Write the given data to the stream. Returns the number of bytes written. Throws an exception on failure.

template<
    typename ConstBufferSequence>
std::size_t write_some(
    const ConstBufferSequence & buffers);

template<
    typename ConstBufferSequence>
std::size_t write_some(
    const ConstBufferSequence & buffers,
    asio::error_code & ec);