user-defined literals example

#include <stdio.h>
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
#include <iterator>
#include <cstdlib>
#include <cstring>

using namespace std;

struct cmplx
{
    double i, j;
    cmplx(string str)
    {
        char * pch;
        str.pop_back();
        pch = strtok (const_cast<char*>(str.c_str())," +");
        i = atof(pch);
        pch = strtok (NULL, " +");
        j = atof(pch);
    }
    
    friend ostream& operator<< (ostream& out, const cmplx& c)
    {
        out << c.i << " + " << c.j << "j";
        return out;
    }
};

cmplx operator "" _c(const char * str, size_t len)
{
    cmplx ret(str);
    return ret;
}

int main()
{
    printf("Hello World\n");
    cmplx com = "12 + 14j"_c;
    cout << com << endl;
    cmplx com2 = "12.5 + 21.4j"_c;
    cout << com2 << endl;
    return 0;
}