Depsgraph: Add named constant with number of node types

source/blender/depsgraph/intern/depsgraph_types.h

@@ -124,6 +124,9 @@ typedef enum eDepsNode_Type {
 	DEG_NODE_TYPE_SHADING,
 	/* Cache Component */
 	DEG_NODE_TYPE_CACHE,
+
+	/* Total number of meaningful node types. */
+	NUM_DEG_NODE_TYPES,
 } eDepsNode_Type;
 
 /* Identifiers for common operations (as an enum). */

source/blender/depsgraph/intern/eval/deg_eval_flush.cc

@@ -176,6 +176,7 @@ void deg_graph_flush_updates(Main *bmain, Depsgraph *graph)
 						case DEG_NODE_TYPE_TIMESOURCE:
 						case DEG_NODE_TYPE_ID_REF:
 						case DEG_NODE_TYPE_SEQUENCER:
+						case NUM_DEG_NODE_TYPES:
 							/* Ignore, does not translate to object component. */
 							BLI_assert(!"This should never happen!");
 							break;