Gain insights into the C++ keyword 'const,' its usage in various contexts, and implications when returning pointers and references. Learn about preventing accidental data changes.

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In this course, you will learn about the C++ keyword const and its behaviour under different usage conditions, including local, global and static contexts. This course will help you to understand const and its implications when you attempt to return pointers and references in C++. By the end of the course, you will have a solid grip on const and its usage in preventing any accidental change of data.

Secure Coding Practices in C++: A Deep Dive into const

Congratulations! Now, we know how to use `const` better than the average C++ developer. Don’t get complacent though. The real work starts now!

We  have two tasks:
* Apply the knowledge!
* Share the knowledge!

The best way to share knowledge and teach people new practices is by [leading by example](https://www.sandordargo.com/blog/2018/05/15/the-only-true-way-educate). 
Using these new techniques consistently will make our colleagues curious, and we can share it with them. You can also go ahead and schedule a knowledge-sharing session where you explain what you learned and initiate a discussion.

# Recap

* Make local, global, and static variables `const` whenever possible to avoid accidental changes in their value and allow the compiler to optimize further.

* Don’t make member variables `const` because it will prevent the compiler from generating special copy assignment functions and benefiting from move semantics.

* Make member functions `const` whenever possible. It helps avoid accidentally changing the object’s state. It also provides some necessary guarantees to the caller.

* Don’t return `const` values and be cautious with `const` pointers and references. Make sure that the object you point to or refer to will still exist when used. In short, avoid dangling pointers and references. But don’t hesitate to use `const` pointers and references in case you think it’s safe and you can spare some costly copies.

* Take `const` parameters whenever you have no intentions to update them. In the case of values, this is mainly informational to the caller. For references and pointers, as in the case of an update, the caller has to deal with the consequences. Even if the compiler doesn’t enforce it, make sure that the function declaration matches the definition even in terms of constness for all the parameters and the return type.

Write code filling the virtues of constness, and you’ll live a calmer life as a developer!

Let’s recap and conclude what we have learned in this course.


Summary

Let’s recap and conclude what we have learned in this course.

Introduction

Arguments using const

Local Variables

Local Members

Functions

Return Types

const Parameters

const and Smart Pointers

Rvalue References

Summary

Summary