Rebind template(bug?)

[Engine Machine via Digitalmars-d-learn]

On Sunday, 21 August 2016 at 19:42:08 UTC, Lodovico Giaretta 
wrote:
> On Sunday, 21 August 2016 at 19:29:26 UTC, Engine Machine wrote:
>> [...]
>
> The problem of this code has nothing to do with aliases. They 
> work correctly. The problem is variable shadowing. In the 
> following code, Child has two x variables, one of which is only 
> accessible from a Parent reference, the other only from a Child 
> reference.
>
> class Parent
> {
>     int x;
> }
> class Child: Parent
> {
>     int x; // this shadows Parent.x
>     int y;
> }
>
> void main()
> {
>     Child child = new Child();
>     Parent parent = child;
>
>     child.x = child.y = 3;
>     parent.x = 2;
>
>     assert(child.x == 3);
>     assert((cast(Child)parent).x == 3);
>     assert((cast(Parent)child).x == 2);
>
>     assert(parent is child); // same object (remember that a 
> class is already a pointer);
>     assert(&parent != &child); // but there are two different 
> pointers on the stack (pointing to the same object)
> }

You're right. I didn't realize that variables could be shadowed 
in classes. Seems dangerous. D doesn't allow shadowing in a 
normal context and gives an error so I don't know why it wouldn't 
do that in classes. (since it wasn't giving an error I thought it 
wasn't shadowing)