Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!news.glorb.com!npeer02.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!border3.nntp.dca.giganews.com!Xl.tags.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!nntp.earthlink.com!news.earthlink.com.POSTED!not-for-mail NNTP-Posting-Date: Sat, 17 Sep 2011 01:35:23 -0500 Message-ID: <4E743FAD.3203@mindspring.com> Date: Sat, 17 Sep 2011 02:35:25 -0400 From: pete Reply-To: pfiland@mindspring.com Organization: PF X-Mailer: Mozilla 3.04Gold (WinNT; I) MIME-Version: 1.0 Newsgroups: comp.lang.c,comp.lang.c++ Subject: Re: datatype for bit flags References: <87k4994fkd.fsf@bazspaz.fatphil.org> <930e767b-26f0-4123-836d-64dac1f47cfb@d2g2000vbk.googlegroups.com> <4E73CF44.619F@mindspring.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 32 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 4.154.216.217 X-Trace: sv3-7n2Wq7ctcm1yJxMwpuhNQUxQLSjccJxf7V8mAF32oQAc6KDxJbeiXYJ2CSxMXCcFPfj5RuPfIS6nhni!3z+3mgYNvl5L1EI8ls0vGuIUwc0ZOQINiAFRA6QkPt0HAd71Pchao7VxUgVY/4Z+B747gLePkWLY!I4ltG5D6yPE= X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 X-Original-Bytes: 2240 Xref: x330-a1.tempe.blueboxinc.net comp.lang.c:10384 comp.lang.c++:10215 Keith Thompson wrote: > > pete writes: > > Tony wrote: > >> > >> Malcolm McLean wrote: > >> > >> > You should use int for an > >> > integer unless there is a > >> > clear reason for using another type. Though > >> > each instance will only save a few cycles, > >> > if you systematically use > >> > int the speed increment may be worth having. > >> > >> Did you mean that just in the context of the OP/this thread, or in > >> general? > > > > I only use data types which are smaller than int, > > when there is a special reason. > > > > It's possible that small types may be aligned on int boundaries, > > meaning that there may be unusable bytes in between them. > > No, it's not. In an array of char, or an array of short, the elements > must be contiguous; unlike structs arrays have no padding. > This is necessary > to make array indexing and pointer arithmetic work. It's possible that small types may exist outside of an array. -- pete