Ustring format_int(T t, uint64_t flags, int prec) {
static constexpr auto float_flags = Format::digits | Format::exp | Format::fixed | Format::general | Format::stripz;
static constexpr auto int_flags = Format::binary | Format::decimal | Format::hex | Format::roman;
static constexpr auto sign_flags = Format::sign | Format::signz;
if ((flags & float_flags) && ! (flags & int_flags))
return format_float(t, flags, prec);
if (ibits(flags & int_flags) > 1 || ibits(flags & sign_flags) > 1)
throw std::invalid_argument("Inconsistent integer formatting flags");
char sign = 0;
if (t > static_cast<T>(0)) {
if (flags & (Format::sign | Format::signz))
sign = '+';
} else if (t == static_cast<T>(0)) {
if (flags & Format::sign)
sign = '+';
} else {
t = RS_Detail::SimpleAbs<T>()(t);
sign = '-';
}
Ustring s;
if (flags & Format::binary)
s = format_radix(t, 2, prec);
else if (flags & Format::roman)
s = roman(unsigned(t));
else if (flags & Format::hex)
s = format_radix(t, 16, prec);
else
s = format_radix(t, 10, prec);
if (sign)
s.insert(s.begin(), sign);
return s;
}
Ustring format_radix(T t, int base, int prec) {
// Argument will never be negative
Ustring s;
auto b = static_cast<T>(base);
prec = std::max(prec, 1);
while (t > 0 || int(s.size()) < prec) {
auto d = t % b;
s += char(d + (d <= 9 ? '0' : 'a' - 10));
t /= b;
}
std::reverse(s.begin(), s.end());
return s;
}
