Function GxB_Matrix_pack_BitmapC 

pub unsafe extern "C" fn GxB_Matrix_pack_BitmapC(
    A: GrB_Matrix,
    Ab: *mut *mut i8,
    Ax: *mut *mut c_void,
    Ab_size: GrB_Index,
    Ax_size: GrB_Index,
    iso: bool,
    nvals: GrB_Index,
    desc: GrB_Descriptor,
) -> GrB_Info