if(int a = 0) lowered to "if (int a = (int a = 1;) , a)" ?

[Jonathan M Davis]

On Wednesday, August 8, 2018 5:58:50 AM MDT aliak via Digitalmars-d-learn 
wrote:
> Found this out while just looking at lowerings. Wondering if
> anyone knows the semantics involved here and where they are
> documented?

It's particularly useful when dealing with stuff like C functions that
return 0 on success or getting values from AAs. e.g.

if(auto value = key in aa)
{
}

> And, is there anyway to do it with multiple variables?
>
> I.e.
>
> if (int a = 0, int b = 0) {
>   // ...
> }

I don't believe so.

- Jonathan M Davis