Solution

The purpose of this Item was to provoke thought about major (and even missing) features in C++, and to provide a healthy dose of reality. Specifically, I hope that your thinking about this Item has generated ideas and examples that illustrate three main things.

1. Not everyone agrees about what OO means. "Well, what is object orientation, anyway?" Even at this late date, if you ask 10 people, you're likely to get 15 different answers. (Not much better than asking 10 lawyers for legal opinions.)

   Just about everyone would agree that inheritance and polymorphism are OO concepts. Most people would include encapsulation. A few might include exception handling, and perhaps no one would include templates. The point is that there are differing opinions on whether any given feature is OO, and each viewpoint has its passionate defenders.

2. C++ is a multiparadigm language. C++ is not just an OO language. It supports many OO features, but it doesn't force programmers to use them. You can write completely non-OO programs in C++, and many people do.

   The C++ standardization effort's most important contribution to C++ is stronger support for powerful abstraction to reduce software complexity (Martin95).^[12] C++ is not solely an object-oriented language. It supports several programming styles, including both object-oriented programming and generic programming. These styles are fundamentally important because each provides flexible ways to organize code through abstraction. Object-oriented programming lets us bundle an object's state together with the functions that manipulate it, and encapsulation and inheritance let us manage interdependencies and make reuse cleaner and easier. Generic programming is a more recent style that lets us write functions and classes that operate on other functions and objects of unspecified, unrelated, and unknown types, providing a unique way to reduce coupling and interdependencies within a program. A few other languages currently provide support for genericity, but none yet support it as strongly as C++. Indeed, modern generic programming was made possible by the unique C++ formulation of templates.

   ^[12] The book contains an excellent discussion of why one of object-oriented programming's most important benefits is that it lets us reduce software complexity by managing code interdependencies.

   Today, C++ provides many powerful ways to express abstraction, and the resulting flexibility is the most important result of C++ standardization.

3. No language is the be-all and end-all. Today, I'm using C++ as my primary programming language; tomorrow, I'll use whatever best suits what I'm doing then. C++ does not have a module system (complete or otherwise); it lacks other major features, such as garbage collection; and it has static typing, but not necessarily "strong" typing. All languages have advantages and drawbacks. Just pick the right tool for the job, and avoid the temptation to become a nearsighted language zealot.