Function xcb::ffi::xkb::xcb_xkb_set_names_values_groups_length

pub unsafe extern "C" fn xcb_xkb_set_names_values_groups_length(
    R: *const xcb_xkb_set_names_request_t, 
    S: *const xcb_xkb_set_names_values_t
) -> c_int