std::auto_ptr

std::auto_ptr< _Tp > Class Template Reference

A simple smart pointer providing strict ownership semantics. More...

List of all members.

Public Types

typedef _Tp element_type
 The pointed-to type.

Public Member Functions

 auto_ptr (element_type *__p=0) throw ()
 An auto_ptr is usually constructed from a raw pointer.
 auto_ptr (auto_ptr &__a) throw ()
 An auto_ptr can be constructed from another auto_ptr.
template<typename _Tp1>
 auto_ptr (auto_ptr< _Tp1 > &__a) throw ()
 An auto_ptr can be constructed from another auto_ptr.
auto_ptr & operator= (auto_ptr &__a) throw ()
 auto_ptr assignment operator.
template<typename _Tp1>
auto_ptr & operator= (auto_ptr< _Tp1 > &__a) throw ()
 auto_ptr assignment operator.
 ~auto_ptr ()
element_type & operator * () const throw ()
 Smart pointer dereferencing.
element_type * operator-> () const throw ()
 Smart pointer dereferencing.
element_type * get () const throw ()
 Bypassing the smart pointer.
element_type * release () throw ()
 Bypassing the smart pointer.
void reset (element_type *__p=0) throw ()
 Forcibly deletes the managed object.
 auto_ptr (auto_ptr_ref< element_type > __ref) throw ()
 Automatic conversions.
auto_ptr & operator= (auto_ptr_ref< element_type > __ref) throw ()
template<typename _Tp1>
 operator auto_ptr_ref () throw ()
template<typename _Tp1>
 operator auto_ptr () throw ()

Private Attributes

_Tp * _M_ptr

Detailed Description

template<typename _Tp>
class std::auto_ptr< _Tp >

A simple smart pointer providing strict ownership semantics.

The Standard says: 

  An auto_ptr owns the object it holds a pointer to.  Copying
  an auto_ptr copies the pointer and transfers ownership to the
  destination.  If more than one auto_ptr owns the same object
  at the same time the behavior of the program is undefined.

  The uses of 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.  auto_ptr does not meet the CopyConstructible and Assignable
  requirements for Standard Library container elements and thus
  instantiating a Standard Library container with an 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.

Definition at line 174 of file memory.

Member Typedef Documentation

template<typename _Tp>
typedef _Tp std::auto_ptr< _Tp >::element_type

The pointed-to type.

Definition at line 181 of file memory.

Constructor & Destructor Documentation

template<typename _Tp>
std::auto_ptr< _Tp >::auto_ptr ( element_type *  __p = 0  )  throw () [inline, explicit]

An auto_ptr is usually constructed from a raw pointer.

Parameters:
p A pointer (defaults to NULL).
This object now owns the object pointed to by p.

Definition at line 190 of file memory.

template<typename _Tp>
std::auto_ptr< _Tp >::auto_ptr ( auto_ptr< _Tp > &  __a  )  throw () [inline]

An auto_ptr can be constructed from another auto_ptr.

Parameters:
a Another auto_ptr of the same type.
This object now owns the object previously owned by a, which has given up ownsership.

Definition at line 199 of file memory.

template<typename _Tp>
template<typename _Tp1>
std::auto_ptr< _Tp >::auto_ptr ( auto_ptr< _Tp1 > &  __a  )  throw () [inline]

An auto_ptr can be constructed from another auto_ptr.

Parameters:
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 owns the object previously owned by a, which has given up ownsership.

Definition at line 212 of file memory.

template<typename _Tp>
std::auto_ptr< _Tp >::~auto_ptr (  )  [inline]

When the auto_ptr goes out of scope, the object it owns is deleted. If it no longer owns anything (i.e., get() is NULL), then this has no effect.

Definition at line 259 of file memory.

References std::auto_ptr< _Tp >::_M_ptr.

template<typename _Tp>
std::auto_ptr< _Tp >::auto_ptr ( auto_ptr_ref< element_type >  __ref  )  throw () [inline]

Automatic conversions.

These operations convert an auto_ptr into and from an auto_ptr_ref automatically as needed. This allows constructs such as 

    auto_ptr<Derived>  func_returning_auto_ptr(.....);
    ...
    auto_ptr<Base> ptr = func_returning_auto_ptr(.....);

Definition at line 349 of file memory.

