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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Getting sensible information from gdb
Date: Mon, 12 Oct 2015 08:00:55 -0700
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"Morten W. Petersen" <morphex@gmail.com> writes:
> On 12.10.2015 06:59, Ian Collins wrote:
[...]
>> "#define CONST const"
>>
>> Why would you male const optional?  What is const is and what isn't isn't!
>
> Profiling.  What are the speed benefits of constants..  mostly
> out of curiosity.

"const" and "constant" are two very different things, even though
the keyword "const" is obviously derived from the English word
"constant".

The "const" keyword really means "read-only".  A "constant" is a
literal, such as 42, 1.23, or 'x'.  A "constant expression" is one
that can be evaluated at compile time.

For example, this:
    const int r = rand();
is perfectly valid and meaningful; r is const, but obviously not
constant.

[...]

-- 
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"