Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.std.c++ > #631

Re: A preprocessor feature we should have had 40 years ago

Cross-posted to 2 groups.

Show all headers | View raw

> On 5/30/2013 6:40 PM, Peter wrote:
>
>
> Over many years, I have heard two main arguments against this kind of
> feature.
>
> The first is the "slippery slope" argument. Where do you stop? What
> about a preprocessor-while statement? A preprocessor-for statement?
> Arithmetic statements? A library of string functions? A library of
> arithmetic functions? User-written preprocessor functions? Etc, etc.
> Over the years I have had occasions where all of these would have been
> useful. It would be very hard to draw a line, but all the imaginable
> and useful features could result in a mess.


A simple 0 to n-1 count seems like a likely stopping point. (My more
fanciful string-to-char iterator is perhaps a bridge too far.) A
"while" construct doesn't make much sense, since there is nothing that
can change value in an unpredictable manner in the preprocessor, and
that therefore can't be boiled down to a simple count.

> The second argument is, if you want that, you can create it. In many,
> if not most, programming environments, it would be simple to insert a
> customized preprocessor into the compilation sequence. You just have
> to write it, and use it. There are in fact a few extended
> preprocessors out there. I have had occasion to use tools like 'sed'
> as a preprocessor.


That creates a barrier to distribution, because you can no longer just
ship some .cpp and .h files; you also have to ship either an
executable tool for whatever platform someone might wish to compile
the program with, or source for the executable tool; and then you have
to provide a customized makefile for the program that includes the
appropriate rule, which presumes the use of a particular make utility
since they're not standardized the way the language is.

Oh, well.

--

Ciao,           Paul D. DeRocco
Paul            mailto:pderocco@ix.netcom.com


[ comp.std.c++ is moderated.  To submit articles, try posting with your ]
[ newsreader.  If that fails, use mailto:std-cpp-submit@vandevoorde.com ]
[              --- Please see the FAQ before posting. ---               ]
[ FAQ: http://www.comeaucomputing.com/csc/faq.html                      ]

Back to comp.std.c++ | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

A preprocessor feature we should have had 40 years ago "Paul D. DeRocco" <pderocco@ix.netcom.com> - 2013-05-23 19:18 -0600
  Re: A preprocessor feature we should have had 40 years ago Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-05-24 15:19 -0700
  Re: A preprocessor feature we should have had 40 years ago jacob navia <jacob@spamsink.net> - 2013-05-25 02:23 -0700
  Re: A preprocessor feature we should have had 40 years ago Keith Thompson <kst-u@mib.org> - 2013-05-25 02:24 -0700
    Re: A preprocessor feature we should have had 40 years ago "Kenneth \"Bessarion\" Boyd" <zaimoni@zaimoni.com> - 2013-05-25 23:43 -0700
    Re: A preprocessor feature we should have had 40 years ago "Paul D. DeRocco" <pderocco@ix.netcom.com> - 2013-05-25 23:44 -0700
      Re: A preprocessor feature we should have had 40 years ago Francis Glassborow <francis.glassborow@btinternet.com> - 2013-05-26 08:52 -0600
  Re: A preprocessor feature we should have had 40 years ago Rui Maciel <rui.maciel@googlemail.com> - 2013-05-25 23:43 -0700
  Re: A preprocessor feature we should have had 40 years ago Peter <pcurran88@googlemail.com> - 2013-05-30 19:40 -0600
    Re: A preprocessor feature we should have had 40 years ago "Paul D. DeRocco" <pderocco@ix.netcom.com> - 2013-06-01 02:04 -0600
      Re: A preprocessor feature we should have had 40 years ago ootiib@hot.ee - 2013-06-01 14:53 -0600
      Re: A preprocessor feature we should have had 40 years ago James Kuyper <jameskuyper@verizon.net> - 2013-06-04 10:41 -0600
        Re: A preprocessor feature we should have had 40 years ago espie@lain.home (Marc Espie) - 2013-06-05 23:12 -0700
          Re: A preprocessor feature we should have had 40 years ago James Kuyper <jameskuyper@verizon.net> - 2013-06-06 09:20 -0700
  Re: A preprocessor feature we should have had 40 years ago Jens Schweikhardt <usenet@schweikhardt.net> - 2013-06-09 02:21 -0700

csiph-web