Function pio_gens 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pio_gens(
    net: *const PioNetwork,
    bus: *mut i64,
    pg: *mut f64,
    pmax: *mut f64,
    pmin: *mut f64,
    in_service: *mut u8,
)

Fill the generator tables (each length pio_n_gens; bus is the 1-based bus id, the same id space as pio_bus_ids). Any pointer may be NULL to skip.