copy_string(BeginReading(cutEnd), EndReading(), BeginWriting(cutStart));
copy_string(this->BeginReading(cutEnd), this->EndReading(), BeginWriting(cutStart));
basic_nsAWritableString<CharT>::Cut( PRUint32 cutStart, PRUint32 cutLength )  {    PRUint32 myLength = Length();    cutLength = NS_MIN(cutLength, myLength-cutStart);    PRUint32 cutEnd = cutStart + cutLength;    if ( cutEnd < myLength )      copy_string(BeginReading(cutEnd), EndReading(), BeginWriting(cutStart));    SetLength(myLength-cutLength);  }