Deriving from p2p class (to attach custom/derived sessions & protocols)

derived_from_p2p.cpp

#include <bitcoin/network.hpp>

BC_USE_LIBBITCOIN_MAIN

// Inherit from P2P class.
class derived_from_p2p
  : public bc::network::p2p
{
public:
    typedef std::shared_ptr<derived_from_p2p> ptr;

    derived_from_p2p(const bc::network::settings settings)
      : bc::network::p2p(settings)
    {
        // Prints out correct number of seeds.
        bc::cout << "Number of seeds during constructor: " << std::endl;
        bc::cout << network_settings().seeds.size() << std::endl;
    }
};

int bc::main(int argc, char* argv[])
{
    bc::network::settings settings(bc::config::settings::testnet);
    settings.connect_batch_size = 10;
    settings.host_pool_capacity = 100;
    settings.seeds.clear();
    settings.seeds.push_back({"testnet2.libbitcoin.net",18333});
    settings.seeds.push_back({"testnet2.libbitcoin.net",18333});
    settings.seeds.push_back({"testnet3.libbitcoin.net",18333});

    // Promise which signals completion to main loop.
    std::promise<bc::code> complete;

    // Create derived P2P object (Not sure how to place this below Handlers, 
    // as these refer to derived P2P object).
    derived_from_p2p my_network(settings);

    // Problem: Seed list is empty after constructor.
    // ...seed session fails because no seeds returned.
    bc::cout << "Number of seeds after constructor: " << std::endl;
    bc::cout << my_network.network_settings().seeds.size() << std::endl;

    // Handlers
    // -------------------------------------------------------------------------

    const auto run_handler = [&my_network](const bc::code& ec)
    {
        // TODO
    };

    const auto start_handler = [&my_network, &complete, &run_handler](
        const bc::code& ec)
    {

        // (ignore error::peer_throttling)
        if (ec && ec != bc::error::peer_throttling)
        {
            complete.set_value(ec);
        }

        my_network.run(run_handler);
    };

    // Start P2P object.
    // -------------------------------------------------------------------------
  
    my_network.start(start_handler);
    bc::cout << complete.get_future().get().message() << std::endl;

    return 0;
}
// g++ -std=c++11 `pkg-config --cflags libbitcoin-network --libs libbitcoin-network` -o derived_from_network derived_from_network.cpp -DBOOST_LOG_DYN_LINK