C++ allows the use of abstract classes. Abstract classes cannot be used in programs (instantiated) directly; their only purpose is to serve as a base class from which programmers can derive other classes that can be used.
An abstract class in C++ is defined as a class that has one or more 'pure virtual' methods. These can be identified in the C++ header files or C++ docs as methods set equal to 0, for example:
virtual int somePureVirtualMethod (int a) = 0; |
To derive a useful class from the abstract class, the programmer has to write methods to overload each of the pure virtual methods. Following a suggestion on the mailing list, these docs attempt to flag all abstract classes and identify the pure virtual methods which must be overloaded in the derived class. Derived classes can be created in Python by writing Python methods to overload the pure virtual methods - no C++ code is required.