Demystifying CRTP in C++: What, Why, and How
- alex d
- Oct 27, 2024
- 2 min read
Hello, C++ enthusiasts! 🎉
After a long stretch of planning and work, I’m thrilled to share my latest video with you, where I dive into one of the more unique patterns in C++: the Curiously Recurring Template Pattern (CRTP).
This pattern has a bit of a mysterious name, and it often leaves developers scratching their heads – I know, because I heard the same question over and over at CppCon!
In this post (and the video), I'll address the most common questions:
What exactly is CRTP?
Why should we use it?
And, most importantly, how do we implement it?
Let’s break it down.
What is CRTP?
The Curiously Recurring Template Pattern is a form of static polymorphism where a derived class is templated on itself and inherits from this template. It’s a design pattern that gives us powerful flexibility, especially when we want to avoid runtime polymorphism (i.e., virtual functions).
Think of it like giving our code a blueprint to optimize certain behaviors at compile time, instead of relying on traditional inheritance-based polymorphism.
Why Use CRTP?
CRTP allows for efficient code reuse, enforces certain behaviors in derived classes, and helps in scenarios where performance is critical. Some common use cases include:
Implementing functionality that should only be accessible by derived classes.
Avoiding the overhead of virtual tables by using static polymorphism.
Adding behavior or properties to derived classes without impacting runtime performance.
Watch the Full Walkthrough!
CRTP can feel a little intimidating at first, but it’s an incredibly powerful pattern once you get the hang of it. I hope this video makes things clearer and helps you feel more confident applying CRTP in your own projects!
Let me know what you think – happy coding! 🚀