*/
struct _pb_istream_t
{
+#ifdef PB_BUFFER_ONLY
+ /* Callback pointer is not used in buffer-only configuration.
+ * Having an int pointer here allows binary compatibility but
+ * gives an error if someone tries to assign callback function.
+ */
+ int *callback;
+#else
bool (*callback)(pb_istream_t *stream, uint8_t *buf, size_t count);
+#endif
+
void *state; /* Free field for use by callback implementation */
size_t bytes_left;