Method cast

imperative/python/src/ops.cpp:501–518

    return true;
}
handle type_caster<OpDef>::cast(const OpDef& op, return_value_policy, handle) {
    if (auto* pyop = op.try_cast_final<GenericPyOp>()) {
        return object(pyop->obj).release();
    }
    PyTypeObject* pytype;
    auto& c2p = PyOp(OpDef)::ctype2pytype;
    auto&& iter = c2p.find(op.dyn_typeinfo());
    if (iter != c2p.end()) {  // FIXME: should always meet this condition
        pytype = iter->second;
    } else {  // which means unregistered op type, jsut make it as an opaque op type
        // currently, only OprAttr goes into this branch
        pytype = &PyOpType(OpDef);
    }
    PyObject* obj = pytype->tp_alloc(pytype, 0);
    mgb_assert(PyObject_TypeCheck(obj, &PyOpType(OpDef)));
    reinterpret_cast<PyOp(OpDef)*>(obj)->op = const_cast<OpDef&>(op).shared_from_this();
    return py::handle(obj);
}

#define ENUM_CASTER_IMPL(T)                                                    \
    bool type_caster<T>::load(handle src, bool) {                              \