文件basic_socket.hpp中的lib boost asio 1.47.0出错

Question

i have an error in the following code when i tried to compile this:

void        Server::accept(void)
{
    Network::ptr connection = Network::initialize(this->my_acceptor.get_io_service());
    this->my_acceptor.async_accept(connection->socket(), bind(&Server::endCmd, this, *connection, placeholders::error));
}

void        Server::endCmd(Network connection, const boost::system::error_code& error)
{
    if (!error)
        {
            std::cout << "success!" << std::endl;
            connection.start();
            this->accept();
        }
}

VC++ 2010 tell me the following error :

Error   1   error C2248: 'boost::asio::basic_io_object<IoObjectService>::basic_io_object' : cannot access private member declared in class 'boost::asio::basic_io_object<IoObjectService>'

i know this error come to this line because when i comment it, the error disapear... After some research, it's probably with the socket's class when i call connection->getSocket() but this function returns a ref to an instance of socket :

tcp::socket& Network::socket(void)
{
    return (this->my_socket);
}

so i didn't find any solution on the web :(

Anyone have an idea plz ?

Answer 1

I had that problem too, and i spend a few hours to see what happened. My case was:

• Class A which contains a boost socket. The class A it was used as a member in class B.
• class B was a pointer and it was not copyable. Member A was declared as a reference in the B class.

Original code in the B class was:

std::bind(&A::a_member, a_instance)

The problem was fixed (and of course) by using the address of the a_instance:

std::bind(&A::a_member, &a_instance).

I did not notice that, and I took me a while to resolve this. I hope that it will be help others too.

Answer 2

Is async_accept something you wrote yourself? If so, make sure it takes a REFERENCE to socket, and not pass by value. The error you're getting is saying that you're trying to copy construct, and the copy constructor is declared private (this is a the C++ way of enforcing that the class doesn't support copying).