RAII & Smart Pointers

What you'll walk away with

Explain the type, lifetime, and runtime behavior of RAII & Smart Pointers
Use warnings and sanitizers to test failure cases
Write modern and safer C++

Understand RAII & Smart Pointers as a contract about object lifetime, ownership, borrowing, invalidation, and exception safety—not merely syntax. Prefer RAII value types and smart pointers over raw owning new and delete so dangling access and double release are prevented by design.

Build a Complete Mental Model

Apply It in Modern C++

Build an original RAII & Smart Pointers example with `-std=c++23 -Wall -Wextra -Wpedantic` and test empty, boundary, invalid, and failure cases. Run lifetime-sensitive code under AddressSanitizer and UndefinedBehaviorSanitizer.

After This Lesson

Explain the ownership and lifetime contract
Build in C++23 mode with no warnings
Run a boundary or failure test under a sanitizer

cpp

#include <iostream>
#include <memory>

struct Resource {
    ~Resource() { std::cout << "released\n"; }
};

int main() {
    auto resource = std::make_unique<Resource>();
    std::cout << "owned\n";
}

You should see

owned
released

Try It Yourself

Memory and Safety Warning

Assuming one correct output proves lifetime, bounds, ownership, and undefined behavior are all correct.

C++ Core Guidelines — Standard C++ Foundation

Easy traps

Assuming one correct output proves lifetime, bounds, ownership, and undefined behavior are all correct.
Assuming a raw pointer or iterator remains valid after its owning container or resource changes.

Hands-on Exercise

You'll know it worked when: owned released