#include <iostream>
#include <chrono>
#include <future>
 
using std::cout;
using std::cin;
using std::endl;
 
int bar() { return 42; }
 
int main()
{
    auto s2 = std::chrono::steady_clock::now();
    auto sh_ptr1 = std::make_shared<std::packaged_task<int()> >(bar);
    auto e2 = std::chrono::steady_clock::now();
 
    auto s1 = std::chrono::steady_clock::now();
    std::packaged_task<int()> pt1(bar);
    auto e1 = std::chrono::steady_clock::now();
 
    auto first = std::chrono::duration_cast<std::chrono::nanoseconds>(e1-s1);
    auto second = std::chrono::duration_cast<std::chrono::nanoseconds>(e2-s2);
 
    cout << "Regular: " << first.count() << endl
         << "Make shared: " << second.count() << endl;
 
    pt1();
    (*sh_ptr1)();
 
    cout << "As you can see, both are working correctly: " 
         << pt1.get_future().get() << " & " 
         << sh_ptr1->get_future().get() << endl;
 
    return 0;
}

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