Concurrent Hello in C++

concurrent_hello.cpp

#include <string>
#include <iostream>
#include <boost/fiber/unbounded_channel.hpp>

using namespace boost;
using namespace boost::fibers;

int main() {
    unbounded_channel<std::string> sayHello, sayWorld;

    fiber f1(spawn([&]() {
        optional<std::string> value;
        for (int i = 0; i < 1000; i++) {
            std::cout << "Hello ";
            sayWorld.put("Do it");
            sayHello.take(value);
        }
        sayWorld.put("Quit");
    }));

    fiber f2(spawn([&]() {
        while(true) {
            optional<std::string> reply;
            sayWorld.take(reply);
            if (*reply == "Quit") {
                break;
            }
            std::cout << " world!" << std::endl;
            sayHello.put("Do it");
        }
    }));

    waitfor_all(f1, f2);
}

// To compile: (tested under Ubuntu 12.04, gcc 4.7.2)
// Download boost_1_51_0
// Download http://ok73.ok.funpic.de/boost.fiber.zip
// Extract boost.fiber.zip to boost_1_51_0 (override existing boost.context, since boost.fiber is not part of boost yet)
// Compile boost:
// 1) To build bjam, run: ./bootstrap.sh
// 2) To compile boost, run: ./bjam link=static
// To compile this source run:
// g++ -std=c++11 -DBOOST_NO_RVALUE_REFERENCES \
//      -I "<path to>/boost_1_51_0"            \
//      concurrent_hello.cpp                   \
//      -o concurrent_hello                    \
//      -L "<path to>/boost_1_51_0/stage/lib"  \
//      -lboost_fibers -lboost_context -lboost_thread -lboost_chrono -lboost_system -lrt