Gain insights into C++20 Concepts to enhance type safety. Delve into creating compiler-checked criteria for templates and improving error clarity for seamless generic code development.

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This course will walk you through the newest version of C++ 20, C++ Concepts.

You will go through one of the most significant new features in C++20, which is Concepts. Concepts allow you to create compiler-checked criteria for template parameters, revolutionizing the way you think about and develop generic code. You can use them to provide both syntactic and semantic requirements. They also allow you to explicitly express your goal in the type system. If something goes wrong, you'll get a clear error message from the compiler.

While useful, Concepts can be difficult to apply and even confusing sometimes. This course provides you with the knowledge you need to overcome these obstacles and move on to more complex topics.

Let's get started.

C++ Concepts: Improve Type Safety with C++ 20

We have reached the end of the course! Congratulations!

Hopefully, we’re now equipped with some important skills that will help us achieve our goals. Give yourself a round of applause!


# Last few thoughts
Thank you for taking this course! Now, we have most of the necessary knowledge to write powerful C++ concepts. We should use concepts as soon as we have capable compiler.

With concepts, we can and should improve our templates! Concepts help us validate template arguments at compile-time, and they do this in a reusable and scalable way.

We could already define many of the offered constraints before C++20, but concepts make our job much easier.


While the situation significantly improved with C++17 and `if constexpr`, concepts are still a game-changer. They are extremely readable and they scale well.

The standard library provides us with about fifty thoroughly designed concepts. The [Core Guidelines](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#t-templates-and-generic-programming) recommend that we use those concepts whenever possible instead of using user-defined concepts. We can define our own concepts as well, however, if the situation calls for it.



It’s easy to write concepts, but it’s difficult to write good ones because we as a community don’t have a lot of experience in writing good concepts yet. We’ll need a couple of years to build that experience and to identify best practices. Don’t expect that our concepts will be perfect on the first try. We’ll need multiple iterations to make them right. And that’s perfectly fine!

It’s good that we have recommendations by the Core Guidelines, but they cannot replace experience. This is why we should start using concepts immediately provided that we have access to a C++20 compiler.

Experiment with concepts, learn about them, and try to understand how they can help our applications and our libraries. Remember that we should not use naked type names anymore because we almost always have some expectations towards types that are used with our templates.

Model, constrain, iterate! And keep learning!

Introduction

The Concept Behind C++ Concepts

Four Ways to use Concepts in Functions

C++ Concepts with Classes

Concepts Shipped with the C++ Standard Library

How to Write Your Own C++ Concepts

How to Use C++ Concepts in Real Life

Summary

Final Words