Function GrB_vxm 

pub unsafe extern "C" fn GrB_vxm(
    w: GrB_Vector,
    mask: GrB_Vector,
    accum: GrB_BinaryOp,
    semiring: GrB_Semiring,
    u: GrB_Vector,
    A: GrB_Matrix,
    desc: GrB_Descriptor,
) -> GrB_Info