What is type erasure in C++17?

What is type erasure in C++17?

Type erasure is a programming technique that allows you to hide the specific type of an object while still being able to use it. In C++17, this is often achieved using std::any, std::function, or templates.

Can you give me an example of type erasure using std::function?

Sure! Here's a simple example:

#include <iostream>
#include <functional>

void callFunction(std::function<void()> func) {
    func();
}

int main() {
    int x = 10;
    callFunction([x]() { std::cout << "Value of x: " << x << std::endl; });
    return 0;
}

In this example, the lambda captures x and is passed to callFunction, demonstrating type erasure.

What are the benefits of using type erasure?

The benefits include increased flexibility, the ability to write more generic code, and the ability to work with different types without knowing their specifics at compile time.

Are there any downsides to using type erasure?

Yes, some downsides include potential performance overhead due to dynamic type checks and the loss of type information, which can lead to runtime errors if not handled carefully.