Function cast

imperative/python/src/ops.cpp:254–260

        return false;
    }
    static PyObject* cast(const T& value) {
        auto v = static_cast<std::underlying_type_t<T>>(value);
        mgb_assert(v <= EnumTrait<T>::max);
        PyObject* obj = pyobj_insts[v];
        Py_INCREF(obj);
        return obj;
    }
};

template <typename T>