STL源码剖析——vector

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// Filename:    stl_vector.h// Comment By:  凝霜// E-mail:      mdl2009@vip.qq.com// 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 * 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_VECTOR_H#define __SGI_STL_INTERNAL_VECTOR_H__STL_BEGIN_NAMESPACE#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)#pragma set woff 1174#endif//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// 默认allocator为alloc, 其具体使用版本请参照<stl_alloc.h>template <class T, class Alloc = alloc>class vector{public:  // 标记为'STL标准强制要求'的typedefs用于提供iterator_traits<I>支持  typedef T value_type;                         // STL标准强制要求  typedef value_type* pointer;                  // STL标准强制要求  typedef const value_type* const_pointer;  // 由于vector的特性, 一般我们实作的时候都分配给其连续的内存空间,  // 所以其迭代器只需要定义成原生指针即可满足需要  typedef value_type* iterator;                 // STL标准强制要求  typedef const value_type* const_iterator;  typedef value_type& reference;                // STL标准强制要求  typedef const value_type& const_reference;  typedef size_t size_type;  typedef ptrdiff_t difference_type;            // STL标准强制要求#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION  typedef reverse_iterator<const_iterator> const_reverse_iterator;  typedef reverse_iterator<iterator> reverse_iterator;#else /* __STL_CLASS_PARTIAL_SPECIALIZATION */  typedef reverse_iterator<const_iterator, value_type, const_reference,                           difference_type>  const_reverse_iterator;  typedef reverse_iterator<iterator, value_type, reference, difference_type>          reverse_iterator;#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */protected:  // 这个提供STL标准的allocator接口  typedef simple_alloc<value_type, Alloc> data_allocator;  iterator start;               // 内存空间起始点  iterator finish;              // 当前使用的内存空间结束点  iterator end_of_storage;      // 实际分配内存空间的结束点  void insert_aux(iterator position, const T& x);  // 释放分配的内存空间  void deallocate()  {    // 由于使用的是data_allocator进行内存空间的分配,    // 所以需要同样嗲用data_allocator::deallocate()进行释放    // 如果直接释放, 对于data_allocator内部使用内存池的版本    // 就会发生错误    if (start) data_allocator::deallocate(start, end_of_storage - start);  }  void fill_initialize(size_type n, const T& value)  {    start = allocate_and_fill(n, value);    finish = start + n;                         // 设置当前使用内存空间的结束点    // 构造阶段, 此实作不多分配内存,    // 所以要设置内存空间结束点和, 已经使用的内存空间结束点相同    end_of_storage = finish;  }public:  // 获取几种迭代器  iterator begin() { return start; }  const_iterator begin() const { return start; }  iterator end() { return finish; }  const_iterator end() const { return finish; }  reverse_iterator rbegin() { return reverse_iterator(end()); }  const_reverse_iterator rbegin() const {    return const_reverse_iterator(end());  }  reverse_iterator rend() { return reverse_iterator(begin()); }  const_reverse_iterator rend() const {    return const_reverse_iterator(begin());  }  // 返回当前对象个数  size_type size() const { return size_type(end() - begin()); }  size_type max_size() const { return size_type(-1) / sizeof(T); }  // 返回重新分配内存前最多能存储的对象个数  size_type capacity() const { return size_type(end_of_storage - begin()); }  bool empty() const { return begin() == end(); }  reference operator[](size_type n) { return *(begin() + n); }  const_reference operator[](size_type n) const { return *(begin() + n); }  // 本实作中默认构造出的vector不分配内存空间  vector() : start(0), finish(0), end_of_storage(0) {}////////////////////////////////////////////////////////////////////////////////// 本实作中给定个数和对象, 则只分配所需内存, 不会多分配//////////////////////////////////////////////////////////////////////////////////                    vector(size_type n, const T& value)//                                   ↓//                         fill_initialize(n, value)//                                   ↓//                        allocate_and_fill(n, value)//                                   ↓//          data_allocator::allocate(n)          <stl_alloc.h>//          uninitialized_fill_n(result, n, x)  <stl_uninitialized.h>////////////////////////////////////////////////////////////////////////////////  vector(size_type n, const T& value) { fill_initialize(n, value); }  vector(int n, const T& value) { fill_initialize(n, value); }  vector(long n, const T& value) { fill_initialize(n, value); }  // 需要对象提供默认构造函数  explicit vector(size_type n) { fill_initialize(n, T()); }////////////////////////////////////////////////////////////////////////////////// 复制构造, 同样不会多分配内存//////////////////////////////////////////////////////////////////////////////////                     vector(const vector<T, Alloc>& x)//                                   ↓//         allocate_and_copy(x.end() - x.begin(), x.begin(), x.end());//                                   ↓//        data_allocator::allocate(n)              <stl_alloc.h>//        uninitialized_copy(first, last, result); <stl_uninitialized.h>////////////////////////////////////////////////////////////////////////////////  vector(const vector<T, Alloc>& x)  {    start = allocate_and_copy(x.end() - x.begin(), x.begin(), x.end());    finish = start + (x.end() - x.begin());    end_of_storage = finish;  }// 复制指定区间的元素, 同样不多分配内存#ifdef __STL_MEMBER_TEMPLATES////////////////////////////////////////////////////////////////////////////////// 复制一个区间进行构造, 可能会导致多分配内存//////////////////////////////////////////////////////////////////////////////////               vector(InputIterator first, InputIterator last)//                                   ↓//            range_initialize(first, last, iterator_category(first));//                                   ↓//                     for ( ; first != last; ++first)//                         push_back(*first);//            由于使用push_back()操作, 可能导致多次重复分配内存,个人感觉应该先//            data_allocator::allocate((last - first) * sizeof(T));//            然后uninitialized_copy(first, last, result);//            这样不会多分配内存, 也不会导致多次重新分配内存问题////////////////////////////////////////////////////////////////////////////////  