Method write_float

include/fmt/format.h:2490–2497

template <typename OutputIt, typename DecimalFP, typename Char>
FMT_CONSTEXPR20 auto write_float(OutputIt out, const DecimalFP& f, const format_specs<Char>& specs, float_specs fspecs,
                                 locale_ref loc) -> OutputIt {
    if (is_constant_evaluated()) {
        return do_write_float<OutputIt, DecimalFP, Char, fallback_digit_grouping<Char>>(out, f, specs, fspecs, loc);
    } else {
        return do_write_float(out, f, specs, fspecs, loc);
    }
}

template <typename T> constexpr bool isnan(T value) {
    return !(value >= value); // std::isnan doesn't support __float128.