// C++ In A Nutshell example, page 36. Three version of divide.
// div returns an object that aggregates the quotient and the remainder.

#include <iostream>
#include <cstdlib>

// The type ldiv_t is a struct with a quotient and a remainder field.

void divide_1 (long num, long den, long& quo, long& rem){
  std::ldiv_t result = std::div(num, den);          // The struct is COPIED out of div
  quo = result.quot;                    
  rem = result.rem;
}

void divide_2 (long num, long den, long& quo, long& rem){
  const std::ldiv_t& result = std::div(num, den);  // The struct is NOT COPIED out of div.
  quo = result.quot;                               // Instead a const reference is established 
  rem = result.rem;                                // to the resulting struct.
                                                   // This most likely involves creating a temporary struct, however.
}

void divide_3 (long num, long den, long& quo, long& rem){
  std::ldiv_t& result = std::div(num, den);        // error: invalid initialization of non-const reference of type ldiv_t&
  quo = result.quot;                                       
  rem = result.rem;                       
} 

int main(){
  using namespace std;

  long  q, r;

  divide_1(107, 20, q, r);
  cout << q << " remainder " << r << endl;  // 5 remainder 7

  divide_2(107, 20, q, r);
  cout << q << " remainder " << r << endl;  // 5 remainder 7
}