c   boost::asio::buffer and structures
#include <boost/asio.hpp>

struct testStruct{
    int x;
    int y;
};

int main(){
    struct testStruct t;
    boost::asio::buffer b;
    b = boost::asio::buffer(t);
    return 0;
}

#include <boost/asio.hpp>

#include <vector>

struct testStruct{
    int x;
    int y;
};

int
main()
{
    struct testStruct t;
    t.x = 5;
    t.y = 7;

    std::vector<boost::asio::const_buffer> buffers;
    buffers.push_back( boost::asio::buffer(&t.x, sizeof(t.x) ) );
    buffers.push_back( boost::asio::buffer(&t.y, sizeof(t.y) ) );

    boost::asio::io_service io_service;
    boost::asio::ip::tcp::socket socket( io_service ); // note not connected!
    std::size_t length = boost::asio::write( socket, buffers );

    return 0;
}

class packet_writer
{
public:
    template <typename iter> void write(iter begin, iter end)
    {
        buffer_.insert(buffer_.end(), begin, end);
    }

    template <typename T> void write(T data)
    {
            int8_t* begin = reinterpret_cast<int8_t*>(&data);
        write(begin, begin + sizeof(data));
    }

    const std::vector<int8_t>& buffer() const
    {
        return buffer_;
    }

private:
    std::vector<int8_t> buffer_;
};