Bug 1289 – Class method without a function body should be abstract?

The spec should state whether a method without a body is abstract or not. Of course this also affects the behavior of compiler. For instance this fails when linking: class A { A f(); } class B : A { B f() { return this; } } void main() { B a = new B(); } In some occasions similar code works, in others it doesn't.

This is working as designed. It allows one to implement a member function elsewhere than the class definition. To have an abstract class, it must have the 'abstract' storage class.