Built-in and custom operators

Now that we understand how generic procedures work, we can take the next step and dig deeper into operators–what they are, how they work, and how you can make your own. This is a big topic, and in this chapter we’ll take only a small bite. Here, we’ll learn how to express the generic functions that we wrote for the weather average calculations as custom operators. This will also serve as a warm-up for the big and powerful topic of custom operators for derived types, which we’ll explore in the next chapter.