example2_deferred_execution.cpp

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#include <iostream>
#include <future>
#include <thread>
#include <chrono>

int longComputation(int x) {
    std::this_thread::sleep_for(std::chrono::seconds(3));  // Simulate a long computation
    return x * x;
}

int main() {
    std::cout << "Starting async task with deferred execution..." << std::endl;

    // Start the longComputation function with deferred execution
    std::future<int> result = std::async(std::launch::deferred, longComputation, 10);

    std::cout << "Doing other work in main thread..." << std::endl;

    // The function is not executed until result.get() is called
    int value = result.get();

    std::cout << "Result from deferred task: " << value << std::endl;

    return 0;
}