#### buffered_read_stream::write_some

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);