Construct one std::atomic_future object from another,
so that both the source and the copy refer to the asynchronous result
associated with the source std::atomic_future object, if any.
atomic_future(atomic_future const& other);
Constructs a new std::atomic_future instance.
The asynchronous result associated with other
prior to the invocation of the constructor is associated with the
newly-constructed std::atomic_future object
and other.
Nothing.
#include <future>