Summary

In this chapter, you learned the difference between lazy evaluation and eager evaluation. You also learned how to use hidden proxy objects to implement lazy evaluation behind the scenes, meaning that you now understand how to implement lazy evaluation optimizations while preserving the easy-to-use interface of your classes. Hiding complex optimizations inside library classes instead of having them exposed in the application code makes the application code more readable and less error-prone.

In the next chapter, we will shift focus and move on to concurrent and parallel programming using C++.