On Thursday, 28 March 2024 at 01:53:52 UTC, Steven Schveighoffer
wrote:
```d
class Base {}
class Derived : Base {}
@safe pure nothrow unittest {
Base b;
Derived d;
b = d; // pass
Base[] bs;
Derived[] ds;
bs ~= ds; // pass
bs = ds; // fail [1], should pass
bs = cast(Base[])ds; // fail [2], should pass
}
```
Yes, it's unsafe, as you can replace an element of `ds` with
something that has no relation to `Derived`.
This is a suggested change that when _applied_ will make the code
unsafe yes. But the code in its current form is safe and the
compiler could be extended to prove it.
