Function GxB_Vector_select 

pub unsafe extern "C" fn GxB_Vector_select(
    w: GrB_Vector,
    mask: GrB_Vector,
    accum: GrB_BinaryOp,
    op: GxB_SelectOp,
    u: GrB_Vector,
    Thunk: GrB_Scalar,
    desc: GrB_Descriptor,
) -> GrB_Info