Check if class has function with signature

Question

There are other answers on this site using SFINAE but with non C++11 code, and there are others using C++11 code like decltypes to make this process easier. However, I am no

Answer 1

There is help with macros:

#define DEFINE_METHOD_CHECKER(RETURN_TYPE, METHOD_NAME, PARAMETERS)     \
template                                                    \
struct Is ## METHOD_NAME ## MemberFunctionExists                        \
{                                                                       \
private:                                                                \
    typedef char True;                                                  \
    typedef char (&False)[2];                                           \
    template\
    struct Checker                                                      \
    {                                                                   \
        typedef True Type;                                              \
    };                                                                  \
    template                                                \
    static typename Checker::Type Tester(const U*);                  \
    static False Tester(...);                                           \
public:                                                                 \
    enum { value = (sizeof(Tester(static_cast(0))) == sizeof(True)) }; \
}

// IsMethodMemberFunctionExists::value
DEFINE_METHOD_CHECKER(int, Method, (bool));
// IsTestMemberFunctionExists::value
DEFINE_METHOD_CHECKER(int*, Test, (int&, char));

#include 

class Exists
{
public:
    int Method(bool);
    int* Test(int&, char);

};

class NotExists
{
};

int main()
{
    std::cout << IsMethodMemberFunctionExists::value << std::endl;
    std::cout << IsTestMemberFunctionExists::value << std::endl;

    std::cout << IsMethodMemberFunctionExists::value << std::endl;
    std::cout << IsTestMemberFunctionExists::value << std::endl;
}

So, in your case you need to define a few checkers - one checker for one type of Event:

// void recieve(const Event1&)
DEFINE_METHOD_CHECKER(void, recieve, (const Event1&));

// void recieve(const Event2&)
DEFINE_METHOD_CHECKER(void, recieve, (const Event2&));