#include "boost/variant.hpp"
#include <iostream>
#include "PerfTimer.h"

using namespace std;

class my_visitor : public boost::static_visitor<int>
{
public:
   int operator()(int i) const
   {
       return i;
   }
     int operator()(const std::string & str) const
   {
       return static_cast<int>( str.length() );
   }
};

struct Base
{
   int i;
   std::string s;

   virtual int len() = 0;   };

struct Derived1 : public Base
{
   virtual int len()
   {
       return i;
   }
};

struct Derived2 : public Base
{
   virtual int len()
   {
       return static_cast<int>(s.length() );
   }
};

int main()
{
   boost::variant< int, std::string > u("hello world");
   int sum = 0;
   int N = 1000000;
   Derived2  der;
   der.i = 10;
   der.s = "hello world";
   Base*    b = &der;
   PerfTimer t;

   t.start();
   for( int i=0; i < N; ++i )
       sum += boost::apply_visitor( my_visitor(), u );
   t.stop();


   std::cout << sum<<std::endl;

   t.start();
   for( int i=0; i < N; ++i )
       sum += b->len();         
   t.stop();


   std::cout << sum<<std::endl;
   sum=0;
   u = 5;
	
   t.start();
   for( int i=0; i < N; ++i )
       sum += boost::apply_visitor( my_visitor(), u );
   t.stop();
   std::cout << sum<<std::endl;
}