Cast class reference to pointer of another class?

[ag0aep6g]

On Saturday, 29 May 2021 at 21:01:14 UTC, JN wrote:
> this code compiles. Why? What is even the result in "f" in this 
> case?

On Saturday, 29 May 2021 at 21:03:12 UTC, JN wrote:
> fixed formatting:
>
> ```d
> struct Foo
> {
> }
>
> class Bar
> {
> }
>
> void main()
> {
>     Bar b = new Bar();
>     Foo* f = cast(Foo*)b;
> }
> ```

You're writing @system code, so dangerous casts are allowed. It's 
no surprise that the code compiles. If you want to be safeguarded 
against such things, use @safe.

The result is a class object being reinterpreted as a struct 
object. Usually, that's just nonsense. But it might be useful for 
some expert who wants to tinker with the object's internals.