C++ Foundations·Modern C++ without the folklore

RAII and smart pointers

Let destructors release resources, even when exceptions are thrown.

Intermediate 15 min read Lesson 7 of 300 Challenge included

What you will be able to do

Use unique_ptr by default for heap ownership.
Pass unique_ptr by reference or move it; never copy it.
Do not use shared_ptr to avoid thinking about ownership.

In plain English

RAII ties a resource lifetime to an object lifetime. std::unique_ptr expresses exclusive ownership; std::shared_ptr expresses shared ownership and should be rare. Prefer stack values and containers before reaching for a pointer.

owner.cppC++

#include <memory>
#include <iostream>
#include <string>

struct Lesson {
    std::string title;
};

int main() {
    auto lesson = std::make_unique<Lesson>(Lesson{"Pointers"});
    std::cout << lesson->title << "\n";
    // destroyed automatically at the end of scope
}

Your turn

Own a lesson safely

Medium

Create a unique_ptr to a Lesson with the title "RAII" and print the title.

CPP · starter

Lesson* lesson = new Lesson{"RAII"};

Check your understanding before moving on.

Knowledge checkQuestion 1

Which smart pointer communicates exclusive ownership?

Select an answer to continue

Study tools

Make it yours.

Keep a private note for this lesson, then turn the key ideas into flashcards you can revisit.

Sign in to save notes and flashcards.Both are private to your account and stay with your progress.

Finished reading?

Lock in what you just learned.

Mark this lesson complete to save your place and move one step closer to the certificate.

Next: The standard library (STL)

Lesson 7 of 300 · 0% of course