+ struct auto_ptr_ref
+ {
+ _Tp1* _M_ptr;
+
+ explicit
+ auto_ptr_ref(_Tp1* __p): _M_ptr(__p) { }
+ } _GLIBCXX_DEPRECATED;
+
+
+ /**
+ * @brief A simple smart pointer providing strict ownership semantics.
+ *
+ * The Standard says:
+ *
+ * An @c auto_ptr owns the object it holds a pointer to. Copying
+ * an @c auto_ptr copies the pointer and transfers ownership to the
+ * destination. If more than one @c auto_ptr owns the same object
+ * at the same time the behavior of the program is undefined.
+ *
+ * The uses of @c auto_ptr include providing temporary
+ * exception-safety for dynamically allocated memory, passing
+ * ownership of dynamically allocated memory to a function, and
+ * returning dynamically allocated memory from a function. @c
+ * auto_ptr does not meet the CopyConstructible and Assignable
+ * requirements for Standard Library container elements and thus
+ * instantiating a Standard Library container with an @c auto_ptr
+ * results in undefined behavior.
+ *
+ * Quoted from [20.4.5]/3.
+ *
+ * Good examples of what can and cannot be done with auto_ptr can
+ * be found in the libstdc++ testsuite.
+ *
+ * _GLIBCXX_RESOLVE_LIB_DEFECTS
+ * 127. auto_ptr<> conversion issues
+ * These resolutions have all been incorporated.
+ */
+ template
+ class auto_ptr
+ {
+ private:
+ _Tp* _M_ptr;
+
+ public:
+ /// The pointed-to type.
+ typedef _Tp element_type;
+
+ /**
+ * @brief An %auto_ptr is usually constructed from a raw pointer.
+ * @param __p A pointer (defaults to NULL).
+ *
+ * This object now @e owns the object pointed to by @a __p.
+ */
+ explicit
+ auto_ptr(element_type* __p = 0) throw() : _M_ptr(__p) { }
+
+ /**
+ * @brief An %auto_ptr can be constructed from another %auto_ptr.
+ * @param __a Another %auto_ptr of the same type.
+ *
+ * This object now @e owns the object previously owned by @a __a,
+ * which has given up ownership.
+ */
+ auto_ptr(auto_ptr& __a) throw() : _M_ptr(__a.release()) { }
+
+ /**
+ * @brief An %auto_ptr can be constructed from another %auto_ptr.
+ * @param __a Another %auto_ptr of a different but related type.
+ *
+ * A pointer-to-Tp1 must be convertible to a
+ * pointer-to-Tp/element_type.
+ *
+ * This object now @e owns the object previously owned by @a __a,
+ * which has given up ownership.
+ */
+ template
+ auto_ptr(auto_ptr<_Tp1>& __a) throw() : _M_ptr(__a.release()) { }
+
+ /**
+ * @brief %auto_ptr assignment operator.
+ * @param __a Another %auto_ptr of the same type.
+ *
+ * This object now @e owns the object previously owned by @a __a,
+ * which has given up ownership. The object that this one @e
+ * used to own and track has been deleted.
+ */
+ auto_ptr&
+ operator=(auto_ptr& __a) throw()
+ {
+ reset(__a.release());
+ return *this;
+ }
+
+ /**
+ * @brief %auto_ptr assignment operator.
+ * @param __a Another %auto_ptr of a different but related type.
+ *
+ * A pointer-to-Tp1 must be convertible to a pointer-to-Tp/element_type.
+ *
+ * This object now @e owns the object previously owned by @a __a,
+ * which has given up ownership. The object that this one @e
+ * used to own and track has been deleted.
+ */
+ template
+ auto_ptr&
+ operator=(auto_ptr<_Tp1>& __a) throw()
+ {
+ reset(__a.release());
+ return *this;
+ }
+
+ /**
+ * When the %auto_ptr goes out of scope, the object it owns is
+ * deleted. If it no longer owns anything (i.e., @c get() is
+ * @c NULL), then this has no effect.
+ *
+ * The C++ standard says there is supposed to be an empty throw
+ * specification here, but omitting it is standard conforming. Its
+ * presence can be detected only if _Tp::~_Tp() throws, but this is
+ * prohibited. [17.4.3.6]/2
+ */
+ ~auto_ptr() { delete _M_ptr; }
+
+ /**
+ * @brief Smart pointer dereferencing.
+ *
+ * If this %auto_ptr no longer owns anything, then this
+ * operation will crash. (For a smart pointer, no longer owns
+ * anything is the same as being a null pointer, and you know
+ * what happens when you dereference one of those...)
+ */
+ element_type&
+ operator*() const throw()
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0);
+ return *_M_ptr;
+ }
+
+ /**
+ * @brief Smart pointer dereferencing.
+ *
+ * This returns the pointer itself, which the language then will
+ * automatically cause to be dereferenced.
+ */
+ element_type*
+ operator->() const throw()
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0);
+ return _M_ptr;
+ }
+
+ /**
+ * @brief Bypassing the smart pointer.
+ * @return The raw pointer being managed.
+ *
+ * You can get a copy of the pointer that this object owns, for
+ * situations such as passing to a function which only accepts
+ * a raw pointer.
+ *
+ * @note This %auto_ptr still owns the memory.
+ */
+ element_type*
+ get() const throw() { return _M_ptr; }
+
+ /**
+ * @brief Bypassing the smart pointer.
+ * @return The raw pointer being managed.
+ *
+ * You can get a copy of the pointer that this object owns, for
+ * situations such as passing to a function which only accepts
+ * a raw pointer.
+ *
+ * @note This %auto_ptr no longer owns the memory. When this object
+ * goes out of scope, nothing will happen.
+ */
+ element_type*
+ release() throw()
+ {
+ element_type* __tmp = _M_ptr;
+ _M_ptr = 0;
+ return __tmp;
+ }
+
+ /**
+ * @brief Forcibly deletes the managed object.
+ * @param __p A pointer (defaults to NULL).
+ *
+ * This object now @e owns the object pointed to by @a __p. The
+ * previous object has been deleted.
+ */
+ void
+ reset(element_type* __p = 0) throw()
+ {
+ if (__p != _M_ptr)
+ {
+ delete _M_ptr;
+ _M_ptr = __p;
+ }
+ }
+
+ /**
+ * @brief Automatic conversions
+ *
+ * These operations convert an %auto_ptr into and from an auto_ptr_ref
+ * automatically as needed. This allows constructs such as
+ * @code
+ * auto_ptr func_returning_auto_ptr(.....);
+ * ...
+ * auto_ptr ptr = func_returning_auto_ptr(.....);
+ * @endcode
+ */
+ auto_ptr(auto_ptr_ref __ref) throw()
+ : _M_ptr(__ref._M_ptr) { }
+
+ auto_ptr&
+ operator=(auto_ptr_ref __ref) throw()
+ {
+ if (__ref._M_ptr != this->get())
+ {
+ delete _M_ptr;
+ _M_ptr = __ref._M_ptr;
+ }
+ return *this;
+ }
+
+ template
+ operator auto_ptr_ref<_Tp1>() throw()
+ { return auto_ptr_ref<_Tp1>(this->release()); }
+
+ template
+ operator auto_ptr<_Tp1>() throw()
+ { return auto_ptr<_Tp1>(this->release()); }
+ } _GLIBCXX_DEPRECATED;
+
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 541. shared_ptr template assignment and void
+ template<>
+ class auto_ptr
+ {
+ public:
+ typedef void element_type;
+ } _GLIBCXX_DEPRECATED;
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+
+#endif /* _BACKWARD_AUTO_PTR_H */