Class __spawn_future_impl

include/stdexec/__detail/__spawn_future.hpp:731–774

    };

    struct __spawn_future_impl : __sexpr_defaults
    {
      // __data_of<_Sender> is a unique_ptr specialization
      template <class _Sender>
      using __unique_ptr_t = __data_of<std::remove_cvref_t<_Sender>>;

      template <class _Sender>
      using __spawn_future_state_t = __unique_ptr_t<_Sender>::element_type;

      template <class _Sender, class _Env>
      using __completions_t = __spawn_future_state_t<_Sender>::template __completions_t<_Env>;

      template <class _Sender, class _Env>
      static consteval auto __get_completion_signatures()  //
        -> __completions_t<_Sender, _Env>
      {
        return {};
      };

      static constexpr auto __get_state =
        []<class _Sender, class _Receiver>(_Sender&& __sndr, _Receiver __rcvr) noexcept /* TODO */
        -> __future_operation<std::remove_cvref_t<_Sender>, _Receiver>
      {
        auto& [_, __future] = __sndr;
        return {std::move(__future), std::move(__rcvr)};
      };

      static constexpr auto __start = [](auto& __state) noexcept
      {
        constexpr bool __non_throwing = noexcept(__state.__run());

        STDEXEC_TRY
        {
          __state.__run();
        }
        STDEXEC_CATCH_ALL
        {
          if constexpr (!__non_throwing)
          {
            STDEXEC::set_error(std::move(__state.__rcvr_), std::current_exception());
          }
        }
      };
    };
  }  // namespace __spawn_future

  using __spawn_future::spawn_future_t;