+/* Memory allocation functions to use. You can define pb_realloc and
+ * pb_free to custom functions if you want. */
+#ifdef PB_ENABLE_MALLOC
+# ifndef pb_realloc
+# define pb_realloc(ptr, size) realloc(ptr, size)
+# endif
+# ifndef pb_free
+# define pb_free(ptr) free(ptr)
+# endif
+#endif
+