Using variable-length argument lists : variable length argument lists « Development « C++ Tutorial

1. C++ Tutorial
2. Development
3. variable length argument lists

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

#include <iomanip>
using std::setw;
using std::setprecision;
using std::setiosflags;
using std::fixed;

#include <cstdarg>
using std::va_list;

double f( int, ... );

int main()
{
   double double1 = 3.5;
   double double2 = 2.5;
   double double3 = 1.7;
   double double4 = 1.2;

   cout << f( 2, double1, double2 ) << endl
        << f( 3, double1, double2, double3 ) << endl
        << f( 4, double1, double2, double3, double4 ) << endl
        << endl;
   return 0;
}
double f( int count, ... )
{
   double total = 0;
   va_list list;  // for storing information needed by va_start

   va_start( list, count );

   for ( int i = 1; i <= count; i++ )
      total += va_arg( list, double );

   va_end( list );
   return total;
}

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