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Runtime Polymorphism · 3:49
Abstract Classes as Interfaces
How can one function work with many kinds of container without knowing which one it was handed? We build Stroustrup's Container interface with pure virtual functions, implement it twice (a vector and a linked list), watch the same call land in different code, and see why polymorphic objects are used through references and pointers rather than stored by value.
You will learn
- Declare an interface with pure virtual functions (= 0)
- Explain why an abstract class can't be instantiated
- Implement an interface in derived classes and mark the functions override
- Explain why polymorphic objects are held through references or pointers, not by value