public inbox for gcc@gcc.gnu.org
 help / color / mirror / Atom feed
From: David Brown <david@westcontrol.com>
To: mathog <mathog@caltech.edu>
Cc: gcc@gcc.gnu.org
Subject: Re: [bool wrapping] Request for warnings on implicit bool to int conversions
Date: Thu, 29 Mar 2012 10:29:00 -0000	[thread overview]
Message-ID: <4F743777.6040409@westcontrol.com> (raw)
In-Reply-To: <b0e87afec2593121c5c332b84fabf1f4@saf.bio.caltech.edu>

On 29/03/2012 00:52, mathog wrote:
> On 28-Mar-2012 15:20, Michael Witten wrote:
>
>> However, it seems to me that toggling the value with the idiom:
>>
>> --b;
>>
>> is aesthetically preferable to the more elaborate:
>>
>> b = !b;
>
> Aesthetically, not logically. Neither of these makes the least bit of
> sense:
>
> one less than False
> one less than True
>
> A better solution for the aesthetics would have been (it is a bit late
> now) to implement the missing unary negation operator:
>
> !!b; //T->F, F->T
>

You can't do that, because "!!" is already a useful operator on integers 
- it turns anything non-zero into 1 while leaving 0 alone, and is 
effectively an "int to bool" conversion operator.

> That operator would save even more program characters for the other int
> types, where it would be equivalent to:
>
> (i==0 ? 1 : 0);
>
>
> Regards,
>
> David Mathog
> mathog@caltech.edu
> Manager, Sequence Analysis Facility, Biology Division, Caltech
>

  reply	other threads:[~2012-03-29 10:29 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-27 22:43 mathog
2012-03-28  1:00 ` Paolo Carlini
2012-03-28  1:19   ` Gabriel Dos Reis
2012-03-28  2:21     ` Russ Allbery
2012-03-28  2:30       ` Gabriel Dos Reis
2012-03-28  2:40         ` Russ Allbery
2012-03-28  2:48           ` Russ Allbery
2012-03-28 19:32       ` [bool wrapping] " Michael Witten
2012-03-28 20:30         ` mathog
2012-03-28 22:21           ` Michael Witten
2012-03-28 22:52             ` mathog
2012-03-29 10:29               ` David Brown [this message]
2012-03-29 17:49                 ` mathog
2012-03-28 22:28           ` Michael Witten
2012-03-28  9:00 ` Franz Sirl

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4F743777.6040409@westcontrol.com \
    --to=david@westcontrol.com \
    --cc=gcc@gcc.gnu.org \
    --cc=mathog@caltech.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).