_auto_ptr.h

MONA是为数不多的C++语言编写的一个很小的操作系统

/*
 * Copyright (c) 1997-1999
 * Silicon Graphics Computer Systems, Inc.
 *
 * Copyright (c) 1999 
 * Boris Fomitchev
 *
 * This material is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * Permission to use or copy this software for any purpose is hereby granted 
 * without fee, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */

#ifndef _STLP_AUTO_PTR_H
# define _STLP_AUTO_PTR_H

_STLP_BEGIN_NAMESPACE
// implementation primitive
class __ptr_base {
public:
  void* _M_p;
  void  __set(const void* p) { _M_p = __CONST_CAST(void*,p); }
  void  __set(void* p) { _M_p = p; }
};

template <class _Tp> class auto_ptr_ref {
public:
  __ptr_base& _M_r;
  _Tp* const _M_p;

  auto_ptr_ref(__ptr_base& __r, _Tp* __p) : _M_r(__r), _M_p(__p) {  }

  _Tp* release() const { _M_r.__set((void*)0); return _M_p; }

};

template<class _Tp> class auto_ptr :  public __ptr_base {
public:	
  typedef _Tp element_type;
  typedef auto_ptr<_Tp>           _Self;
  
  _Tp* release() {  
    _Tp* __px = this->get(); 
    this->_M_p = 0; 
    return __px; 
  }
  
  void reset(_Tp* __px=0) {
    _Tp* __pt = this->get();
    if (__px != __pt) 
      delete __pt; 
    this->__set(__px); 
  }

  _Tp* get() const { return __REINTERPRET_CAST(_Tp*,__CONST_CAST(void*,_M_p)); } 

# if !defined (_STLP_NO_ARROW_OPERATOR)
  _Tp* operator->() const { 
    _STLP_VERBOSE_ASSERT(get()!=0, _StlMsg_AUTO_PTR_NULL)
    return get(); 
  }
# endif
  _Tp& operator*() const  { 
    _STLP_VERBOSE_ASSERT(get()!=0, _StlMsg_AUTO_PTR_NULL)
    return *get(); 
  }
  
  auto_ptr() { this->_M_p = 0; }
  
  explicit auto_ptr(_Tp* __px) { this->__set(__px); }
  
#if defined (_STLP_MEMBER_TEMPLATES)
# if !defined (_STLP_NO_TEMPLATE_CONVERSIONS)
  template<class _Tp1> auto_ptr(auto_ptr<_Tp1>& __r) {
    _Tp* __conversionCheck = __r.release();
    this->__set(__conversionCheck);
  }
# endif	
  template<class _Tp1> auto_ptr<_Tp>& operator=(auto_ptr<_Tp1>& __r) {
    _Tp* __conversionCheck = __r.release();
    reset(__conversionCheck);
    return *this;
  }
#endif /* _STLP_MEMBER_TEMPLATES */
  
  auto_ptr(_Self& __r) { this->__set(__r.release()); }

  _Self& operator=(_Self& __r)  {
    reset(__r.release());
    return *this;
  }

  ~auto_ptr() { /* boris : reset(0) might be better */ delete this->get(); }
	
  auto_ptr(auto_ptr_ref<_Tp> __r) {
    this->__set(__r.release());
  }
	
  _Self& operator=(auto_ptr_ref<_Tp> __r) {
    reset(__r.release());
    return *this;
  }
  
# if defined(_STLP_MEMBER_TEMPLATES) && !defined(_STLP_NO_TEMPLATE_CONVERSIONS)
  template<class _Tp1> operator auto_ptr_ref<_Tp1>() {
    return auto_ptr_ref<_Tp1>(*this, this->get());
  }
  template<class _Tp1> operator auto_ptr<_Tp1>() {
    return auto_ptr<_Tp1>(release());
  }
# else
  operator auto_ptr_ref<_Tp>()
  { return auto_ptr_ref<_Tp>(*this, this->get()); }
# endif
	
};
_STLP_END_NAMESPACE

#endif /* _STLP_AUTO_PTR_H */

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