Introduction

Recap

In the previous chapter, we learned to use concepts with function templates and now we’ll use them with class templates. We learned there are four ways to use concepts:

• The requires clause
• The trailing requires clause
• Constrained template parameters
• Abbreviated function templates

With classes, we can’t use the abbreviated function template form because this form is only for templates.

We could try to do it, but we’ll get a compile-time error, as shown below.