Function _parseUInt

Fleece/Support/NumConversion.cc:25–46

subroutine that parses only digits

    // subroutine that parses only digits
    static bool _parseUInt(const char *str NONNULL, uint64_t &result, bool allowTrailing) {
        uint64_t n = 0;
        if (!isdigit(*str))
            return false;
        while (isdigit(*str)) {
            int digit = (*str++ - '0');
            if (_usuallyFalse(n > UINT64_MAX / 10))
                return false;
            n *= 10;
            if (_usuallyFalse(n > UINT64_MAX - digit))
                return false;
            n += digit;
        }
        if (!allowTrailing) {
            while (isspace(*str))
                ++str;
            if (_usuallyFalse(*str != '\0'))
                return false;
        }
        result = n;
        return true;
    }

    // Unsigned version:
    bool ParseInteger(const char *str NONNULL, uint64_t &result, bool allowTrailing) {