/*
* 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; // 维护一个类型指针 public:
typedef _Tp element_type; // 构造函数，初始化所维护的指针
explicit auto_ptr(_Tp* __p = ) __STL_NOTHROW : _M_ptr(__p) {} // 拷贝构造函数，转移控制权，将__a维护的指针转交给当前对象来维护；
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 */ // 赋值构造函数，重新设定控制权
auto_ptr& operator=(auto_ptr& __a) __STL_NOTHROW {
if (&__a != this) {
delete _M_ptr; // 解除当前控制权，将所维护的指针所指向的对象析构掉。
_M_ptr = __a.release(); // 重新设定控制权，将__a维护的指针转交给当前对象来维护。
}
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; } // 析构函数，释放所维护指针指向的资源 _Tp& operator*() const __STL_NOTHROW {
return *_M_ptr; // 重载*操作符，返回对象引用
}
_Tp* operator->() const __STL_NOTHROW {
return _M_ptr; // 重载->操作符，返回对象地址
}
_Tp* get() const __STL_NOTHROW {
return _M_ptr; // 获取所维护指针
}
_Tp* release() __STL_NOTHROW {
_Tp* __tmp = _M_ptr;
_M_ptr = ; // 转移控制权，当前对象不再维护任何指针
return __tmp; // 让出控制权
}
// 重新设定控制权，如果以默认值调用，则释放对象，结束控制权
void reset(_Tp* __p = ) __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: