() >> target.template GetInput<0>();
   }
 
   virtual void OnClock(int clock) {