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30 
31 // Author: tibell@google.com (Johan Tibell)
32 
33 #ifndef GOOGLE_PROTOBUF_PYTHON_CPP_SCOPED_PYOBJECT_PTR_H__
34 #define GOOGLE_PROTOBUF_PYTHON_CPP_SCOPED_PYOBJECT_PTR_H__
35 
36 #include <Python.h>
37 
38 namespace google {
39 class ScopedPyObjectPtr {
40  public:
41   // Constructor.  Defaults to intializing with NULL.
42   // There is no way to create an uninitialized ScopedPyObjectPtr.
ptr_(p)43   explicit ScopedPyObjectPtr(PyObject* p = NULL) : ptr_(p) { }
44 
45   // Destructor.  If there is a PyObject object, delete it.
~ScopedPyObjectPtr()46   ~ScopedPyObjectPtr() {
47     Py_XDECREF(ptr_);
48   }
49 
50   // Reset.  Deletes the current owned object, if any.
51   // Then takes ownership of a new object, if given.
52   // this->reset(this->get()) works.
53   PyObject* reset(PyObject* p = NULL) {
54     if (p != ptr_) {
55       Py_XDECREF(ptr_);
56       ptr_ = p;
57     }
58     return ptr_;
59   }
60 
61   // Releases ownership of the object.
release()62   PyObject* release() {
63     PyObject* p = ptr_;
64     ptr_ = NULL;
65     return p;
66   }
67 
68   operator PyObject*() { return ptr_; }
69 
70   PyObject* operator->() const  {
71     assert(ptr_ != NULL);
72     return ptr_;
73   }
74 
get()75   PyObject* get() const { return ptr_; }
76 
refcnt()77   Py_ssize_t refcnt() const { return Py_REFCNT(ptr_); }
78 
inc()79   void inc() const { Py_INCREF(ptr_); }
80 
81   // Comparison operators.
82   // These return whether a ScopedPyObjectPtr and a raw pointer
83   // refer to the same object, not just to two different but equal
84   // objects.
85   bool operator==(const PyObject* p) const { return ptr_ == p; }
86   bool operator!=(const PyObject* p) const { return ptr_ != p; }
87 
88  private:
89   PyObject* ptr_;
90 
91   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ScopedPyObjectPtr);
92 };
93 
94 }  // namespace google
95 #endif  // GOOGLE_PROTOBUF_PYTHON_CPP_SCOPED_PYOBJECT_PTR_H__
96