在聊天工作中，我想使用回调作为从特定客户端流到服务器的消息，该服务器稍后应该将该消息发送给其他客户端 .
这是该功能的代码：

void Server::waitForConnection(){

    Connection::pointer connect = Connection::create(accept.get_io_service());

    accept.async_accept(connect->getSocket(), boost::bind(&Server::acceptConnection, this, connect, boost::asio::placeholders::error));
}


void Server::acceptConnection(Connection::pointer connection, const boost::system::error_code& error){
    if (!error)
    {
        connections.push_back(connection);
        connection->readMsg(boost::bind(&Server::msgHandler,this, boost::placeholders::_1));
    }
    else
    {
        std::cout << "Server::acceptConnection error" << std::endl;
    }
    waitForConnection();

}

template<typename T> void Connection::readMsg(T msgHandler){
    const char delim = '\n';
    //boost::asio::async_read_until(soc, boost::asio::buffer(arr), delim);
    std::string tmp;
    do{
        boost::asio::read_until(soc, buf, delim);
        std::istream is(&buf);
        std::getline(is,tmp);
        msgHandler(tmp);
    } while (tmp != "leave");
}

编译后，我收到以下错误：

Server.obj：错误LNK2019：未解析的外部符号“public：void __thiscall Connection :: readMsg，class std :: allocator >>，class boost :: _ bi :: list2，struct boost :: arg <1 >>>>（ class boost :: _ bi :: bind_t，class std :: allocator >>，类boost :: _ bi :: list2，struct boost :: arg <1 >>>）“（?? $ readMsg @ V？$ bind_t @ XV ？$ @ MF1 @@ XVServer V'$ @的basic_string杜？$ @ char_traits @ d @@性病V'$ @分配器@ d @@ 2 STD @@@ _ MFI @提振@@ V'$ @列表2 V'$值@PAVServer @@@ 双@升压@@ U＆$ ARG @ $ @ 00 @@ 3双 @ 3 @@ _双@提升@@@连接@@ QAEXV？$ @ bind_t第十五？$ @ MF1 @@ XVServer V'$ basic_string的@杜？$ @ char_traits @ d @@性病V'$ @分配器@ d @@ 2 STD @@@ _ MFI @提振@@ V'$ @列表2 V'$ @值@@@ PAVServer _双@升压@@ U？$ arg @ $ 00 @ 3 @@ _ bi @ 3 @@ _ bi @ boost @@@ Z）在函数“private：void __thiscall Server :: acceptConnection”中引用（类boost :: shared_ptr，类boost :: system :: error_code const＆）“（？acceptConnection @ Server @@ AAEXV？$ shared_ptr @ VConnection @@@ boost @@ ABVerror_code @ system @ 3 @@ Z）

这是我用来尝试重新创建问题的最小，可编译的代码：

#include <iostream>
#include <boost/bind.hpp>
#include <cmath>

using namespace std;

class A;
class B;
class C;

class C{
public:
    template <typename T>void init(T t);
};

class B{
public:
template <typename T>void init(T t);
void what(string s);
};

void B::what(string s){
    cout << "in what " << s.c_str() << endl;
}

class A{
    B obj;
    int id;
public:
    void init();
    void func(string s);


};

void A::func(string s){

    cout << s.c_str() << " yes " <<id<< endl;
}
void A::init(){
    id = rand()%1024;
    obj.init(boost::bind(&A::func, this, boost::placeholders::_1));
}

template <typename T>void B::init(T t){
    //A a;
    //(a.*t)();
    C c;
    c.init(boost::bind(&B::what, this, boost::placeholders::_1));
    t("from B");
}

template <typename T>void C::init(T t){
    //A a;
    //(a.*t)();
    t("from C");
}

int main(){
    A a;
    a.init();
    a.func("main");
    system("pause");
}

然而，它无法达到其目的，这使我转向SO并询问实际上可能导致链接器错误的原因 .
完整代码：
Connection.cpp
Connection.h
Server.cpp
Server.h
main.cpp

c++ boost