void start()

in include/unifex/stop_immediately.hpp [258:294]
35 lines of code
2 McCabe index (conditional complexity)

        void start() noexcept {
          auto stopToken = get_stop_token(receiver_);
          if (stopToken.stop_requested()) {
              unifex::set_done(std::move(receiver_));
              return;
          }

          static_assert(
            std::is_same_v<decltype(stopToken), ST>);

          UNIFEX_TRY {
            stream_.nextOp_.construct_with([&] {
              return unifex::connect(
                next(stream_.source_),
                next_receiver{stream_});
            });
            stream_.nextReceiver_ = &concreteReceiver_;
            stream_.state_.store(
              state::source_next_active, std::memory_order_relaxed);
            UNIFEX_TRY {
              stopCallback_.construct(
                std::move(stopToken),
                cancel_next_callback{stream_});
              unifex::start(stream_.nextOp_.get());
            } UNIFEX_CATCH (...) {
              stream_.nextReceiver_ = nullptr;
              stream_.nextOp_.destruct();
              stream_.state_.store(
                state::source_next_completed, std::memory_order_relaxed);
              unifex::set_error(std::move(receiver_), std::current_exception());
            }
          } UNIFEX_CATCH (...) {
            stream_.state_.store(
              state::source_next_completed, std::memory_order_relaxed);
            unifex::set_error(std::move(receiver_), std::current_exception());
          }
        }