const PRUnichar* us = mString->get();
nsAString::const_iterator iter; mString->BeginReading(iter); const PRUnichar* us = iter.get();
StringUnicharInputStream::Read(PRUnichar* aBuf,                               PRUint32 aCount,                               PRUint32 *aReadCount){  if (mPos >= mLen) {    *aReadCount = 0;    return NS_OK;  }  const PRUnichar* us = mString->get();  NS_ASSERTION(mLen >= mPos, "unsigned madness");  PRUint32 amount = mLen - mPos;  if (amount > aCount) {    amount = aCount;  }  memcpy(aBuf, us + mPos, sizeof(PRUnichar) * amount);  mPos += amount;  *aReadCount = amount;  return NS_OK;}