Function grow

demo_example/asio/asio/buffer.hpp:1757–1766

@b DynamicBuffer_v2: Grow the underlying memory by the specified number of bytes. * Resizes the string to accommodate an additional @c n bytes at the end. * * @throws std::length_error If size() + n > max_size() . */

   * @throws std::length_error If <tt>size() + n > max_size()</tt>.
   */
  void grow(std::size_t n)
  {
    if (size() > max_size() || max_size() - size() < n)
    {
      std::length_error ex("dynamic_string_buffer too long");
      asio::detail::throw_exception(ex);
    }

    string_.resize(size() + n);
  }

  /// @b DynamicBuffer_v2: Shrink the underlying memory by the specified number
  /// of bytes.