illegal void argument topic

On 29.01.2014 16:04, Öö Tiib wrote:
> In C++ we can have void return type and we can "return" it:
>
> void foo();
>
> void bar()
> {
> return (void)42; // ok #1
> return foo(); // ok #2
> }
>
> Fun way to confuse novices indeed. However, it appears that we can not (for
> whatever unknown reason) pass void arguments:
>
> void bad()
> {
> foo((void)42); // illegal
> }
>
> Even if I think I will be extra clever and add overload of 'foo' that supposedly
> accepts anything ...
>
> void foo(...);
>
> ... then I get different failures or successes on different mac/ubuntu clang/gcc
> versions. Seems that compilers are confused.
>
> Is there reason why we have such inconsistency?
>

`(void)` as a formal argument list doesn't indicate a formal argument of
type `void`. It's just a special syntax from C, where it specifies that
the function really doesn't take *any* arguments, at all.

In C++ the special syntax is unnecessary, since in C++ `()` also says
that, but the special syntax is supported for C compatibility.

Also baffling: why you can create a "void value" via `void()`. I guess
for uniform treatment in template code. But still it's kind of
inconsistent with the basic idea of `void` as an incomplete type.


Cheers & hth.,

- Alf