Dealing with ctype.h integer overflow

[elitemx]

What is the proper way to deal with character values which when casted to an unsigned char fall between {INT_MAX + 1 ... UCHAR_MAX} where UCHAR_MAX is greater than INT_MAX.

int is_digit2(char c) {
    unsigned char uchar = c;
    if(uchar > INT_MAX)
        return MAYBE;
    return isdigit(uchar) ? YES : NO;
}