Re: Sequencing guarantees for macro versions of standard functions

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From	Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups	comp.lang.c
Subject	Re: Sequencing guarantees for macro versions of standard functions
Date	Mon, 24 Jan 2022 07:27:04 -0800
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Andrey Tarasevich <andreytarasevich@hotmail.com> writes:

> On 1/23/2022 7:56 PM, Andrey Tarasevich wrote:
>
>> On 1/23/2022 7:36 PM, Tim Rentsch wrote:
>>
>>> However, the suggested rewrite has different semantics than the
>>> previous single assignment with function call.  If we want to
>>> keep the same semantics but still be able to use the macro
>>> form (but without any sequencing issues), a different writing
>>> is needed, as for example
>>>
>>>  x = modf( x, (double[]){ 0 } );
>>>
>>> Writing the call this way should make it obvious that the value
>>> stored in/through the second argument is ignored and discarded.
>>
>> That would be
>>
>>   x = modf( x, &(double[]){ 0 } );
>
> Opps, my sitake.  Sorry, I missed the `[]` part.
>
> Of course, your original variant is correct.  Although I don't see
> the point of bringing arrays into the picture.  One can just do
>
>   x = modf( x, &(double){ 0 } );

For no particular reason I can point to (no pun intended), in
situations like this one I normally use the array type form in
preference to the & form.  I find it easier to digest, and also
think it expresses more directly what I want to convey.  I'm sure
many people would normally use the & form, and I'm okay with that
choice, but it doesn't change my choice.

Thread

Sequencing guarantees for macro versions of standard functions Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-01-20 15:59 -0800
  Re: Sequencing guarantees for macro versions of standard functions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-01-20 16:35 -0800
    Re: Sequencing guarantees for macro versions of standard functions Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-01-23 14:38 -0800
      Re: Sequencing guarantees for macro versions of standard functions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-01-23 19:36 -0800
        Re: Sequencing guarantees for macro versions of standard functions Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-01-23 19:56 -0800
          Re: Sequencing guarantees for macro versions of standard functions Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-01-23 19:58 -0800
            Re: Sequencing guarantees for macro versions of standard functions Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-01-23 23:50 -0800
            Re: Sequencing guarantees for macro versions of standard functions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-01-24 07:27 -0800
        Re: Sequencing guarantees for macro versions of standard functions Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-01-23 23:49 -0800
          Re: Sequencing guarantees for macro versions of standard functions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-01-24 07:31 -0800
            Re: Sequencing guarantees for macro versions of standard functions Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-01-24 13:18 -0800
              Re: Sequencing guarantees for macro versions of standard functions Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-01-29 03:36 -0800

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