max_code_points
The maximum number of code points needed for a given encoding object. This can be used to create a suitably-sized automatic storage duration buffer, e.g.
using code_point = ztd::text::code_point_t<ztd::text::utf8>;
constexpr std::size_t max_output_size = ztd::text::max_code_points_v<ztd::text::utf8>;
std::array<code_point, max_output_size> my_cxx_buffer;
code_point my_c_buffer[max_output_size];