main.cpp
#include <boost/thread.hpp>
#include <boost/bind.hpp>
#include <stdlib.h>
#include <iostream>
#include "server.hpp"

int main(int argc, char* argv[]) {
	boost::thread listenThread(boost::bind(localLoop, 90));
	listenThread.join();
	while (1) {
		if ( std::cin.get() ) {
			break;
		}
		Sleep(1000);
	}
	return 0;
}

server.hpp
extern void localLoop(int port);

server.cpp
#include <boost/thread.hpp>
#include <boost/bind.hpp>
#include "asio.hpp"
#include <fstream>
#include <stdlib.h>
#include <string>
#include <iostream>

void loopLocal(int port) {
	while ( true ) {
		std::cout << "I'M SPINNING!" << std::endl;
	}
}