ConvertToLowerCase converter; converter.write(aCString.mStr, aCString.Length());
nsACString::const_iterator fromBegin, fromEnd; nsACString::iterator toBegin; aDest.SetLength(aSource.Length()); CopyToLowerCase converter(aDest.BeginWriting(toBegin)); copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), converter);
ToLowerCase( nsCString& aCString )  {    ConvertToLowerCase converter;    converter.write(aCString.mStr, aCString.Length());  }