How do I write requires clauses?

In C++, requires clauses are used in concepts to constrain template parameters. They allow you to specify that a template argument must satisfy certain conditions, thereby enabling more precise type checking and more readable code.

Here's an example of how to use requires clauses in a template function:


    template
    requires std::integral
    T add(T a, T b) {
        return a + b;
    }

In this example, the add function can only accept integral types (like int or long). If a non-integral type is provided, a compilation error will occur.