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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Range-aware modulo operator -%
Date: Tue, 01 Jan 2019 17:53:18 -0800
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Bart <bc@freeuk.com> writes:
> On 02/01/2019 00:09, Keith Thompson wrote:
[...]
>> But I'm curious, do you understand the description in the standard?
>> Did you even know what it said before I pointed it out?
>
> You mean 6.8.4.1p2? No I don't remember looking at it before.

So you've been describing how conditions work in C without knowing what
the standard says about them.

> I don't think such expressions in C are much different from many other 
> languages, and I've implemented this too many times to be in need of 
> such guidance.
>
> The text talks about comparing the expression with 0, which is fine for 
> a programmer, but an implementer (this one, anyway) prefers it pinned 
> down a little more.

The description in the standard tells you everything you need to know to
implement it, if you're willing to think about it a little.

> Since an equality comparison with 0 might need to take account of 
> multiple widths, and several types (int, pointer, float). A pseudo-bool 
> result is just one type, not even a width when there is no actual bool type.

A comparison with 0 may require a type conversion, as clearly described
by the C standard.

> (Also, with certain languages I implement,
[snip]

We were talking about C.  Of course if you're implementing something
other than C, you should follow the rules of that language.

[...]

-- 
Keith Thompson (The_Other_Keith) kst@mib.org  <http://www.ghoti.net/~kst>
Will write code for food.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"