add example of how to do length calculation
diff --git a/example.c b/example.c
index 02345ec..9e51198 100644
--- a/example.c
+++ b/example.c
@@ -147,8 +147,13 @@
  * @c Buffer must be big enough to hold the output. If it is not @ref
  * NULLUsefulBufC will be returned. @ref NULLUsefulBufC will be
  * returned for any other encoding errors.
+ *
+ * This can be called with @c Buffer set to @ref SizeCalculateUsefulBuf
+ * in which case the size of the encoded engine will be calculated, but no
+ * actual encoding will be done. The size is in @c .len of the returned
+ * UsefulBufC.
  */
-UsefulBufC EncodeEngineDefiniteLength(const CarEngine *pEngine, UsefulBuf Buffer)
+UsefulBufC EncodeEngine(const CarEngine *pEngine, UsefulBuf Buffer)
 {
    /* Set up the encoding context with the output buffer */
     QCBOREncodeContext EncodeCtx;
@@ -333,7 +338,7 @@
    EngineInit(&InitialEngine);
 
    /* Encode the engine structure. */
-   EncodedEngine = EncodeEngineDefiniteLength(&InitialEngine, EngineBuffer);
+   EncodedEngine = EncodeEngine(&InitialEngine, EngineBuffer);
    if(UsefulBuf_IsNULLC(EncodedEngine)) {
       printf("Engine encode failed\n");
       goto Done;
@@ -353,6 +358,24 @@
       printf("Example: Spiffy Engine Decode comparison fail\n");
    }
 
+
+   /* Further example of how to calculate the encoded size, then allocate */
+   UsefulBufC EncodedEngineSize;
+   EncodedEngineSize = EncodeEngine(&InitialEngine, SizeCalculateUsefulBuf);
+   if(UsefulBuf_IsNULLC(EncodedEngine)) {
+      printf("Engine encode size calculation failed\n");
+      goto Done;
+   }
+   /* Here malloc could be called to allocate a buffer. Then
+    * EncodeEngine() can be called a second time to actually
+    * encode. (The actual code is not live here to avoid a
+    * dependency on malloc()).
+    *   UsefulBuf  MallocedBuffer;
+    *   MallocedBuffer.len = EncodedEngineSize.len;
+    *   MallocedBuffer.ptr = malloc(EncodedEngineSize.len);
+    *   EncodedEngine = EncodeEngine(&InitialEngine, MallocedBuffer);
+    */
+
 Done:
    printf("\n");