What are C++20 concepts and how do I use them?

What are C++20 concepts and how do I use them?

C++20 concepts are a way to specify template requirements more clearly. They allow you to define constraints on template parameters.

Can you give me an example of a concept in C++20?

Sure! A simple example is the 'Integral' concept, which checks if a type is an integer type. You can define it like this:

template<typename T>
concept Integral = std::is_integral_v<T>;

How do I apply concepts in a template function?

You can use concepts to constrain template parameters. For example:

template<Integral T>
T add(T a, T b) {
    return a + b;
}
``` This ensures that only integral types can be passed to the `add` function.

What are the benefits of using concepts over traditional SFINAE?

Concepts provide clearer error messages and improve code readability. They make it easier to understand the requirements of templates at a glance.