.. _simple_promise: ============== simple_promise ============== -------------------------- A ``simple_promise`` is the simplest "returning" promise. The internal state maintains an ``optional`` which is set by the coroutine body. This allows a [coroutine Type](#Coroutine-Types) to pull out the return type and provide it to the caller. ``simple_promise`` satisfies the ``Returnable`` concept. The coroutine key words available are ``co_return (ARG)`` where T is constructible from ``ARG``, ``co_return (std::nullopt_t)`` in the case the promise cannot be fulfilled and ``co_await (AwaitableProxy)`` for suspension. -------------------------- .. doxygenclass:: zab::simple_promise :members: :protected-members: :undoc-members: