The type of the function object that will be invoked.
The function object which will be executed. This object must support the function call operator with a signature of void(void).
The cancellation token which will control implicit cancellation of the function object. Use cancellation_token::none() if you want the function execute without any possibility of implicit cancellation from a parent task group being canceled.
Any interruption points in the function object will be triggered when the cancellation_token is canceled. The explicit token _Ct will isolate this _Func from parent cancellation if the parent has a different token or no token.