Type Definition alsa_sys::snd_hctl_callback_t

type snd_hctl_callback_t = Option<unsafe extern "C" fn(hctl: *mut snd_hctl_t, mask: c_uint, elem: *mut snd_hctl_elem_t) -> c_int>;

\brief HCTL callback function \param hctl HCTL handle \param mask event mask \param elem related HCTL element (if any) \return 0 on success otherwise a negative error code