Variadic Struct Parameter

[Jonathan Levi]

On Tuesday, 12 January 2021 at 17:46:14 UTC, Q. Schroll wrote:
> It's obvious why arrays work, it's the primary use case. I have 
> no idea why classes are allowed. That classes are allowed, but 
> structs are not, makes no sense to me.

I like the variadic feature for classes, but I wish it worked for 
structs as well, given that structs are value types on the stack 
anyway, the same assembly could have either signature (assuming 
matching argument/struct ordering).

But why does this compile?

```
struct S {/*...*/}

void fun(S s...) {/*...*/}
```
If structs do not work as variadic parameters, why does `fun` 
still compile?