template specialization

ts.cpp

#include <iostream> /// std::cout
#include <cstdlib>  /// #EXIT_SUCCESS --> macro definition

template <typename T>
T sum (const T &t1, const T &t2) {
    return t1 + t2;
}

///******** template specializations of <T> sum ******************/// 

template <> /// template specialization of sum that takes a const int &, const int &
int sum (const int &s1, const int &s2) {
    return s1 + s2;
}

template <> /// template specialization of sum that takes a const double &, const double &
double sum (const double &s1, const double &s2) {
    return s1 + s2;
}

template <> /// template specialization of sum that takes a int * const &, int * const &
int *sum (int * const &sptr1, int * const &sptr2) {
    int *sp = new int (0);
    *sp = *sptr1 + *sptr2;
    return sp;
}

template <> /// template specialization of sum that takes a double * const &, double * const &
double *sum (double * const &sptr1, double * const &sptr2) {
    double *sp = new double (0.0);
    *sp = *sptr1 + *sptr2;
    return sp;
}

int main ()
{
    int n1 = 22, n2 = 24;
    int *ptr1 = &n1, *ptr2 = &n2;

    int *r = sum (ptr1, ptr2);

    std::cout << *r << std::endl;

    delete r; /// free the allocated mem from the template func

    return EXIT_SUCCESS; /// system independent return call
}