Function GxB_Matrix_select_FC64 

pub unsafe extern "C" fn GxB_Matrix_select_FC64(
    C: GrB_Matrix,
    Mask: GrB_Matrix,
    accum: GrB_BinaryOp,
    op: GrB_IndexUnaryOp,
    A: GrB_Matrix,
    y: GxB_FC64_t,
    desc: GrB_Descriptor,
) -> GrB_Info