class WFTaskFactory
{
    ...
public:
    template<class FUNC, class... ARGS>
    static WFGoTask *create_go_task(const std::string& queue_name,
                                    FUNC&& func, ARGS&&... args);
};

#include <stdio.h>
#include <utility>
#include "workflow/WFTaskFactory.h"
#include "workflow/WFFacilities.h"

void add(int a, int b, int& res)
{
    res = a + b;
}

int main(void)
{
    WFFacilities::WaitGroup wait_group(1);
    int a = 1;
    int b = 1;
    int res;

    WFGoTask *task = WFTaskFactory::create_go_task("test", add, a, b, std::ref(res));
    task->set_callback([&](WFGoTask *task) {
        printf("%d + %d = %d\n", a, b, res);
        wait_group.done();
    });
 
    task->start();
    wait_group.wait();
    return 0;
}