added chunk_from_thing() macro

src/libstrongswan/chunk.h

@@ -88,6 +88,11 @@ void chunk_free(chunk_t *chunk);
  */
 #define chunk_from_buf(str) { str, sizeof(str) }
 
+/**
+ * Initialize a chunk to point to a thing
+ */
+#define chunk_from_thing(thing) chunk_create((char*)&(thing), sizeof(thing))
+
 /**
  * Allocate a chunk on the heap
  */