Le 15/04/12 18:57, Master a écrit :
Hello all again . i have couple of questions again which i would appreciate any kind of help and answer, my first question is about packaged_task and how we can use it , i mean i tried using packaged_task with functions , with parameters , and i got errors doing it . so do we always have to use class or stcucts in order for us to use packaged_task ? Hi, The current implementation of packaged_task are nullary, no arguments are allowed.
template<typename R>
class packaged_task {
// execution
void operator()();
}
Waiting for
template
how can i send some arguments to a function when im trying to make a package out of ? Have you tried boost::bind?
can someone show me a simple sample of using Promise in threading ? i mean i already know about future , whats the need for Promise ? !
Promise is the on of the basic class of the Boost.Thread/Futures design. In order to have a future you need a promise, a way to provide a value. packaged_task encapsulates a function with a promise and a future. When the functions ends the result is set on the promise so that you could retrieve it using the associated future. Bat see http://www.justsoftwaresolutions.co.uk/threading/multithreading-in-c++0x-par... for an example. for better explanation and a concrete example. Best, Vicente