Member Function Documentation

template<typename _Tp>
element_type* std::auto_ptr< _Tp >::get ( void   )  const throw () [inline]

Bypassing the smart pointer.

Returns:
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.

Definition at line 300 of file memory.

References std::auto_ptr< _Tp >::_M_ptr.

Referenced by std::tr1::shared_ptr< _Tp >::shared_ptr().

template<typename _Tp>
element_type& std::auto_ptr< _Tp >::operator * (  )  const throw () [inline]

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...)

Definition at line 270 of file memory.

References _GLIBCXX_DEBUG_ASSERT, and std::auto_ptr< _Tp >::_M_ptr.

template<typename _Tp>
template<typename _Tp1>
std::auto_ptr< _Tp >::operator auto_ptr (  )  throw () [inline]

Definition at line 368 of file memory.

References std::auto_ptr< _Tp >::release().

template<typename _Tp>
template<typename _Tp1>
std::auto_ptr< _Tp >::operator auto_ptr_ref (  )  throw () [inline]

Definition at line 364 of file memory.

References std::auto_ptr< _Tp >::release().

template<typename _Tp>
element_type* std::auto_ptr< _Tp >::operator-> (  )  const throw () [inline]

Smart pointer dereferencing.

This returns the pointer itself, which the language then will automatically cause to be dereferenced.

Definition at line 283 of file memory.

References _GLIBCXX_DEBUG_ASSERT, and std::auto_ptr< _Tp >::_M_ptr.

template<typename _Tp>
auto_ptr& std::auto_ptr< _Tp >::operator= ( auto_ptr_ref< element_type >  __ref  )  throw () [inline]

Definition at line 353 of file memory.

References std::auto_ptr< _Tp >::_M_ptr.

template<typename _Tp>
template<typename _Tp1>
auto_ptr& std::auto_ptr< _Tp >::operator= ( auto_ptr< _Tp1 > &  __a  )  throw () [inline]

auto_ptr assignment operator.

Parameters:
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 owns the object previously owned by a, which has given up ownsership. The object that this one used to own and track has been deleted.

Definition at line 241 of file memory.

References std::auto_ptr< _Tp >::release(), and std::auto_ptr< _Tp >::reset().

template<typename _Tp>
auto_ptr& std::auto_ptr< _Tp >::operator= ( auto_ptr< _Tp > &  __a  )  throw () [inline]

auto_ptr assignment operator.

Parameters:
a Another auto_ptr of the same type.
This object now owns the object previously owned by a, which has given up ownsership. The object that this one used to own and track has been deleted.

Definition at line 223 of file memory.

References std::auto_ptr< _Tp >::release(), and std::auto_ptr< _Tp >::reset().

template<typename _Tp>
element_type* std::auto_ptr< _Tp >::release (  )  throw () [inline]

Bypassing the smart pointer.

Returns:
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.

Definition at line 314 of file memory.

References std::auto_ptr< _Tp >::_M_ptr.

Referenced by std::auto_ptr< _Tp >::operator auto_ptr(), std::auto_ptr< _Tp >::operator auto_ptr_ref(), std::auto_ptr< _Tp >::operator=(), and std::tr1::shared_count::shared_count().

template<typename _Tp>
void std::auto_ptr< _Tp >::reset ( element_type *  __p = 0  )  throw () [inline]

Forcibly deletes the managed object.

Parameters:
p A pointer (defaults to NULL).
This object now owns the object pointed to by p. The previous object has been deleted.

Definition at line 329 of file memory.

References std::auto_ptr< _Tp >::_M_ptr.

Referenced by std::auto_ptr< _Tp >::operator=().

Member Data Documentation

template<typename _Tp>
_Tp* std::auto_ptr< _Tp >::_M_ptr [private]

Definition at line 177 of file memory.

Referenced by std::auto_ptr< _Tp >::get(), std::auto_ptr< _Tp >::operator *(), std::auto_ptr< _Tp >::operator->(), std::auto_ptr< _Tp >::operator=(), std::auto_ptr< _Tp >::release(), std::auto_ptr< _Tp >::reset(), and std::auto_ptr< _Tp >::~auto_ptr().

The documentation for this class was generated from the following file:
Generated on Tue Feb 2 16:59:30 2010 for GNU C++ STL by  doxygen 1.4.7