First Draft: Static Single Assignment

[Walter Bright]

On 11/17/2025 2:25 AM, user1234 wrote:
> which leads to ask what is the right behavior (given first note) for
> 
> ```d
> void v(final ref int);
> final int arg;
> v(arg);
> ```

This should be an error. It is equivalent to:

```d
final int arg;
ref int rarg = arg; // error
ref const(int) rarg = arg; // ok
```

I.e. a ref to a final should not be able to modify the final.