c++ finally don't use std::function

runtime/Cpp/runtime/src/antlr4-common.h

@@ -34,7 +34,6 @@
 #include <exception>
 #include <bitset>
 #include <condition_variable>
-#include <functional>
 
 #ifndef USE_UTF8_INSTEAD_OF_CODECVT
   #include <codecvt>

runtime/Cpp/runtime/src/support/CPPUtils.cpp

@@ -202,12 +202,6 @@ namespace antlrcpp {
     return result;
   }
 
-  //----------------- FinallyAction ------------------------------------------------------------------------------------
-
-  FinalAction finally(std::function<void ()> f) {
-    return FinalAction(f);
-  }
-
   //----------------- SingleWriteMultipleRead --------------------------------------------------------------------------
 
   void SingleWriteMultipleReadLock::readLock() {

runtime/Cpp/runtime/src/support/CPPUtils.h

@@ -19,8 +19,9 @@ namespace antlrcpp {
   std::string indent(const std::string &s, const std::string &indentation, bool includingFirst = true);
 
   // Using RAII + a lambda to implement a "finally" replacement.
+  template <typename OnEnd>
   struct FinalAction {
-    FinalAction(std::function<void ()> f) : _cleanUp { f } {}
+    FinalAction(OnEnd f) : _cleanUp { std::move(f) } {}
     FinalAction(FinalAction &&other) :
 	_cleanUp(std::move(other._cleanUp)), _enabled(other._enabled) {
       other._enabled = false; // Don't trigger the lambda after ownership has moved.
@@ -29,11 +30,14 @@ namespace antlrcpp {
 
     void disable() { _enabled = false; }
   private:
-    std::function<void ()> _cleanUp;
+    OnEnd _cleanUp;
     bool _enabled {true};
   };
 
-  ANTLR4CPP_PUBLIC FinalAction finally(std::function<void ()> f);
+  template <typename OnEnd>
+  FinalAction<OnEnd> finally(OnEnd f) {
+    return FinalAction<OnEnd>(std::move(f));
+  }
 
   // Convenience functions to avoid lengthy dynamic_cast() != nullptr checks in many places.
   template <typename T1, typename T2>