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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Preprocessor Overheads
Date: Thu, 02 Feb 2017 16:13:18 -0800
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supercat@casperkitty.com writes:
> On Thursday, February 2, 2017 at 5:20:49 PM UTC-6, Keith Thompson wrote:
>> supercat writes:
>> [...]
>> > The Standard could have specified that, but having rules which
>> > guaranteed behavior on some platforms but not others might have been
>> > seen as reflecting negatively on the platforms that worked
>> > differently--something the authors of the Standard seem to have bent
>> > over backward to avoid doing.  The dominant case by far where code
>> > would rely upon such behavior would be when passing a pointer of a
>> > particular type to a function which expects a void*, which would be
>> > permissible without a cast in cases where the prototype is in scope.
>> [...]
>> 
>> What?  In such cases the pointer is converted.
>> 
>>     void func(void *param);
>> 
>>     int *p = NULL;
>>     func(p);
>> 
>> The value of p is converted from int* to void*.  On some systems, that
>> conversion is trivial; on others it might not be.
>
> In the days before prototypes,
[...]

We are no longer in the days before prototypes.

-- 
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"