Template function for creating a task_handle from a function or functor.
// Supported until C++11 template<typename Func> task_handle<Func> make_task( const Func& f ); // Supported since C++11 template<typename TFunc> task_handle<Func> make_task( TFunc&& f );
Returns:task_handle<Func>(f)
Since C++11, the type Func is obtained by removing reference and const/volatile qualifiers remained after deduction of type TFunc.