PackagedTask.cpp

/**
 * \file  PackagedTask.cpp
 * \brief
 *
 * \see   http://en.cppreference.com/w/cpp/thread/packaged_task
 * \review
 */


#include <StdStream/StdStream.h>
#include <StdTest/StdTest.h>
#include <Stl.h>
//--------------------------------------------------------------------------------------------------
// unique function to avoid disambiguating the std::pow overload set
int f(int x, int y) { return std::pow(x,y); }
//--------------------------------------------------------------------------------------------------
void task_lambda()
{
    std::packaged_task<int(int,int)> task([](int a, int b) { return std::pow(a, b); });
    std::future<int> result = task.get_future();

    task(2, 9);

    std::cout << "task_lambda:\t" << result.get() << '\n';
}
//--------------------------------------------------------------------------------------------------
void task_bind()
{
    std::packaged_task<int()> task(std::bind(f, 2, 11));
    std::future<int> result = task.get_future();

    task();

    std::cout << "task_bind:\t" << result.get() << '\n';
}
//--------------------------------------------------------------------------------------------------
void task_thread()
{
    /* the following does not work */
    //std::packaged_task<int(int,int)> task(f);

    std::packaged_task<int(int,int)> task([](int a, int b) { return f(a,b); });
    std::future<int> result = task.get_future();

    std::thread task_td(std::move(task), 2, 10);
    task_td.join();

    std::cout << "task_thread:\t" << result.get() << '\n';
}
//--------------------------------------------------------------------------------------------------
int main(int, char **)
{
    task_lambda();
    task_bind();
    task_thread();

    return 0;
}
//--------------------------------------------------------------------------------------------------