What are some examples of C++ coroutines?

Can you give me some examples of C++ coroutines?

Sure! C++ coroutines allow you to write asynchronous code more easily. For example, you can use co_await to pause execution until a task is complete.

How do I implement a simple coroutine in C++?

You can implement a simple coroutine by defining a function with the co_await keyword. Here's a basic example:

#include <iostream>
#include <coroutine>

struct SimpleCoroutine {
    struct promise_type {
        SimpleCoroutine get_return_object() { return {}; }
        std::suspend_never initial_suspend() { return {}; }
        std::suspend_never final_suspend() noexcept { return {}; }
        void unhandled_exception() {}
        void return_void() {}
    };
};

SimpleCoroutine example() {
    std::cout << "Coroutine started" << std::endl;
    co_await std::suspend_always();
    std::cout << "Coroutine resumed" << std::endl;
}

What are the benefits of using coroutines over traditional threading?

Coroutines are generally lighter than threads, allowing for more efficient context switching. They also simplify asynchronous programming by avoiding callback hell.

Can you show me a more complex example of using coroutines?

Absolutely! Here's a more complex example that demonstrates a coroutine fetching data asynchronously:

#include <iostream>
#include <coroutine>
#include <future>

struct AsyncFetch {
    struct promise_type {
        AsyncFetch get_return_object() { return {}; }
        std::suspend_always initial_suspend() { return {}; }
        std::suspend_always final_suspend() noexcept { return {}; }
        void unhandled_exception() {}
        void return_void() {}
    };
};

AsyncFetch fetchData() {
    std::cout << "Fetching data..." << std::endl;
    co_await std::suspend_always(); // Simulate async wait
    std::cout << "Data fetched!" << std::endl;
}