Change Details

This does not apply on it's own see test plan. Removing the `std::function` does not improve performance by much: (D4730) ``` async cost: enqueueing: 337ms work done: 337ms total: 343ms async round-trip: total: 814ms ``` (D4730 + D4812 + this patch) ``` async cost: enqueueing: 331ms work done: 331ms total: 335ms async round-trip: total: 813ms ``` I achieved "removing the std::function" by templating the `SharedState` not on the result but on the function. The `Future` does not hold a pointer to the SharedState anymore (The Future would have to be templated on the function as well) but to a subobject of it (the `Receiver`) which is templated only on the result type. I think spliting the `SharedState` in a comunication and a ownership part is the way to go. (single responsibility) What do you think?

This does not apply on it's own see test plan. The Receiver Is responsible for comunication with the receiving thread. - Storing the return value. - Synchronisation - Notifying if the receiving thread is waiting. - Handle cancelation. The SharedState does contain all data used to execute the task. - Store the function and the Receiver. The Future (the receiving thread) does only need a pointer to the receiver. The PackagedTask (the executing therad) needs a pointer to the whole SharedState since it needs to know which function to execute and were to save it. The Function is not restricted to std::function anymore. Move only function become possible (see test).

This does not apply on it's own see test plan. Removing the `std::function` does not improve performance by much: (D4730) ``` async cost: enqueueing: 337ms work done: 337ms total: 343ms async round-trip: total: 814ms ``` (D4730 + D4812 + this patch) ``` async cost:The Receiver Is responsible for comunication with the receiving thread. enqueueing: 331ms - Storing the return value. work done: 331ms - Synchronisation total: 335ms - Notifying if the receiving thread is waiting. async round-trip: - Handle cancelation. The SharedState does contain all data used to execute the task. total: 813ms - Store the function and the Receiver. The Future (the receiving thread) does only need a pointer to the receiver. ```The PackagedTask (the executing therad) needs a pointer to the whole SharedState since it needs to know which function to execute and were to save it. I achieved "removing the std::function" by templating the `SharedState` not on the result but on the function. The `Future` does not hold a pointer to the SharedState anymore (The Future would have to be templated on the function as well) but to a subobject of it (the `Receiver`) which is templated only on the result type. I think spliting the `SharedState` in a comunication and a ownership part is the way to goThe Function is not restricted to std::function anymore. (single responsibility) What do you think?Move only function become possible (see test).