Function scn_do_execute

imperative/src/impl/ops/elemwise.cpp:178–191

        set_megdnn_opr(std::move(opr));
    }
    void scn_do_execute() override {
        auto to_dnnnd = [&](auto* var) { return var->dev_tensor().as_megdnn(); };
        megdnn::TensorNDArray inputs_dnnnd;
        for (auto* input : input()) {
            inputs_dnnnd.push_back(to_dnnnd(input));
        }
        mgb_assert(
                input(m_param.inplace_index)
                        ->contain_flag(VarNode::Flag::NO_SYS_MEM_ALLOC),
                "ForceInplaceElemwise cannot be applied in internal tensor");
        auto* out_dest = output(0);
        auto* opr = static_cast<megdnn::Elemwise*>(megdnn_opr());
        opr->exec(std::move(inputs_dnnnd), to_dnnnd(out_dest));
    }
    void init_output_static_infer_desc() override {
        using namespace cg::static_infer;