win7下。C++实现多人聊天室上

#define _WINSOCK_DEPRECATED_NO_WARNINGS 
#define  _CRT_SECURE_NO_WARNINGS
#ifndef _H_H_
#define _H_H_
#include <thread>
#include <iostream>
#include <string>
#include <WinSock2.h>
#include <stdlib.h>
#pragma  comment(lib,"ws2_32.lib")
using namespace std;
static struct MyStruct
{
  SOCKET sock;
  int empt;
}soc[4];
class Server
{ 

public:

  Server();
  ~Server();
  static void talk(int id);
private:
  SOCKET s;

};
#endif // _H_H_

#include "h.h"
Server::Server()
{
  WSADATA wsadata;
  WORD v = MAKEWORD(2, 2);
  if (::WSAStartup(v, &wsadata) < 0)
    exit(0);
  s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  sockaddr_in sin;
  sin.sin_family = AF_INET;
  sin.sin_port = htons(4567);
  sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
  if (::bind(s, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
    return;
  if (::listen(s, 5) == SOCKET_ERROR)
    return;
cout << "The server has been started " << endl;
  while (1)
  {
    
    int i;
    for ( i = 0; i < 4; i++)
    {
      if (soc[i].empt==0)
      {
        soc[i].empt = 1;
        break;
      }
    }
    sockaddr_in re;
    int n = sizeof(re);
    soc[i].sock = ::accept(s, (SOCKADDR*)&re, &n);
    if (soc[i].sock==INVALID_SOCKET)
    {
      return;
    }
    std::thread t(talk, i);
    t.detach();
  }
  closesocket(s);
}

Server::~Server()
{

  ::WSACleanup();
}

void Server::talk(int id)
{
  char hello[] = "Welcome";
  ::send(soc[id].sock, hello, 7, 0);
  while (true)
  {
    char buff[255];
    int nR = ::recv(soc[id].sock, buff, 256, 0);
    if (nR>0)
    {
      buff[nR] = '\0';
      char buf[300];
           _itoa(id, buf, 10);
       strcat(buf, buff);
      for (int i = 0; i < 4; i++)
      {

        if (soc[i].empt)
        {

          ::send(soc[i].sock, buf, strlen(buf), 0);
        }
      }
    }
    else
    {     
      closesocket(soc[id].sock);
      soc[id].empt = 0;
      return;
    }
  }
}

#include "h.h"

int main()
{
  Server server;
  return 0;
}

想法是接收数据。收到以后。把信息发给所有连接在线的人。