* Alternatively, you can use a custom stream that reads directly from e.g.
* a file or a network socket.
*/
-pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize);
+pb_istream_t pb_istream_from_buffer(const uint8_t *buf, size_t bufsize);
/* Function to read from a pb_istream_t. You can use this if you need to
* read some custom header data, or to read data in field callbacks.