From 1845101929264574318 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,cc1a555bbe9617a3 X-Google-Attributes: gidf78e5,public From: Valentin Bonnard Subject: Re: STL and SGI and strings Date: 1998/01/13 Message-ID: <34BB95E3.41C67EA6@pratique.fr>#1/1 X-Deja-AN: 315647363 References: <34B57837.41C6@pixar.com> <34B6580F.6A50@pratique.fr> <69e5d5$eki$1@news2.ispnews.com> X-Original-Date: Tue, 13 Jan 1998 17:27:15 +0100 Originator: austern@isolde.mti.sgi.com Organization: Ecole Normale Superieure, Paris, France X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBVAwUBNLvXiEy4NqrwXLNJAQHFMgH/R/v+MASvn5VxaEMFJ7Qa2Bj6dhppqFv0 pmdhVrPqgHL2nHDP4o1HOi6uvbDAuZ0EcZ8UzuZC7GaHj3fQtcHyCA== =MF+U Newsgroups: comp.std.c++ Brock wrote: > > Valentin Bonnard wrote in message <34B6580F.6A50@pratique.fr>... > <<< > > >The problem is that sharing is often impossible as: > >- operator[] has to return a charT& > > Does it have to return a charT& according to the standard? I read somewhere > (More Effective C++?) about an efficient way to determine whether operator[] > was used for read or write access by returning an object with an overloaded > operator=(charT), and an operator charT(). I even wrote a (hopeless) email > to my vendor (MS) complaining that their std::string implementation didn't > use this technique, as I had assumed it to be the standard way to do it. > > <<< >From 23.1.1 Sequences, Table 6: a[n] T&; const T& *(a.begin() + n) for constant a string is a sequence; also from 21.2 String classes/4: const_reference operator[](size_type pos) const; reference operator[](size_type pos); const_reference at(size_type n) const; reference at(size_type n); The standard can't be clearer. Don't complain when your implementor (especially MS) is right, it's so rare. You can implement your classes the way you want, BTW. -- Valentin Bonnard mailto:bonnardv@pratique.fr info about C++/a propos du C++: http://www.pratique.fr/~bonnardv/ --- [ comp.std.c++ is moderated. To submit articles: Try just posting with your newsreader. If that fails, use mailto:std-c++@ncar.ucar.edu comp.std.c++ FAQ: http://reality.sgi.com/austern/std-c++/faq.html Moderation policy: http://reality.sgi.com/austern/std-c++/policy.html Comments? mailto:std-c++-request@ncar.ucar.edu ]