Determines the numeric value of a character as a decimal digit. If the
character is not a decimal digit according to funcGLib.ascii_isdigit,
-1 is returned.
Differs from funcGLib.unichar_digit_value because it takes a char, so
there's no worry about sign extension if characters are signed.
Determines the numeric value of a character as a decimal digit. If the character is not a decimal digit according to funcGLib.ascii_isdigit, -1 is returned.
Differs from funcGLib.unichar_digit_value because it takes a char, so there's no worry about sign extension if characters are signed.