void SetLength(PRUint32 aLength) { Truncate(aLength);
void nsString::SetLength(PRInt32 aLength) { if(aLength>mLength) { EnsureCapacityFor(aLength); nsCRT::zero(mStr + mLength, (aLength - mLength) * sizeof(chartype));
  void SetLength(PRUint32 aLength) {     Truncate(aLength);  }