C++ template overload call - c++

Question

I am trying to implement an execution pattern which takes any function and executes it with its own conditions/preparations. Regardless of this being a useful thing to do, it just doesn't work. It seems i can't access the template overload of the "Execute"-function (called in "main").
Specifically: Why can't i call the overloaded template function of Execute?
This is the full program:
#include "stdafx.h"
#include <functional>
class TransparentFunctionWrapper
{
public:
virtual void Execute(std::function<void()> executeFunction) = 0;
template<class C>
C Execute(std::function<C(void)> executeFunction) // template-overload of the abstract function which will implicitly call it
{
C ret;
Execute( // calls the abstract function with a lambda function as parameter
[ret, executeFunction](void) -> C // lambda declaraction
{ //
ret = executeFunction; // lambda body
}); //
return ret;
}
};
class ExampleExecutor : public TransparentFunctionWrapper
{
public:
virtual void Execute(std::function<void()> executeFunction)
{
printf("executed before.");
executeFunction();
printf("executed after.");
}
};
void DoStuff() {}
int ReturnStuff() { return -5; }
int main()
{
ExampleExecutor executor;
executor.Execute(DoStuff);
int i = executor.Execute<int>(ReturnStuff); // Why does this not work? ERROR: "type name is not allowed"
getchar();
return 0;
}
Note: Visual Studio marks
Execute<int>(ReturnStuff) // "int" is marked as Error: type name is not allowed
The compilation puts out the error
"type 'int' unexpected"
Thanks to everyone willing to help!

Answer 1

ExampleExecutor::Execute is not overriding TransparentFunctionWrapper::Execute, and it is hiding it in the executor.Execute<int> call.
You must explicitly call TransparentFunctionWrapper::Execute, as it is hidden by ExampleExecutor::Execute. Here's a possible way of doing that:
int i = executor.TransparentFunctionWrapper::Execute<int>(ReturnStuff);
live example on coliru