one can do some crazy stuff with c++11 and boost

fibonacci.cpp

#include <cstdlib>
#include <iostream>
#include <boost/coroutine/all.hpp>

using namespace boost::coroutines;
using namespace std;

int main()
{
    coroutine< int() > c(
        [&]( coroutine< void( int) > & c) {
            int first = 1, second = 1;
            for ( int i = 0; i < 10; ++i)
            {
                int third = first + second;
                first = second;
                second = third;
                c( third);
            }
        });

    for ( auto i : c) cout << i <<  " ";
    return 0;
}