One option is to have another abstract subclass, to use as the superclass for all implementations which do want to use the default implementation. Personally I usually leave non-final methods abstract in an abstract class (or just use interfaces instead) but it definitely depends on the situation. If you have an interface with many methods, … Read more
The function is defined here: // startTimer adds t to the timer heap. //go:linkname startTimer time.startTimer func startTimer(t *timer) { if raceenabled { racerelease(unsafe.Pointer(t)) } addtimer(t) } Function declarations: A function declaration may omit the body. Such a declaration provides the signature for a function implemented outside Go, such as an assembly routine. Not every … Read more
Your issue comes because you have defined the abstract methods in your base abstract class with __ (double underscore) prepended. This causes python to do name mangling at the time of definition of the classes. The names of the function change from __json_builder to _Base__json_builder or __xml_builder to _Base__xml_builder . And this is the name … Read more
There is no direct compiler-enforced way to do this, as far as I know. You could work around it by not making the parent class instantiable, but instead providing a factory method that creates an instance of some (possible private) subclass that has the default implementation: public abstract class Base { public static Base create() … Read more
I know the basic use of abstract classes is to create templates for future classes. But are there any more uses of them? Not only can you define a template for children, but Abstract Classes offer the added benefit of letting you define the functionality that your child classes can utilize later. You could not … Read more
Are you using python3 to run that code? If yes, you should know that declaring metaclass in python3 have changes you should do it like this instead: import abc class AbstractClass(metaclass=abc.ABCMeta): @abc.abstractmethod def abstractMethod(self): return The full code and the explanation behind the answer is: import abc class AbstractClass(metaclass=abc.ABCMeta): @abc.abstractmethod def abstractMethod(self): return class ConcreteClass(AbstractClass): … Read more