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Groups > comp.lang.c > #104414

Re: modifying local const variable run time

From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: modifying local const variable run time
Date 2017-02-22 15:20 -0800
Organization None to speak of
Message-ID <lno9xtke23.fsf@kst-u.example.com> (permalink)
References (3 earlier) <20170222173450.4fe314b3c852b242bb2dc35a@gmail.com> <ln1suqkul5.fsf@kst-u.example.com> <20170222183223.a4daa256d17cc9bfcc04d4b9@gmail.com> <lnshn6jesv.fsf@kst-u.example.com> <o8l1uk$eh$3@dont-email.me>

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David Brown <david.brown@hesbynett.no> writes:
> On 22/02/17 18:50, Keith Thompson wrote:
[...]
>> Personally, I use "const" mostly to make code clearer, so it's
>> obvious at a glance to a human reader that a given object won't
>> be modified, and so that the compiler can diagnose any incorrect
>> attempt to modify it.  If a compiler can use that information to
>> generate faster code, so much the better.
>
> Or more importantly, if the compiler can use that information to spot 
> mistakes in the code - accidentally modifying the const object - then so 
> much the better.  That's why the "const" keyword is much better than a 
> "const" comment would have been, even if the comment were equally 
> readable to humans.

I believe you're repeating part of what I wrote: "... and so that the
compiler can diagnose any incorrect attempt to modify it".

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

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Thread

modifying local const variable run time rahul.dev.agg@gmail.com - 2017-02-22 06:39 -0800
  Re: modifying local const variable run time GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-02-22 16:06 +0100
    Re: modifying local const variable run time rahul.dev.agg@gmail.com - 2017-02-22 07:26 -0800
      Re: modifying local const variable run time David Brown <david.brown@hesbynett.no> - 2017-02-22 16:31 +0100
        Re: modifying local const variable run time rahul.dev.agg@gmail.com - 2017-02-22 07:43 -0800
          Re: modifying local const variable run time Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-22 16:06 +0000
      Re: modifying local const variable run time James Kuyper <jameskuyper@verizon.net> - 2017-02-22 11:13 -0500
      Re: modifying local const variable run time supercat@casperkitty.com - 2017-02-22 08:34 -0800
        Re: modifying local const variable run time David Brown <david.brown@hesbynett.no> - 2017-02-22 23:03 +0100
      Re: modifying local const variable run time GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-02-22 17:34 +0100
        Re: modifying local const variable run time Robert Wessel <robertwessel2@yahoo.com> - 2017-02-22 10:52 -0600
          Re: modifying local const variable run time GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-02-22 17:52 +0100
            Re: modifying local const variable run time Keith Thompson <kst-u@mib.org> - 2017-02-22 09:33 -0800
            Re: modifying local const variable run time James Kuyper <jameskuyper@verizon.net> - 2017-02-22 15:50 -0500
              Re: modifying local const variable run time supercat@casperkitty.com - 2017-02-22 13:13 -0800
                Re: modifying local const variable run time Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-22 21:55 +0000
                Re: modifying local const variable run time supercat@casperkitty.com - 2017-02-22 14:43 -0800
        Re: modifying local const variable run time Keith Thompson <kst-u@mib.org> - 2017-02-22 09:23 -0800
          Re: modifying local const variable run time GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-02-22 18:32 +0100
            Re: modifying local const variable run time Keith Thompson <kst-u@mib.org> - 2017-02-22 09:50 -0800
              Re: modifying local const variable run time David Brown <david.brown@hesbynett.no> - 2017-02-22 23:07 +0100
                Re: modifying local const variable run time Keith Thompson <kst-u@mib.org> - 2017-02-22 15:20 -0800
                Re: modifying local const variable run time David Brown <david.brown@hesbynett.no> - 2017-02-23 09:50 +0100
  Re: modifying local const variable run time James Kuyper <jameskuyper@verizon.net> - 2017-02-22 10:16 -0500
  Re: modifying local const variable run time Keith Thompson <kst-u@mib.org> - 2017-02-22 09:17 -0800

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