Function parse_precision

extlibs/fmt/include/fmt/format.h:2473–2492

template <typename Char, typename Handler>
FMT_CONSTEXPR const Char* parse_precision(const Char* begin, const Char* end,
                                          Handler&& handler) {
  ++begin;
  auto c = begin != end ? *begin : Char();
  if ('0' <= c && c <= '9') {
    handler.on_precision(parse_nonnegative_int(begin, end, handler));
  } else if (c == '{') {
    ++begin;
    if (begin != end) {
      begin =
          parse_arg_id(begin, end, precision_adapter<Handler, Char>(handler));
    }
    if (begin == end || *begin++ != '}')
      return handler.on_error("invalid format string"), begin;
  } else {
    return handler.on_error("missing precision specifier"), begin;
  }
  handler.end_precision();
  return begin;
}

// Parses standard format specifiers and sends notifications about parsed
// components to handler.