boost::text::v1::stream_safe_copy
// In header: <boost/text/stream_safe.hpp> template<code_point_range R, std::weakly_incrementable O> constexpr copy_result< std::ranges::borrowed_iterator_t< R >, O > stream_safe_copy(R && r, O out);
Writes sequence r
to out
, ensuring Stream-Safe Text Format.
See Also:
https://unicode.org/reports/tr15/#Stream_Safe_Text_Format