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Re: correct way to create dynamically function pointers

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Richard Heathfield <rjh@cpax.org.uk> writes:
> On 12/04/17 22:17, Spiros Bousbouras wrote:
>> On Wed, 12 Apr 2017 08:19:00 +0100
>> Richard Heathfield <rjh@cpax.org.uk> wrote:
[...]
>>>      printf("p[0](4, 6) = %d\n",(*p[0])(4, 6));
>>
>> Or more simply
>>        printf("p[0](4, 6) = %d\n",p[0](4, 6));
>
> I disagree that it's necessarily simpler. It's /shorter/, yes.

In any case, it would be nice for the expression in the format string to
match the function call.

> But (*p[0]) tells us something useful - i.e. it reminds us that p[0] is 
> a pointer, not a function. Now, okay, I realise that p[0] can't be the 
> name of a function! Nevertheless, in the general case I prefer to use 
> parentheses (*p)() rather than p() when a function pointer is being 
> used, as a little reminder that there's no point in going looking for a 
> function p.

I agree that it's a useful reminder.  On the other hand, the prefix to a
function call is *always* a expression of pointer-to-function type, so
if one were being deliberately perverse, one could cause great confusion
by inverting the convention:

void func(void) {
    /* ... */
}

void (*funcptr)(void) = func;

int main(void) {
    (*func)();
    funcptr();
}

Not that I'd ever doing such a thing, of course.

-- 
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"

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Thread

correct way to create dynamically function pointers Hello World <acidlategamer@gmail.com> - 2017-04-11 10:20 -0700
  Re: correct way to create dynamically function pointers scott@slp53.sl.home (Scott Lurndal) - 2017-04-11 17:34 +0000
    Re: correct way to create dynamically function pointers Hello World <acidlategamer@gmail.com> - 2017-04-11 10:42 -0700
      Re: correct way to create dynamically function pointers scott@slp53.sl.home (Scott Lurndal) - 2017-04-11 17:48 +0000
        Re: correct way to create dynamically function pointers Hello World <acidlategamer@gmail.com> - 2017-04-11 10:55 -0700
      Re: correct way to create dynamically function pointers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-04-11 19:06 +0100
      Re: correct way to create dynamically function pointers "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-11 14:23 -0400
    Re: correct way to create dynamically function pointers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-04-11 19:05 +0100
    Re: correct way to create dynamically function pointers "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-11 14:11 -0400
      Re: correct way to create dynamically function pointers Richard Heathfield <rjh@cpax.org.uk> - 2017-04-12 08:27 +0100
        Re: correct way to create dynamically function pointers "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-12 13:31 -0400
          Re: correct way to create dynamically function pointers Richard Heathfield <rjh@cpax.org.uk> - 2017-04-12 23:05 +0100
  Re: correct way to create dynamically function pointers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-04-11 19:03 +0100
  Re: correct way to create dynamically function pointers "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-11 14:05 -0400
    Re: correct way to create dynamically function pointers Jorgen Grahn <grahn+nntp@snipabacken.se> - 2017-04-15 10:19 +0000
      Re: correct way to create dynamically function pointers asetofsymbols@gmail.com - 2017-04-15 05:09 -0700
  Re: correct way to create dynamically function pointers Barry Schwarz <schwarzb@dqel.com> - 2017-04-11 15:13 -0700
    Re: correct way to create dynamically function pointers Richard Heathfield <rjh@cpax.org.uk> - 2017-04-12 08:28 +0100
  Re: correct way to create dynamically function pointers Richard Heathfield <rjh@cpax.org.uk> - 2017-04-12 08:19 +0100
    Re: correct way to create dynamically function pointers Spiros Bousbouras <spibou@gmail.com> - 2017-04-12 21:17 +0000
      Re: correct way to create dynamically function pointers Richard Heathfield <rjh@cpax.org.uk> - 2017-04-12 23:11 +0100
        Re: correct way to create dynamically function pointers Keith Thompson <kst-u@mib.org> - 2017-04-12 16:36 -0700
  Re: correct way to create dynamically function pointers John Bode <jfbode1029@gmail.com> - 2017-04-12 10:04 -0700
    Re: correct way to create dynamically function pointers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-04-12 19:28 +0100
    Re: correct way to create dynamically function pointers Tim Rentsch <txr@alumni.caltech.edu> - 2017-04-17 05:50 -0700

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