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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Spurious diagnostic messages
Date: Wed, 27 May 2015 10:40:38 -0700
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Morris Dovey <mrdovey@iedu.com> writes:
[...]
> One that I've wondered about from time to time is
>
>    switch (x)
>    {  case { expression }:
>          /* case code */
>       /* other cases */
>    }
>
> where <expression> is code that examines x and yields TRUE (execute
> case code) or FALSE (do not execute case code) – of which an
> interesting subset/derivative possibility might be:
>
>    switch (x)
>    {  case { function(x) }:
>          /* case code */
>       /* other cases */
>    }
>
> which causes the named function to be invoked to produce the
> TRUE/FALSE result.

What's the point of specifying x in `switch (x)`?  Can the expression
refer to things other than x?  If it can't, it seems like an odd
restriction.  If it can, it's just an if/else in disguise.

> C actually does have a (primitive) range-testing feature:
>
>    if (x >= lower_bound && x <= upper_bound) /* x in range! */;
>
> :-)

-- 
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"