Bug 8001 – Alias this takes ownership of explicit cast

When attempting to downcast a class which uses alias this, the operation fails because the cast is applied to the item aliased. I think the semantics should be to attempt an implicit cast (alias this), then a cast of the top class, afterwards the alias this item can be casted. test.d(3): Error: e2ir: cannot cast a.val of type int to type test.B void main () { A a = new B(); B b = cast(B) a; } class A { int val; alias val this; } class B : A {}

May be connected with http://d.puremagic.com/issues/show_bug.cgi?id=6777

*** This issue has been marked as a duplicate of issue 3537 ***