What are futures in C++ and how do they handle concurrency?

Can you explain what futures are in C++?

Futures in C++ are a way to retrieve values from asynchronous operations. They allow you to run tasks concurrently and get results later.

How do futures help with concurrency?

Futures enable you to run multiple tasks at the same time without blocking the main thread, improving efficiency and responsiveness.

Can you give an example of using futures in a C++ program?

Sure! You can use std::async to launch a task asynchronously and get a future object to retrieve the result later.

What happens if a future is not ready when I try to access it?

If you try to access a future that isn't ready, it will block until the result is available, or throw an exception if the task failed.