Create a new modifiable buffer that represents the given POD array.
template< typename PodType, std::size_t N> mutable_buffer buffer( std::array< PodType, N > & data, std::size_t max_size_in_bytes);
A mutable_buffer
value equivalent to:
mutable_buffer( data.data(), min(data.size() * sizeof(PodType), max_size_in_bytes));