Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
| From | Nobody <nobody@nowhere.com> |
|---|---|
| Subject | Re: Array sizes and const |
| Date | 2012-06-02 23:50 +0100 |
| Message-Id | <pan.2012.06.02.22.50.02.517000@nowhere.com> |
| Newsgroups | comp.lang.c |
| References | <jqdtou$koe$1@dont-email.me> |
| Organization | Zen Internet |
On Sat, 02 Jun 2012 15:43:40 -0500, Les Cargill wrote:
> And yes, I understand/speak/grok preprocessor vs.
> compiler. I know *how*, I just wonder *why*. Is
> this a practical, strategic or tactical thing,
> or am I just being silly? Was it a conscious decision
> of the committee, or just one of those things?
K&R C didn't have "const". Along with "volatile", it was added during the
standardisation process to facilitate optimisation.
The main purpose of "const" is to tell the compiler to assume that the
value won't change. However, a const-qualified variable is still an
lvalue, not a compile-time constant; changing that was presumably
considered too radical.
If you want a compile-time integer constant, you can use enum, e.g.:
enum { size = SIZE };
This "trick" is still quite common in C++ code due to some compilers being
a bit late to accept that a "static const" member really is a compile-time
constant in C++, and the preprocessor not being an acceptable substitute
when the name has to belong to a class or namespace.
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Array sizes and const Les Cargill <lcargill99@comcast.com> - 2012-06-02 15:43 -0500
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-03 08:56 +1200
Re: Array sizes and const Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-06-02 16:59 -0400
Re: Array sizes and const Les Cargill <lcargill99@comcast.com> - 2012-06-02 16:35 -0500
Re: Array sizes and const jgk@panix.com (Joe keane) - 2012-06-08 20:05 +0000
Re: Array sizes and const jgk@panix.com (Joe keane) - 2012-06-09 21:36 +0000
Re: Array sizes and const Les Cargill <lcargill99@comcast.com> - 2012-06-02 16:43 -0500
Re: Array sizes and const Keith Thompson <kst-u@mib.org> - 2012-06-02 14:59 -0700
Re: Array sizes and const Les Cargill <lcargill99@comcast.com> - 2012-06-02 17:12 -0500
Re: Array sizes and const Keith Thompson <kst-u@mib.org> - 2012-06-02 18:27 -0700
Re: Array sizes and const Les Cargill <lcargill99@comcast.com> - 2012-06-02 22:27 -0500
Re: Array sizes and const "BartC" <bc@freeuk.com> - 2012-06-03 11:24 +0100
Re: Array sizes and const Keith Thompson <kst-u@mib.org> - 2012-06-03 13:51 -0700
Re: Array sizes and const "BartC" <bc@freeuk.com> - 2012-06-04 12:20 +0100
Re: Array sizes and const Jens Gustedt <jens.gustedt@loria.fr> - 2012-06-04 13:54 +0200
Re: Array sizes and const Keith Thompson <kst-u@mib.org> - 2012-06-04 14:32 -0700
Re: Array sizes and const Nobody <nobody@nowhere.com> - 2012-06-02 23:50 +0100
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-03 10:53 +1200
Re: Array sizes and const Nobody <nobody@nowhere.com> - 2012-06-03 14:35 +0100
Re: Array sizes and const James Kuyper <jameskuyper@verizon.net> - 2012-06-02 21:11 -0400
Re: Array sizes and const Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-06-03 07:39 -0700
Re: Array sizes and const James Kuyper <jameskuyper@verizon.net> - 2012-06-03 16:03 -0400
Re: Array sizes and const Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-03 21:49 +0100
Re: Array sizes and const Keith Thompson <kst-u@mib.org> - 2012-06-03 14:49 -0700
Re: Array sizes and const Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-06-03 15:02 -0700
Re: Array sizes and const Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-04 01:21 +0100
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-04 09:08 +1200
Re: Array sizes and const Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-06-03 15:08 -0700
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-04 10:37 +1200
Re: Array sizes and const "BartC" <bc@freeuk.com> - 2012-06-03 23:47 +0100
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-04 10:55 +1200
Re: Array sizes and const Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-06-03 16:04 -0700
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-04 11:14 +1200
Re: Array sizes and const "BartC" <bc@freeuk.com> - 2012-06-04 00:23 +0100
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-04 11:30 +1200
Re: Array sizes and const "BartC" <bc@freeuk.com> - 2012-06-04 00:52 +0100
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-04 12:04 +1200
Re: Array sizes and const Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-04 01:39 +0100
Re: Array sizes and const Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-06-04 02:35 -0700
Re: Array sizes and const Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-06-04 01:33 +0100
Re: Array sizes and const Ian Collins <ian-news@hotmail.com> - 2012-06-04 12:35 +1200
Re: Array sizes and const pacman@kosh.dhis.org (Alan Curry) - 2012-06-04 21:28 +0000
Re: Array sizes and const James Kuyper <jameskuyper@verizon.net> - 2012-06-04 12:08 -0400
Re: Array sizes and const jgk@panix.com (Joe keane) - 2012-06-04 22:49 +0000
Re: Array sizes and const David Brown <david.brown@hesbynett.no> - 2012-06-03 15:46 -0500
Re: Array sizes and const Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-08 02:08 -0700
Re: Array sizes and const Les Cargill <lcargill99@comcast.com> - 2012-06-08 06:45 -0500
Re: Array sizes and const Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-08 10:49 -0700
Re: Array sizes and const Les Cargill <lcargill99@comcast.com> - 2012-06-08 18:05 -0500
Re: Array sizes and const Keith Thompson <kst-u@mib.org> - 2012-06-08 13:31 -0700
Re: Array sizes and const Tim Rentsch <txr@alumni.caltech.edu> - 2012-06-08 20:30 -0700
csiph-web