If I understand correctly, this piece of code:
    enum NOTUSED(v) do { (void)(1 ? (void)0 : ( (void)(v) ) ); } while(0)

can be converted to the following in D:

    void notUsed(T)(T v) { return cast(void)0; };

since it always returns cast(void)0 regardless of the input.

But it cannot be that simple, so what am I missing?

Thanks,
Andrew Edwards

On Sunday, 31 January 2016 at 02:58:28 UTC, Andrew Edwards wrote:
> But it cannot be that simple, so what am I missing?

I'm guessing the macro was there in C to silence compiler warnings about not using a return value. So I think your translation is ok:

NOTUSED(somefunction(....));

still calls the function, so the behavior is the same. If I'm right, the macro was just about discarding the return value in such a way as to tell the compiler warning / lint program that you intentionally wanted to ignore it.

On Sunday, 31 January 2016 at 03:13:46 UTC, Adam D. Ruppe wrote:
> On Sunday, 31 January 2016 at 02:58:28 UTC, Andrew Edwards wrote:
>> But it cannot be that simple, so what am I missing?
>
> I'm guessing the macro was there in C to silence compiler warnings about not using a return value. So I think your translation is ok:
>
> NOTUSED(somefunction(....));
>
> still calls the function, so the behavior is the same. If I'm right, the macro was just about discarding the return value in such a way as to tell the compiler warning / lint program that you intentionally wanted to ignore it.

Okay, got it. Much appreciated.

On Sunday, 31 January 2016 at 02:58:28 UTC, Andrew Edwards wrote:
> If I understand correctly, this piece of code:
>     enum NOTUSED(v) do { (void)(1 ? (void)0 : ( (void)(v) ) ); } while(0)
>
> can be converted to the following in D:
>
>     void notUsed(T)(T v) { return cast(void)0; };
>
> since it always returns cast(void)0 regardless of the input.
>
> But it cannot be that simple, so what am I missing?
>
> Thanks,
> Andrew Edwards

Might want to change the function argument to `ref T v`, as struct postblits might run otherwise. Probably no reason to `return` either.

On Sunday, 31 January 2016 at 02:58:28 UTC, Andrew Edwards wrote:
>     void notUsed(T)(T v) { return cast(void)0; };
>
> since it always returns cast(void)0 regardless of the input.
>
> But it cannot be that simple, so what am I missing?

Now notUsed has an unused parameter v.