auto_ptr源码剖析

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/*  * Copyright (c) 1997-1999  * Silicon Graphics Computer Systems, Inc.  *  * Permission to use, copy, modify, distribute and sell this software  * and its documentation for any purpose is hereby granted without fee,  * provided that the above copyright notice appear in all copies and  * that both that copyright notice and this permission notice appear  * in supporting documentation.  Silicon Graphics makes no  * representations about the suitability of this software for any  * purpose.  It is provided "as is" without express or implied warranty.  *  */

#ifndef __SGI_STL_MEMORY #define __SGI_STL_MEMORY

#include <stl_algobase.h> #include <stl_alloc.h> #include <stl_construct.h> #include <stl_tempbuf.h> #include <stl_uninitialized.h> #include <stl_raw_storage_iter.h>

__STL_BEGIN_NAMESPACE

#if defined(__SGI_STL_USE_AUTO_PTR_CONVERSIONS) && \     defined(__STL_MEMBER_TEMPLATES)

template<class _Tp1> struct auto_ptr_ref {   _Tp1* _M_ptr;   auto_ptr_ref(_Tp1* __p) : _M_ptr(__p) {} };

#endif

template <class _Tp> class auto_ptr { private:   _Tp* _M_ptr;

public:   typedef _Tp element_type;

  explicit auto_ptr(_Tp* __p = 0) __STL_NOTHROW : _M_ptr(__p) {}   auto_ptr(auto_ptr& __a) __STL_NOTHROW : _M_ptr(__a.release()) {}

#ifdef __STL_MEMBER_TEMPLATES   template <class _Tp1> auto_ptr(auto_ptr<_Tp1>& __a) __STL_NOTHROW     : _M_ptr(__a.release()) {} #endif /* __STL_MEMBER_TEMPLATES */

  auto_ptr& operator=(auto_ptr& __a) __STL_NOTHROW {     if (&__a != this) {       delete _M_ptr;       _M_ptr = __a.release();     }     return *this;   }

#ifdef __STL_MEMBER_TEMPLATES   template <class _Tp1>   auto_ptr& operator=(auto_ptr<_Tp1>& __a) __STL_NOTHROW {     if (__a.get() != this->get()) {       delete _M_ptr;       _M_ptr = __a.release();     }     return *this;   } #endif /* __STL_MEMBER_TEMPLATES */

  // Note: 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 (17.4.3.6/2)   // this is prohibited.   ~auto_ptr() { delete _M_ptr; }

  _Tp& operator*() const __STL_NOTHROW {     return *_M_ptr;   }   _Tp* operator->() const __STL_NOTHROW {     return _M_ptr;   }   _Tp* get() const __STL_NOTHROW {     return _M_ptr;   }   _Tp* release() __STL_NOTHROW {     _Tp* __tmp = _M_ptr;     _M_ptr = 0;     return __tmp;   }   void reset(_Tp* __p = 0) __STL_NOTHROW {     if (__p != _M_ptr) {       delete _M_ptr;       _M_ptr = __p;     }   }

  // According to the C++ standard, these conversions are required.  Most   // present-day compilers, however, do not enforce that requirement---and,   // in fact, most present-day compilers do not support the language   // features that these conversions rely on.   #if defined(__SGI_STL_USE_AUTO_PTR_CONVERSIONS) && \     defined(__STL_MEMBER_TEMPLATES)

public:   auto_ptr(auto_ptr_ref<_Tp> __ref) __STL_NOTHROW     : _M_ptr(__ref._M_ptr) {}

  auto_ptr& operator=(auto_ptr_ref<_Tp> __ref) __STL_NOTHROW {     if (__ref._M_ptr != this->get()) {       delete _M_ptr;       _M_ptr = __ref._M_ptr;     }     return *this;   }

  template <class _Tp1> operator auto_ptr_ref<_Tp1>() __STL_NOTHROW     { return auto_ptr_ref<_Tp1>(this->release()); }   template <class _Tp1> operator auto_ptr<_Tp1>() __STL_NOTHROW     { return auto_ptr<_Tp1>(this->release()); }

#endif /* auto ptr conversions && member templates */ };

__STL_END_NAMESPACE

#endif /* __SGI_STL_MEMORY */

// Local Variables: // mode:C++ // End:

auto_ptr源码剖析

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原文地址：http://www.cnblogs.com/pbendan/p/4625929.html