rem: return dw_strcasecmp(s1, len1, s2, len2);
add: return dw_strasciicasecmp(s1, len1, s2, len2);
context: int DwStrcasecmp(const DwString& aStr, const char* aCstr){    assert(aCstr != 0);    const char* s1 = aStr.data();    size_t len1 = aStr.length();    const char* s2 = aCstr;    size_t len2 = (aCstr) ? strlen(aCstr) : 0;    return dw_strcasecmp(s1, len1, s2, len2);}