#include "tensorstore/util/future.h"
Future<T> tensorstore::Promise<T>::future() const;

Returns an associated Future, if one can be obtained without affecting the value of result_needed() (which would violate an invariant).

Specifically, this returns a valid Future if there is at least one remaining future reference, or SetResult() or SetReady() has been called.

Otherwise, this returns an null Future.

Dchecks:

!null().