On Saturday, 28 December 2019 at 20:47:38 UTC, Mike Parker wrote:
On Saturday, 28 December 2019 at 20:22:51 UTC, JN wrote:
import std.stdio;
class Base
{
bool b = true;
}
class Derived : Base
{
bool b = false;
}
void main()
{
// 1
Base b = new Derived();
writeln(b.b); // true
// 2
Derived d = new Derived();
writeln(d.b); // false
}
Expected behavior or bug? 1) seems like a bug to me.
Expected. Member variables do not override base class
variables. b is declared as Base, so it knows nothing about
Derived’s member variable even though you instantiated it with
an instance of Derived. There’s no vtable for variables. If you
want it to print false, then you either have to cast b to
Derived or provide a getter function in Base that Derived can
override.
What Mike is saying is that `Base` has one `b` member variable,
but `Derived` has two (!).
```
writeln(d.b); // false
writeln(d.Base.b); // true (the `b` member inherited from Base)
```
-Johan
