What are some use cases for variadic templates in C++?

What are some use cases for variadic templates in C++?

Variadic templates in C++ allow functions and classes to accept any number of template parameters. They are useful for creating flexible and reusable code. Some common use cases include implementing type-safe functions, creating tuple-like structures, and building generic data structures.

Can you give me an example of a variadic template function?

Sure! Here's a simple example of a variadic template function that calculates the sum of its arguments:

template<typename... Args>
auto sum(Args... args) {
    return (args + ...);
}

You can call it like this: sum(1, 2, 3, 4); which will return 10.

What about using variadic templates with classes?

Great question! You can use variadic templates to create classes that can accept multiple types. For example, a Logger class could take any number of message types and log them:

template<typename... Args>
class Logger {
public:
    void log(Args... args) {
        // Log each argument
    }
};

Are there any performance considerations with variadic templates?

Yes, while variadic templates provide flexibility, they can lead to increased compile times and larger binary sizes due to template instantiation. It's important to balance flexibility with performance needs.