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Re: datatype for bit flags

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Message-ID <4E743FAD.3203@mindspring.com> (permalink)
Date Sat, 17 Sep 2011 02:35:25 -0400
From pete <pfiland@mindspring.com>
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Subject Re: datatype for bit flags
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Cross-posted to 2 groups.

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Keith Thompson wrote:
> 
> pete <pfiland@mindspring.com> 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

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Thread

datatype for bit flags Gr <g@g.com> - 2011-09-15 12:37 +0530
  Re: datatype for bit flags jacob navia <jacob@spamsink.net> - 2011-09-15 09:26 +0200
    Re: datatype for bit flags Gr <g@g.com> - 2011-09-15 13:33 +0530
      Re: datatype for bit flags jacob navia <jacob@spamsink.net> - 2011-09-15 10:12 +0200
  Re: datatype for bit flags Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-15 01:06 -0700
  Re: datatype for bit flags "BartC" <bc@freeuk.com> - 2011-09-15 10:56 +0100
    Re: datatype for bit flags Gr <g@g.com> - 2011-09-15 17:24 +0530
  Re: datatype for bit flags Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-09-16 01:16 +0300
    Re: datatype for bit flags Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-16 04:59 -0700
      Re: datatype for bit flags Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-09-16 20:46 +0000
        Re: datatype for bit flags pete <pfiland@mindspring.com> - 2011-09-16 18:00 -0400
        Re: datatype for bit flags Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-09-18 05:00 -0700
          Re: datatype for bit flags Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-09-18 13:36 +0000
      Re: datatype for bit flags "Tony" <nospamme@ever.net> - 2011-09-16 16:47 -0500
        Re: datatype for bit flags pete <pfiland@mindspring.com> - 2011-09-16 18:35 -0400
          Re: datatype for bit flags Keith Thompson <kst-u@mib.org> - 2011-09-16 16:25 -0700
            Re: datatype for bit flags pete <pfiland@mindspring.com> - 2011-09-17 02:35 -0400
              Re: datatype for bit flags Keith Thompson <kst-u@mib.org> - 2011-09-17 14:42 -0700
          Re: datatype for bit flags "Tony" <nospamme@ever.net> - 2011-09-16 19:27 -0500
  Re: datatype for bit flags hanukas <jukka@liimatta.org> - 2011-09-23 03:56 -0700

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