From -6137596375456509496 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: f78e5,290ced9644daa112 X-Google-Attributes: gidf78e5,public From: Brian White Subject: Re: Types with Bit-Sizes Date: 1998/03/17 Message-ID: <350DA497.2B484CB4@verisim.com>#1/1 X-Deja-AN: 334712816 Content-Transfer-Encoding: 7bit References: <35084BDC.4108978E@verisim.com> X-Original-Date: Mon, 16 Mar 1998 17:15:51 -0500 Content-Type: text/plain; charset=us-ascii X-Complaints-To: usenet@news20.bellglobal.com X-Trace: news21.bellglobal.com 890086833 3595 (None) 207.236.110.153 Organization: Verisim, Inc. http://www.verisim.com/ X-Auth: PGPMoose V1.1 PGP comp.std.c++ iQBFAgUANQ2/YOEDnX0m9pzZAQFdJwF9FwumfD4PnqQopMobvBuDVFs74POkJdyn ikxaJsb9YSZkFTjepTfmCvseSc6nbPBb =7nYs Mime-Version: 1.0 Newsgroups: comp.std.c++ > > Is there anything in the the ANSI C++ spec that provides for datatypes of > > known bit sizes? > > This get's mentioned quite often around C++, but the reality is that > passing structs between machines is a really bad idea. > > The best way to achieve compatibility is to override your objects with > serialize methods (or use streams) to put and get the data. Unfortunately, this doesn't help unless you convert everything down to the byte level. Writing out a sequence of ints will still break if both machines don't have the same sizeof(int). If I have to do everything at the byte-level, what's the point of having any other types in the first place? > Relying on bit/byte size, or even the fact that structures will actually > stay the same size, with members in the same positions between revs of > compilers/code bases is not realistic. And therein lies another problem. Structures get written out to disk or passed over a network so often that it would be very useful to have some way of mapping these two in a way that is guaranteed not to change. Brian ( bcwhite@verisim.com ) ------------------------------------------------------------------------------- Stress: The condition caused by resisiting the desire to choke the life out of some idiot who desperately deserves it. --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://reality.sgi.com/austern_mti/std-c++/faq.html ]