получение ошибок LNK2005 и KNK1169 — включая один класс в другой

Я получаю эти ошибки:

Error   2   error LNK2005: "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl ToString(int)" (?ToString@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@H@Z) already defined in Sender.obj C:\CSE687\Project3_TT_1\Repository\Repository.obj

Error   3   error LNK2005: "private: static int Sender::count" (?count@Sender@@0HA) already defined in Sender.obj   C:\CSE687\Project3_TT_1\Repository\Repository.obj

Error   4   error LNK1169: one or more multiply defined symbols found   C:\CSE687\Project3_TT_1\Debug\Repository.exe

из этих трех частей кода:

#ifndef SEND_H
#define SEND_H
/////////////////////////////////////////////////////////////////
// Sender.cpp - Demonstration of concurrent socket connectors  //
// ver 2                                                       //
// Jim Fawcett, CSE687 - Object Oriented Design, Spring 2013   //
/////////////////////////////////////////////////////////////////
/*
* This Sender expects to write lines of text only.
* So message framing is done by lines.
*
* For HTTP like protocols the Sender should send lines for each
* header attribute and bytes in the body, if there is one,
* specified by a last header line something like:
*    content_length : 1024
* where 1024 is a stand-in for whatever you want your block
* size to be.
*
*/
/*
* Required files:
* - Sender.cpp, Sockets.h, Sockets.cpp,
*   Threads.h, Threads.cpp, Locks.h, Locks.cpp
*   BlockingQueue.h, BlockingQueue.cpp
*
* Maintanence History:
* ver 1.1 - 30 Mar 2013
* - changed Sendthread from terminating to default
* - minor changes to error handling
* ver 1.0 - 29 Mar 2013
* - first release
*/

#include "../sockets/Sockets.h"#include "../Threads/Threads.h"#include "../Threads/Locks.h"#include "../BlockingQueue/BlockingQueue.h"
#include <string>
#include <iostream>
#include <sstream>

///////////////////////////////////////////////////
// SendThread threadclass SendThread : public threadBase
{
public:
SendThread(Socket s, BlockingQueue<std::string>& q) : s_(s), q_(q) {}
std::string& status() { return status_; }
private:
void run()
{
status_ = "good";
doLog("send thread running");
std::string msg;
do
{
doLog("send thread enqing msg");
msg = q_.deQ();
if(!s_.writeLine(msg))
{
sout << "\n  bad status in sending thread";
status_ = "bad";
break;
}
} while(msg != "stop");
s_.disconnect();
}
std::string status_;
Socket s_;
BlockingQueue<std::string>& q_;
};std::string ToString(int i)
{
std::ostringstream conv;
conv << i;
return conv.str();
}class Sender
{
public:
Sender() {};
Sender(int numMsgs) : numMsgs_(numMsgs) { myCount = ++count; }
int id() { return myCount; }
void start(std::string ip, int port)
{
sout << locker << "\n Sender #" << id() << " started" << unlocker;
pSt = new SendThread(s_, q_);
pSt->start();
if(!s_.connect(ip, port))
{
sout << locker << "\n  couldn't connect to " << ip << ":" << port << "\n\n" << unlocker;
delete pSt;
return;
}
else
{
std::string logMsg = "\n  connected to " + ip + ":" + ToString(port);
doLog(logMsg.c_str());
}
doLog("starting Sender");
std::string msg;
for(int i=0; i<numMsgs_; ++i)
{
doLog("sending message");
msg = "sender#" + ToString(id()) + ": msg#" + ToString(i);
sout << locker << "\n  " << msg.c_str() << unlocker;
q_.enQ(msg);
::Sleep(10 * id());  // sleep time increases with each addition Sender
if(pSt->status() == "bad")
break;
}
q_.enQ("stop");
msg = "sender#" + ToString(id()) + ": stop";
sout << "\n  " + msg;
pSt->join();
delete pSt;
}
private:
Socket s_;
BlockingQueue<std::string> q_;
SendThread* pSt;
static int count;
int myCount;
int numMsgs_;
};

int Sender::count = 0;

///////////////////////////////////////////////////
// DemoThread is used to get two or more senders
// running concurrently from a single process, to
// make testing easier.

class DemoThread : public threadBase
{
public:
DemoThread(Sender sndr) : sndr_(sndr) {}
private:
void run()
{
sndr_.start("127.0.0.1", 8080);
}
Sender sndr_;
};

#endif

а также:

#ifndef REPOS_H
#define REPOS_H
/////////////////////////////////////////////////////////////////
// Recepository.h - Demonstration of repository action using a //
//  socket reciever with concurrent clients                    //
//                                                             //
// Thomas P. Taggart                                           //
// tptaggarsyr.edu                                             //
// CSE687, Object Oriented Design, Spring 2013                 //
/////////////////////////////////////////////////////////////////

/*
* Required files:
* - Reciever.h, Receiver.cpp, Sockets.h, Sockets.cpp,
*   Threads.h, Threads.cpp, Locks.h, Locks.cpp
*   BlockingQueue.h, BlockingQueue.cpp

*/
#include "../Sockets/Sockets.h"#include "../Threads/Threads.h"#include "../Threads/Locks.h"#include "../Receiver/Receiver.h"#include "../Sender/Sender.h"#include "../BlockingQueue/BlockingQueue.h"#include <string>class Repository
{

public:

Repository() {};
~Repository() {};

Sender* getSender();
Receiver* getReceiver();

private:

Sender* repoSender;
Receiver* repoReceiver;};#endif

а также:

/////////////////////////////////////////////////////////////////
// Recepository.cpp - Demonstration of repository action using //
//  a socket reciever with concurrent clients                  //
//                                                             //
// Thomas P. Taggart                                           //
// tptaggarsyr.edu                                             //
// CSE687, Object Oriented Design, Spring 2013                 //
/////////////////////////////////////////////////////////////////

/*
* Required files:
* - Reciever.h, Receiver.cpp, Sockets.h, Sockets.cpp,
*   Threads.h, Threads.cpp, Locks.h, Locks.cpp
*   BlockingQueue.h, BlockingQueue.cpp

*/#include "../Repository/Repository.h"#include <string>

using namespace std;Sender* Repository::getSender()
{
return repoSender;
}

Receiver* Repository::getReceiver()
{
return repoReceiver;
}int main()
{
int ret = 0;
try
{
Repository repos;
repos.getReceiver()->start(8080);
}
catch(std::exception& ex)
{
std::cout << "\n\n  " << ex.what();
ret = 1;
}
catch(...)
{
sout << "\n  something bad happened";
ret = 1;
}
sout << "\n\n";
return ret;
}

Я за всю жизнь не смог понять, как этого избежать. «внешнее» решение, похоже, не работает, а область заголовков #ifndef уже используется.

Любые советы высоко ценится.

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