Add some example service requests to C++ ROS2 example

examples/c++-ros2-dataflow/node-rust-api/main.cc

@@ -29,7 +29,15 @@ int main()
     std::default_random_engine gen(dev());
     std::uniform_real_distribution<> dist(0., 1.);
 
+    auto service_qos = qos_default();
+    service_qos.reliable = true;
+    service_qos.max_blocking_time = 0.1;
+    service_qos.keep_last = 1;
+    auto add_two_ints = node->create_client_example_interfaces_AddTwoInts("/", "add_two_ints", service_qos, merged_events);
+    add_two_ints->wait_for_service(node);
+
     auto received_ticks = 0;
+    auto responses_received = 0;
 
     for (int i = 0; i < 1000; i++)
     {
@@ -56,6 +64,9 @@ int main()
                     .linear = {.x = dist(gen) + 1, .y = 0, .z = 0},
                     .angular = {.x = 0, .y = 0, .z = (dist(gen) - 0.5) * 5.0}};
                 vel_publisher->publish(twist);
+
+                example_interfaces::AddTwoInts_Request request = {.a = 4, .b = 5};
+                add_two_ints->send_request(request);
             }
             else
             {
@@ -72,12 +83,22 @@ int main()
             auto pose = pose_subscription->downcast(std::move(event));
             std::cout << "Received pose x:" << pose.x << ", y:" << pose.y << std::endl;
         }
+        else if (add_two_ints->matches(event))
+        {
+            auto response = add_two_ints->downcast(std::move(event));
+            assert(response.sum == 9);
+            std::cout << "Received correct sum response from add_two_ints" << std::endl;
+            responses_received += 1;
+        }
         else
         {
             std::cout << "received unexpected event" << std::endl;
         }
     }
 
+    std::cout << "Received " << responses_received << " service responses" << std::endl;
+    assert(responses_received > 0);
+
     // try to access a constant for testing
     assert((sensor_msgs::const_NavSatStatus_STATUS_NO_FIX() == -1));