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

# What about returning `const` references?
Sometimes, newer developers return `const` references just to be symmetric with the well-known best practice of taking class type arguments by `const` reference. However, this can cause a few issues.

## What is the problem?

The problem with returning `const` references is that the returned object has to outlive the caller. At least it has to live as long as the caller exists.

```
void f() {
  MyObject o;
  const auto& aRef = o.getSomethingConstRef();
  aRef.doSomething(); // will this work?
}
```
Will that work?
It depends.

If `MyObject::getSomethingConstRef()` returns a `const` reference of a local variable, it will not work. It is because local variables are destroyed immediately when the program moves beyond the scope of the function.

Learn about the const returning by references.


Returning const References

Learn about the const returning by references.

Introduction

Arguments using const

Local Variables

Local Members

Functions

Return Types

const Parameters

const and Smart Pointers

Rvalue References

Summary

Returning const References

What about returning `const` references?

What is the problem?

Returning const References

What about returning const references?

What is the problem?

What about returning `const` references?