Const
Automatically call libusb_free_transfer() after callback returns. If this flag is set, it is illegal to call libusb_free_transfer() from your transfer callback, as this will result in a double-free when this flag is acted upon.
Automatically call libusb_free_transfer() after callback returns. If this flag is set, it is illegal to call libusb_free_transfer() from your transfer callback, as this will result in a double-free when this flag is acted upon.