Как на c++ сделать watermark в виде перебора символов аля брут?

const auto charset = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";
static wchar_t buildDate[256];
swprintf(buildDate, L"pCode | %hs %hs", __DATE__, __TIME__);
static int len = std::wstring(buildDate).length();
static bool bSleep = false;
static int delayTime;
static int pos = 0;

if (pos > -1) {
	for (int i = 0; i < len; ++i) {
		if (i >= pos) buildDate[i] = charset[rand() % strlen(charset) - 1];
	}
}

Visuals::RenderText(buildDate, 10, 10, Color(255, 255, 255, 255), g_Storage.fonts.outline);

if (!bSleep) {
	pos++;
	bSleep = true;
	delayTime = GetTickCount() + 50;
	if (pos == len) {
		pos = -1;
		delayTime += 500;
	}
}
else if (delayTime < GetTickCount()) {
	bSleep = false;
}