debug websocket++ broadcast_server.cpp ('owner_less' is not a member of 'std')

Question 1

std::owner_less is a C++11 STL feature that allows you to put std::weak_ptr in associative containers like set and map. Ultimately, connection_hdl is a weak_ptr, and that is why it needs the custom comparison function.

WebSocket++ 0.3.x can be configured via preprocessor defines to use either C++03 + Boost or C++11. By default it uses C++03 + Boost. Boost weak_ptr works a little differently and does not need a custom comparison function. If you use a list, queue, or vector it is also unnecessary since those containers do not use the connection_hdl as keys.

Most of the examples in the 0.3.x manual and bundled with the library use C++11 because it is a lot more clean and concise. To compile and link those examples as is you will need a C++11 compiler and to use the appropriate C++11 compiler flags and WebSocket++ defines. Scons is the build system that I use to automate building & running all of the examples and unit tests. It is not necessary to build and run individual example programs. Any other build system should work fine, as will feeding compiler arguments ad hoc on the command line.

I've set up a page in the manual that describes the various options for enabling/disabling C++11 features. http://www.zaphoyd.com/websocketpp/manual/reference/cpp11-support. This manual page has a list of recommended compiler flags for the Operating systems and compilers I use most for testing.

For g++ 4.7 on Linux I would recommend: "-std=c++0x -D_WEBSOCKETPP_CPP11_STL_ -D_WEBSOCKETPP_NO_CPP11_REGEX_ -lboost_regex -lboost_system". This enables all C++11 features except the library (which is broken/buggy), and brings in the Boost version instead.

Question 2

After reading the documentation, I think you need to define BOOST_ROOT_CPP11 when building.

Similar to BOOST_ROOT but allows linking to a separate version of Boost compiled against a C++11 STL

I based this on the following header

#ifdef _WEBSOCKETPP_CPP11_MEMORY_
    using std::shared_ptr;
    using std::weak_ptr;
    using std::enable_shared_from_this;
    using std::static_pointer_cast;

    typedef std::unique_ptr<unsigned char[]> unique_ptr_uchar_array;
#else
    using boost::shared_ptr;
    using boost::weak_ptr;
    using boost::enable_shared_from_this;
    using boost::static_pointer_cast;

    typedef boost::scoped_array<unsigned char> unique_ptr_uchar_array;
#endif

Which should use std::weak_ptr instead of boost::weak_ptr

If you'd like to use an alternate container instead of std::set, modify the example similar to this pseudo code

         if (a.type == SUBSCRIBE) {
                boost::unique_lock<boost::mutex> lock(m_connection_lock);
                m_connections.push_back(a.hdl);
            } else if (a.type == UNSUBSCRIBE) {
                boost::unique_lock<boost::mutex> lock(m_connection_lock);
                m_connections.erase(std::remove(m_connections.begin(), m_connections.end(), a.hdl));
            } else if (a.type == MESSAGE) {
                boost::unique_lock<boost::mutex> lock(m_connection_lock);

                con_list::iterator it;
                for (it = m_connections.begin(); it != m_connections.end(); ++it) {
                    m_server.send(*it,a.msg);
                }
            } else {
                // undefined.
            }
        }
    }
private:
    typedef std::deque<connection_hdl> con_list;

Which will use std::deque instead of std::set. The ordering will not be used, but for what I can tell that isn't needed in this example.