PRUint32 oldLength = Length();
PRUint32 oldLength = this->Length();
basic_nsAWritableString<CharT>::do_ReplaceFromReadable( PRUint32 cutStart, PRUint32 cutLength, const basic_nsAReadableString<CharT>& aReplacement )  {    PRUint32 oldLength = Length();    cutStart = NS_MIN(cutStart, oldLength);    cutLength = NS_MIN(cutLength, oldLength-cutStart);    PRUint32 cutEnd = cutStart + cutLength;    PRUint32 replacementLength = aReplacement.Length();    PRUint32 replacementEnd = cutStart + replacementLength;    PRUint32 newLength = oldLength - cutLength + replacementLength;    if ( cutLength > replacementLength )      copy_string(BeginReading(cutEnd), EndReading(), BeginWriting(replacementEnd));    SetLength(newLength);    if ( cutLength < replacementLength )      copy_string_backward(BeginReading(cutEnd), BeginReading(oldLength), BeginWriting(replacementEnd));    copy_string(aReplacement.BeginReading(), aReplacement.EndReading(), BeginWriting(cutStart));  }