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Код

namespace Async {

template< class Res >
void async_p( std::function< Res() > worker, std::function< void(Res) > waiter
            , typename std::enable_if< ! std::is_void< Res >::value >::type * p = 0 )
{
    waiter( worker() );
}

template< class Res >
void async_p( std::function< void() > worker, std::function< void() > waiter
            , typename std::enable_if< std::is_void< Res >::value >::type * p = 0 )
{
    worker();
    waiter();
}

template< class Waiter, class ... Args >
std::future< void > run( Waiter bound_waiter, Args ... args )
{
    typedef decltype( std::bind( args... )() ) Worker_Res;
    std::function< Worker_Res() > worker = std::bind( args... );
    return std::async( async_p< Worker_Res >, worker, bound_waiter, nullptr );
}

template< class Worker_Res, class Waiter, class ... Args >
std::future< void > run( void (Waiter::*waiter_f)(Worker_Res), Waiter waiter, Args ... args )
{
    std::function< Worker_Res() > worker = std::bind( args... );
    std::function< void(Worker_Res) > bound_waiter =
        std::bind( waiter_f, waiter, std::placeholders::_1 );
    return run( bound_waiter, args... );
}

template< class Waiter, class ... Args >
std::future< void > run( void (Waiter::*waiter_f)(), Waiter waiter, Args ... args )
{
    std::function< void() > worker = std::bind( args... );
    std::function< void() > bound_waiter = std::bind( waiter_f, waiter );
    return run( bound_waiter, args... );
}

} // namespace Async {

using std::cout;
using std::endl;

class Worker {
public:
    std::string work( const std::string & str, int x ) {
        cout << "Worker::work( " << str << ", " << x << " );" << endl;
        return str;
    }
};

class Waiter {
public:
    void onFinish( const std::string & str ) {
        cout << "Waiter::onFinish( " << str << " );" << endl;
    }
    void onFinish_v() {
        cout << "Waiter::onFinish( void );" << endl;
    }
};

void onFinish( const std::string & str ) {
    cout << "::onFinish( " << str << " );" << endl;
}

void work() {
    cout << "__work__( " << endl;
}

void onFinish_v() {
    cout << "::onFinish( void  );" << endl;
}


Worker worker;
Waiter waiter;

int main()
{
    auto f_v = Async::run( &Waiter::onFinish_v, waiter, work );
    auto f_x = Async::run( onFinish_v, work );
    auto f_0 = Async::run( onFinish, &Worker::work, worker, "str for worker 0", 42 );
    auto f_1 = Async::run( &Waiter::onFinish, waiter, &Worker::work, worker, "str for worker 1", 421 );
   
    f_1.wait();
    f_0.wait();
    f_x.wait();
    f_v.wait();
}