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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: "C's Biggest Mistake"
Date: Thu, 05 Apr 2018 10:55:40 -0700
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David Brown <david.brown@hesbynett.no> writes:
[...]
> Allowing assignment in an expression is useful for C idioms such as:
>
> 	while (c = next_char()) ...

Perhaps not the best example.  That tests whether next_char() returned
'\0'.  It's more common to use EOF (typically -1) as a sentinel value.

But it's a useful idiom when 0 is used as a sentinel value, for example
with a function that returns a pointer.

Personally, I'd make the comparison explicit:

    while ((p = next_pointer()) != NULL) ...

but using the implicit comparison to 0/NULL is perfectly valid.

[...]

-- 
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"