#include <iostream>
#include <string>
using std::string;
using std::cout;
using std::endl;

template <typename T, typename U>
class holder
{
public:
    T item1;
    U item2;

    holder(const T& a, const U& b) : item1(a), item2(b) {}

    void print()
    {
        cout << "T: size= " << sizeof(T) << " value= " << item1 << endl;
        cout << "U: size= " << sizeof(U) << " value= " << item2 << endl;
        cout << endl;
    }
};

// specialization of the member function
template<>
void holder<int, int>::print()
{
    cout << "2 ints: " << item1 << " and " << item2 << endl;
    cout << endl;
}

// specialization of the class
template<>
class holder<double, double>
{
public:
    double d1;
    double d2;

    holder(const double& a, const double& b) : d1(a), d2(b) 
    {
        d1 *= 10;
        d2 *= 10;
    }

    void print()
    {
        cout << "2 doubles: " << d1 << " and " << d2 << endl;
        cout << endl;
    }
};

// partial specialization where the types are pointers
template <typename T, typename U>
class holder<T*, U*>
{
public:
    T* item1;
    U* item2;

    holder(const T& a, const U& b) 
    {
        item1 = new T(a);
        item2 = new U(b);
    }

    ~holder()
    {
        delete item1;
        delete item2; 
    }

    void print()
    {
        cout << "T* size= " << sizeof(item1) << " value= " << *item1 << endl;
        cout << "U* size= " << sizeof(item2) << " value= " << *item2 << endl;
        cout << endl;
    }
};


// partial specialization of the class, where first template parameter is char
template<typename U>
class holder<char, U>
{
public:
    char c1;
    U item2;

    holder(const char& a, const U& b) : c1(a), item2(b) 
    { }

    void print()
    {
        cout << c1 << c1 << c1 << " and val " << item2 << endl;
        cout << endl;
    }
};


int main(int argc, char** argv)
{
    cout << "holder<int, char> h(3, '2');" << endl;
    holder<int, char> h(3, '2');
    h.print();

    cout << "holder<int*, char*> h(3, '2');" << endl;
    holder<int*, char*> hpoint(3, '2');
    hpoint.print();

    cout << "holder<int, int> hi(3, 2);" << endl;
    holder<int, int> hi(3, 2);
    hi.print();

    cout << "holder<double, double> hd(3, 2);" << endl;
    holder<double, double> hd(3, 2);
    hd.print();

    cout << "holder<char, int> hp('3', 2);" << endl;
    holder<char, int> hp('3', 2);
    hp.print();

    return 0;
}