|  | 
DynamicBuffer_v1: Get the size of the input sequence. DynamicBuffer_v2: Get the current size of the underlying memory.
std::size_t size() const;
          DynamicBuffer_v1 The current size of the
          input sequence. DynamicBuffer_v2: The
          current size of the underlying vector if less than max_size(). Otherwise returns max_size().