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Groups > comp.lang.c++ > #11494

Re: Special Data Type Declaration and Usage

From Brian Drummond <brian@shapes.demon.co.uk>
Newsgroups comp.lang.c++
Subject Re: Special Data Type Declaration and Usage
Date 2011-11-15 22:17 +0000
Organization A noiseless patient Spider
Message-ID <j9uoe1$gom$2@dont-email.me> (permalink)
References <MPG.292c81c3a91936999896cd@news.eternal-september.org>

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On Tue, 15 Nov 2011 14:04:25 -0700, Mike Copeland wrote:

> I need to declare an enormous array (100,000 members) of a small scalar
> object, and I want to populate it with default values and change some of
> them as needed throughout the processing.  The range of distinct values
> for each element is 0-15, so I could use a 4 bit "mini-byte" if
> something like that existed.
>    My question is: can I declare a bit structure data type and use it
> this way?  If that's possible, I don't know how to do so, nor how I'd
> manipulate the data values in it.  Please advise.  TIA

Dead easy.

type Element is range 0 .. 15;
constant Default_Element : Element := 1;
For Element'size use 4;
type Element_Array is array (range 1 .. 100000) of Element 
		:= (others => Default_Element);

oops, this is comp.lang.c++. Sorry.

- Brian

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Thread

Special Data Type Declaration and Usage mrc2323@cox.net (Mike Copeland) - 2011-11-15 14:04 -0700
  Re: Special Data Type Declaration and Usage Ian Collins <ian-news@hotmail.com> - 2011-11-16 10:09 +1300
  Re: Special Data Type Declaration and Usage "Gennaro Prota" <gennaro.prota+Usenet@gmail.com> - 2011-11-15 22:16 +0100
    Re: Special Data Type Declaration and Usage mrc2323@cox.net (Mike Copeland) - 2011-11-15 14:30 -0700
      Re: Special Data Type Declaration and Usage Ian Collins <ian-news@hotmail.com> - 2011-11-16 10:36 +1300
        Re: Special Data Type Declaration and Usage mrc2323@cox.net (Mike Copeland) - 2011-11-15 15:02 -0700
          Re: Special Data Type Declaration and Usage Victor Bazarov <v.bazarov@comcast.invalid> - 2011-11-15 18:10 -0500
      Re: Special Data Type Declaration and Usage "Gennaro Prota" <gennaro.prota+Usenet@gmail.com> - 2011-11-15 23:58 +0100
      Re: Special Data Type Declaration and Usage Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-16 06:42 -0800
        Re: Special Data Type Declaration and Usage Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-11-16 17:16 +0000
          Re: Special Data Type Declaration and Usage Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-17 00:04 -0800
  Re: Special Data Type Declaration and Usage Brian Drummond <brian@shapes.demon.co.uk> - 2011-11-15 22:17 +0000
  Re: Special Data Type Declaration and Usage Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-11-15 22:19 +0000
    Re: Special Data Type Declaration and Usage Ian Collins <ian-news@hotmail.com> - 2011-11-16 11:51 +1300
      Re: Special Data Type Declaration and Usage Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-11-16 00:27 +0000
  Re: Special Data Type Declaration and Usage Paavo Helde <myfirstname@osa.pri.ee> - 2011-11-15 16:28 -0600

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