What is the difference between std::async and std::thread?

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Accepted Answer

**std::async** — run a function asynchronously and get a future. **std::thread** — low-level thread management. ```cpp #include #include int compute(int x) { return x * x; } // std::async — returns future auto fut = std::async(std::launch::async, compute, 42); int result = fut.get(); // Blocks until done // std::thread — manual management int result2; std::thread t([&]{ result2 = compute(42); }); t.join(); // Async launch policies std::async(std::launch::async, func); // Must run async std::async(std::launch::deferred, func); // Run on get() std::async(std::launch::async | std::launch::deferred, func); // Either ``` **Comparison:** - std::async — higher-level, returns future. - std::thread — lower-level, more control. - std::async may reuse thread pool. - std::thread always creates a new thread.

C++: What is the difference between std::async and std::thread?