If precision is specified, equivalent to to_chars(first, last, value, chars_format::hex, precision) where precision is the specified formatting precision; equivalent to to_chars(first, last, value, chars_format::hex) otherwise.

The same as a, except that it uses uppercase letters for digits above 9 and P to indicate the exponent.

Equivalent to to_chars(first, last, value, chars_format::scientific, precision) where precision is the specified formatting precision, or 6 if precision is not specified.

The same as e, except that it uses E to indicate exponent.

Equivalent to to_chars(first, last, value, chars_format::fixed, precision) where precision is the specified formatting precision, or 6 if precision is not specified.

Equivalent to to_chars(first, last, value, chars_format::general, precision) where precision is the specified formatting precision, or 6 if precision is not specified.

The same as g, except that it uses E to indicate exponent.

If precision is specified, equivalent to to_chars(first, last, value, chars_format::general, precision) where precision is the specified formatting precision; equivalent to to_chars(first, last, value) otherwise.