import std.stdio;

​

class A {

    bool boolean = false;

    abstract void foo();

}

​

class B : A {

    bool boolean = false;//delete this line, and everything works as expected

    override void foo() {

        boolean = true;

    }

}

​

void main() {

    A castedB = cast(A) new B();

    writeln(castedB.boolean);

    castedB.foo();//should call A.foo(), changing boolean to true...

    writeln(castedB.boolean);//...but here, boolean is still false

}