Implement stubs for new 'rmw_count_*' functions (ros2#100)

Signed-off-by: Simon Hoinkis <[email protected]>

Author: mossmaurice-apexai

rmw_iceoryx_cpp/src/rmw_count.cpp

@@ -84,6 +84,46 @@ rmw_count_subscribers(
   return RMW_RET_OK;
 }
 
+rmw_ret_t
+rmw_count_services(
+  const rmw_node_t * node,
+  const char * service_name,
+  size_t * count)
+{
+  RCUTILS_CHECK_ARGUMENT_FOR_NULL(node, RMW_RET_ERROR);
+  RCUTILS_CHECK_ARGUMENT_FOR_NULL(service_name, RMW_RET_ERROR);
+  RCUTILS_CHECK_ARGUMENT_FOR_NULL(count, RMW_RET_ERROR);
+
+  RMW_CHECK_TYPE_IDENTIFIERS_MATCH(
+    rmw_count_subscribers
+    : node, node->implementation_identifier,
+    rmw_get_implementation_identifier(), return RMW_RET_ERROR);
+
+  /// @todo There is no API to find out which 'ServiceDescription' is offered by which node
+  RMW_SET_ERROR_MSG("rmw_count_services is not supported in iceoryx");
+  return RMW_RET_UNSUPPORTED;
+}
+
+rmw_ret_t
+rmw_count_clients(
+  const rmw_node_t * node,
+  const char * service_name,
+  size_t * count)
+{
+  RCUTILS_CHECK_ARGUMENT_FOR_NULL(node, RMW_RET_ERROR);
+  RCUTILS_CHECK_ARGUMENT_FOR_NULL(service_name, RMW_RET_ERROR);
+  RCUTILS_CHECK_ARGUMENT_FOR_NULL(count, RMW_RET_ERROR);
+
+  RMW_CHECK_TYPE_IDENTIFIERS_MATCH(
+    rmw_count_subscribers
+    : node, node->implementation_identifier,
+    rmw_get_implementation_identifier(), return RMW_RET_ERROR);
+
+  /// @todo There is no API to find out which 'ServiceDescription' is offered by which node
+  RMW_SET_ERROR_MSG("rmw_count_clients is not supported in iceoryx");
+  return RMW_RET_UNSUPPORTED;
+}
+
 rmw_ret_t
 rmw_subscription_count_matched_publishers(
   const rmw_subscription_t * subscription,