repos/Callback_34/Callback_34/Callback_34.cpp

#include <typeinfo>
#include <typeindex>
#include <unordered_map>
#include <iostream>

using namespace std;

template <typename R>
class MultiFuncObject {
    unordered_map<type_index, void (*)()> m_funcs;
public:

    MultiFuncObject<R> operator +=(R(*f)()) {
        m_funcs[typeid(R())] = (void (*)()) f;
        return *this;
    }

    template <typename A1>
    MultiFuncObject<R> operator +=(R(*f)(A1)) {
        m_funcs[typeid(R(A1))] = (void (*)()) f;
        return *this;
    }

    template <typename A1, typename A2>
    MultiFuncObject<R> operator +=(R(*f)(A1, A2)) {
        m_funcs[typeid(R(A1, A2))] = (void (*)()) f;
        return *this;
    }

    template <typename A1, typename A2, typename A3>
    MultiFuncObject<R> operator +=(R(*f)(A1, A2, A3)) {
        m_funcs[typeid(R(A1, A2, A3))] = (void (*)()) f;
        return *this;
    }

    R operator()() const
    {
        unordered_map<type_index, void (*)()>::const_iterator it = m_funcs.find(typeid(R()));
        if (it != m_funcs.end()) {
            R(*f)() = (R(*)())(it->second);
            (*f)();
        }
    }

    template <typename A1>
    R operator()(A1 a1) const
    {
        unordered_map<type_index, void (*)()>::const_iterator it = m_funcs.find(typeid(R(A1)));
        if (it != m_funcs.end()) {
            R(*f)(A1) = (R(*)(A1))(it->second);
            (*f)(a1);
        }
    }

    template <typename A1, typename A2>
    R operator()(A1 a1, A2 a2) const
    {
        unordered_map<type_index, void (*)()>::const_iterator it = m_funcs.find(typeid(R(A1, A2)));
        if (it != m_funcs.end()) {
            R(*f)(A1, A2) = (R(*)(A1, A2))(it->second);
            (*f)(a1, a2);
        }
    }

    template <typename A1, typename A2, typename A3>
    R operator()(A1 a1, A2 a2, A3 a3) const
    {
        unordered_map<type_index, void (*)()>::const_iterator it = m_funcs.find(typeid(R(A1, A2, A3)));
        if (it != m_funcs.end()) {
            R(*f)(A1, A2, A3) = (R(*)(A1, A2, A3))(it->second);
            (*f)(a1, a2, a3);
        }
    }
};

struct myData {
    int myAge = 55;
    const char* pchar = "myData struct";
    enum en_sex { MALE, FEMALE, DIVERS } sex = MALE;
};

struct myOtherData : myData {
    int myOtherAge = 35;
};


void _1() {
    cout << "_1" << endl;
}

void _2(myData* a) {
    cout << "_2" << " " << a->pchar << endl;
}

void _3(myData* a, myOtherData* b) {
    b->myOtherAge = 25;
    cout << "_3" << " " << b->myOtherAge << endl;
}

void _4(myData* a, myOtherData* b, int c) {
    b->myOtherAge = c;
    cout << "_3" << " " << b->myOtherAge << endl;
}



int main() {

    myData mydata = { 55, "myData struct", myData::MALE };
    myOtherData myotherdata;

    MultiFuncObject<void> funcs;
    funcs += &_1;
    funcs += &_2;
    funcs += &_3;
    funcs += &_4;

    funcs();
    funcs(&mydata);
    funcs(&mydata, &myotherdata); 
    funcs(&mydata, &myotherdata, 15);

    return 0;
}