/* Weak references objects for Python. */ #ifndef Py_WEAKREFOBJECT_H#define Py_WEAKREFOBJECT_H#ifdef __cplusplusextern "C" {#endif  typedef struct _PyWeakReference PyWeakReference; /* PyWeakReference is the base struct for the Python ReferenceType, ProxyType, * and CallableProxyType. */struct _PyWeakReference {    PyObject_HEAD     /* The object to which this is a weak reference, or Py_None if none.     * Note that this is a stealth reference:  wr_object's refcount is     * not incremented to reflect this pointer.     */    PyObject *wr_object;     /* A callable to invoke when wr_object dies, or NULL if none. */    PyObject *wr_callback;     /* A cache for wr_object's hash code.  As usual for hashes, this is -1     * if the hash code isn't known yet.     */    long hash;     /* If wr_object is weakly referenced, wr_object has a doubly-linked NULL-     * terminated list of weak references to it.  These are the list pointers.     * If wr_object goes away, wr_object is set to Py_None, and these pointers     * have no meaning then.     */    PyWeakReference *wr_prev;    PyWeakReference *wr_next;}; PyAPI_DATA(PyTypeObject) _PyWeakref_RefType;PyAPI_DATA(PyTypeObject) _PyWeakref_ProxyType;PyAPI_DATA(PyTypeObject) _PyWeakref_CallableProxyType; #define PyWeakref_CheckRef(op) PyObject_TypeCheck(op, &_PyWeakref_RefType)#define PyWeakref_CheckRefExact(op) \        ((op)->ob_type == &_PyWeakref_RefType)#define PyWeakref_CheckProxy(op) \        (((op)->ob_type == &_PyWeakref_ProxyType) || \         ((op)->ob_type == &_PyWeakref_CallableProxyType)) /* This macro calls PyWeakref_CheckRef() last since that can involve a   function call; this makes it more likely that the function call   will be avoided. */#define PyWeakref_Check(op) \        (PyWeakref_CheckRef(op) || PyWeakref_CheckProxy(op))  PyAPI_FUNC(PyObject *) PyWeakref_NewRef(PyObject *ob,                                              PyObject *callback);PyAPI_FUNC(PyObject *) PyWeakref_NewProxy(PyObject *ob,                                                PyObject *callback);PyAPI_FUNC(PyObject *) PyWeakref_GetObject(PyObject *ref); PyAPI_FUNC(Py_ssize_t) _PyWeakref_GetWeakrefCount(PyWeakReference *head); PyAPI_FUNC(void) _PyWeakref_ClearRef(PyWeakReference *self); #define PyWeakref_GET_OBJECT(ref) (((PyWeakReference *)(ref))->wr_object)  #ifdef __cplusplus}#endif#endif /* !Py_WEAKREFOBJECT_H */