Here are the classes, structs, unions and interfaces with brief descriptions:

Crcl_arguments_t	Hold output of parsing command line arguments
Crcl_client_options_t	Options available for a rcl_client_t
Crcl_client_t	Structure which encapsulates a ROS Client
Crcl_clock_t	Encapsulation of a time source
Crcl_context_t	Encapsulates the non-global state of an init/shutdown cycle
Crcl_duration_t	A duration of time, measured in nanoseconds and its source
Crcl_event_t	Structure which encapsulates a ROS QoS event handle
Crcl_guard_condition_options_t	Options available for a rcl guard condition
Crcl_guard_condition_t	Handle for a rcl guard condition
Crcl_init_options_t	Encapsulation of init options and implementation defined init options
Crcl_jump_callback_info_t	Struct to describe an added callback
Crcl_jump_threshold_t	Describe the prerequisites for calling a time jump callback
Crcl_lexer_lookahead2_t	Track lexical analysis and allow looking ahead 2 lexemes
Crcl_node_options_t	Structure which encapsulates the options for creating a rcl_node_t
Crcl_node_t	Structure which encapsulates a ROS Node
Crcl_publisher_options_t	Options available for a rcl publisher
Crcl_publisher_t	Structure which encapsulates a ROS Publisher
Crcl_remap_t	Hold remapping rules
Crcl_service_options_t	Options available for a rcl service
Crcl_service_t	Structure which encapsulates a ROS Service
Crcl_subscription_options_t	Options available for a rcl subscription
Crcl_subscription_t	Structure which encapsulates a ROS Subscription
Crcl_time_jump_t	Struct to describe a jump in time
Crcl_time_point_t	A single point in time, measured in nanoseconds, the reference point is based on the source
Crcl_timer_t	Structure which encapsulates a ROS Timer
Crcl_wait_set_t	Container for subscription's, guard condition's, etc to be waited on