Diff: CANMsg/CANMsg.h

Revision:

0:12fb9cbcabcc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CANMsg/CANMsg.h	Wed Jul 24 20:03:52 2019 +0000
@@ -0,0 +1,67 @@
+#ifndef CANMSG_H
+#define CANMSG_H
+
+/* CAN message container.
+ * Provides "<<" (append) and ">>" (extract) operators to simplyfy
+ * adding/getting data items to/from a CAN message.
+ * Usage is similar to the C++ io-stream operators.
+ * Data length of CAN message is automatically updated when using "<<" or ">>" operators.
+ *
+ * See Wiki page <https://developer.mbed.org/users/hudakz/code/CAN_Hello/> for demo.
+ */
+#include "CAN.h"
+
+class CANMsg : public CANMessage
+{
+public:
+    /** Creates empty CAN message.
+     */
+    CANMsg() :
+        CANMessage(){ }
+
+    /** Creates CAN message with specific content.
+     */
+    CANMsg(int _id, const char *_data, char _len = 8, CANType _type = CANData, CANFormat _format = CANStandard) :
+        CANMessage(_id, _data, _len, _type, _format){ }
+
+    /** Creates CAN remote message.
+     */
+    CANMsg(int _id, CANFormat _format = CANStandard) :
+        CANMessage(_id, _format){ }
+
+    /** Clears CAN message content
+     */
+    void clear(int new_id) {
+        len    = 0;
+        type   = CANData;
+        format = CANStandard;
+        id     = new_id;
+        memset(data, 0, 8);
+    };
+
+    /** Append operator: Appends data (value) to CAN message
+     */
+    template<class T>
+    CANMsg &operator<<(const T val) {
+        MBED_ASSERT(len + sizeof(T) <= 8);
+        //*reinterpret_cast<T*>(&data[len]) = val; // This used to work but now it hangs at run time.
+        memcpy(&data[len], &val, sizeof(T));
+        len += sizeof(T);
+        return *this;
+    }
+
+    /** Extract operator: Extracts data (value) from CAN message
+     */
+    template<class T>
+    CANMsg &operator>>(T& val) {
+        MBED_ASSERT(sizeof(T) <= len);
+        val = *reinterpret_cast<T*>(&data[0]);
+        len -= sizeof(T);
+        memcpy(data, data + sizeof(T), len);
+        return *this;
+    }
+};
+
+#endif // CANMSG_H
+
+