《STL源码剖析》--<stl_construct.h>

// Filename:    stl_construct.h// Comment By:  凝霜// E-mail:      [e-mail]// Blog:        http://blog.csdn.net/mdl13412/* * * Copyright (c) 1994 * Hewlett-Packard Company * * 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.  Hewlett-Packard Company makes no * representations about the suitability of this software for any * purpose.  It is provided "as is" without express or implied warranty. * * * Copyright (c) 1996,1997 * 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. *//* NOTE: This is an internal header file, included by other STL headers. *   You should not attempt to use it directly. */#ifndef __SGI_STL_INTERNAL_CONSTRUCT_H#define __SGI_STL_INTERNAL_CONSTRUCT_H#include <new.h>        // 需要placement new的原型__STL_BEGIN_NAMESPACE// 调用成员的析构函数, 需要类型具有non-trivial destructortemplate <class T>inline void destroy(T* pointer){    pointer->~T();}// 使用placement new在已经分配的内存上构造对象// 如果你不熟悉placement new, 请参考// http://msdn.microsoft.com/en-us/library/kewsb8ba.aspx// http://blogs.msdn.com/b/jaredpar/archive///        2007/10/16/c-new-operator-and-placement-new.aspxtemplate <class T1, class T2>inline void construct(T1* p, const T2& value){  new (p) T1(value);}// 析构一组对象, 用于具有non-trivial destructortemplate <class ForwardIterator>inline void__destroy_aux(ForwardIterator first, ForwardIterator last, __false_type){  for ( ; first < last; ++first)    destroy(&*first);}// 如果没有类型non-trivial destructor, 则使用此函数template <class ForwardIterator>inline void __destroy_aux(ForwardIterator, ForwardIterator, __true_type) {}// 使用traits技术, 判断类型是否就有non-trivial destructor, 然后调用不同的函数template <class ForwardIterator, class T>inline void __destroy(ForwardIterator first, ForwardIterator last, T*){  typedef typename __type_traits<T>::has_trivial_destructor trivial_destructor;  __destroy_aux(first, last, trivial_destructor());}////////////////////////////////////////////////////////////////////////////////// 用于销毁一组对象//////////////////////////////////////////////////////////////////////////////////                                                char *特化版本//                                               ---------- destroy不进行析构//                                               |// destroy(first, last) -------------------------- 特化//                                   |           |//                                   |  泛化     ----------- destroy不进行析构//                                   |           wchar_t *特化版本//                                   ↓//                调用 __destroy(first, last, value_type(first));//                根据是否具有trivial destructor进行函数转发//                                   |//                                   |---------------- has trivial destructor?//                                   |//               -------------------------------------------//        No     |                                         | Yes//               |                                         |//               ↓                                         ↓// __destroy_aux(..., __true_type)           __destroy_aux(..., __false_type)// 不进需要行析构操作                          for ( ; first < last; ++first)//                                              destroy(&*first);////////////////////////////////////////////////////////////////////////////////template <class ForwardIterator>inline void destroy(ForwardIterator first, ForwardIterator last){  __destroy(first, last, value_type(first));}// 特化版本inline void destroy(char*, char*) {}inline void destroy(wchar_t*, wchar_t*) {}__STL_END_NAMESPACE#endif /* __SGI_STL_INTERNAL_CONSTRUCT_H */// Local Variables:// mode:C++// End: