5.9. Summary

This chapter introduced you to interfaces and how you can model a well-defined, versioned contract using an interface. Along with showing you the various ways that classes can implement interfaces, I also described the process that the C# compiler follows when matching up interface methods to implementations in the implementing class. I described interfaces from the perspective of reference types and value types—specifically, how expensive boxing operations can cause you pain when using interfaces on value types. Finally, I spent some time comparing and contrasting the use of interfaces and classes when modeling contracts between types in your design.

In the next chapter, I'll explain the intricacies of operator overloading in the C# language and why you may want to avoid it when creating code used by other .NET languages.