API: Add support for type aliases

[vpp.git] / src / vpp-api / vapi / vapi_common.h

diff --git a/src/vpp-api/vapi/vapi_common.h b/src/vpp-api/vapi/vapi_common.h
index ce64469..7157f0a 100644 (file)
--- a/src/vpp-api/vapi/vapi_common.h
+++ b/src/vpp-api/vapi/vapi_common.h
@@ -52,7 +52,9 @@ typedef enum
   VAPI_WAIT_FOR_READ_WRITE,  /**< wait until a read or write can be done */
 } vapi_wait_mode_e;
 
-typedef int vapi_msg_id_t;
+typedef unsigned int vapi_msg_id_t;
+
+#define VAPI_INVALID_MSG_ID ((vapi_msg_id_t)(~0))
 
 #ifdef __cplusplus
 }