gistfile1.cpp

for ( auto it = ConnectedSockets.cbegin(); it != ConnectedSockets.cend(); ++it )
        {
            if ( send( it->second, buffer, wrapper.ByteSize() + 4, 0 ) < 0 )
            {
                fprintf( stderr, "Failed to send packet to '%s' (error = %s)\n", it->first.c_str(),
                         strerror( errno ) );

                it = ConnectedSockets.erase( it );
            }
        }