template <class InputIterator>  vector(InputIterator first, InputIterator last) :    start(0), finish(0), end_of_storage(0)  {    range_initialize(first, last, iterator_category(first));  }#else /* __STL_MEMBER_TEMPLATES */////////////////////////////////////////////////////////////////////////////////// 复制一个区间进行构造, 可能会导致多分配内存//////////////////////////////////////////////////////////////////////////////////              vector(const_iterator first, const_iterator last)//                                   ↓//                        distance(first, last, n);//                                   ↓//                      allocate_and_copy(n, first, last);//                                   ↓//       data_allocator::allocate(n)               <stl_alloc.h>//       uninitialized_copy(first, last, result);  <stl_uninitialized.h>////////////////////////////////////////////////////////////////////////////////  vector(const_iterator first, const_iterator last) {    size_type n = 0;    distance(first, last, n);    start = allocate_and_copy(n, first, last);    finish = start + n;    end_of_storage = finish;  }#endif /* __STL_MEMBER_TEMPLATES */  ~vector()  {    // 析构对象    destroy(start, finish);    // 释放内存    deallocate();  }  vector<T, Alloc>& operator=(const vector<T, Alloc>& x);////////////////////////////////////////////////////////////////////////////////// 预留一定空间, 如果n < capacity(), 并不会减少空间//////////////////////////////////////////////////////////////////////////////////                          reserve(size_type n)//                                   ↓//                   allocate_and_copy(n, start, finish)//                   destroy(start, finish);               <stl_construct.h>//                   deallocate();////////////////////////////////////////////////////////////////////////////////  void reserve(size_type n)  {    if (capacity() < n) {      const size_type old_size = size();      iterator tmp = allocate_and_copy(n, start, finish);      destroy(start, finish);      deallocate();      start = tmp;      finish = tmp + old_size;      end_of_storage = start + n;    }  }  // 提供访问函数  reference front() { return *begin(); }  const_reference front() const { return *begin(); }  reference back() { return *(end() - 1); }  const_reference back() const { return *(end() - 1); }////////////////////////////////////////////////////////////////////////////////// 向容器尾追加一个元素, 可能导致内存重新分配//////////////////////////////////////////////////////////////////////////////////                          push_back(const T& x)//                                   |//                                   |---------------- 容量已满?//                                   |//               ----------------------------//           No  |                          |  Yes//               |                          |//               ↓                          ↓//      construct(finish, x);       insert_aux(end(), x);//      ++finish;                           |//                                          |------ 内存不足, 重新分配//                                          |       大小为原来的2倍//      new_finish = data_allocator::allocate(len);       <stl_alloc.h>//      uninitialized_copy(start, position, new_start);   <stl_uninitialized.h>//      construct(new_finish, x);                         <stl_construct.h>//      ++new_finish;//      uninitialized_copy(position, finish, new_finish); <stl_uninitialized.h>////////////////////////////////////////////////////////////////////////////////  void push_back(const T& x)  {    // 内存满足条件则直接追加元素, 否则需要重新分配内存空间    if (finish != end_of_storage) {      construct(finish, x);      ++finish;    }    else      insert_aux(end(), x);  }  // 交换两个vector, 实际上是交换内部的状态指针  void swap(vector<T, Alloc>& x)  {    __STD::swap(start, x.start);    __STD::swap(finish, x.finish);    __STD::swap(end_of_storage, x.end_of_storage);  }////////////////////////////////////////////////////////////////////////////////// 在指定位置插入元素//////////////////////////////////////////////////////////////////////////////////                   insert(iterator position, const T& x)//                                   |//                                   |------------ 容量是否足够 && 是否是end()?//                                   |//               -------------------------------------------//            No |                                         | Yes//               |                                         |//               ↓                                         ↓//    insert_aux(position, x);                  construct(finish, x);//               |                              ++finish;//               |-------- 容量是否够用?//               |//        --------------------------------------------------//    Yes |                                                | No//        |                                                |//        ↓                                                |// construct(finish, *(finish - 1));                       |// ++finish;                                               |// T x_copy = x;                                           |// copy_backward(position, finish - 2, finish - 1);        |// *position = x_copy;                                     |//                                                         ↓// data_allocator::allocate(len);                       <stl_alloc.h>// uninitialized_copy(start, position, new_start);      <stl_uninitialized.h>// construct(new_finish, x);                            <stl_construct.h>// ++new_finish;// uninitialized_copy(position, finish, new_finish);    <stl_uninitialized.h>// destroy(begin(), end());                             <stl_construct.h>// deallocate();////////////////////////////////////////////////////////////////////////////////  iterator insert(iterator position, const T& x)  {    size_type n = position - begin();    if (finish != end_of_storage && position == end()) {      construct(finish, x);      ++finish;    }    else      insert_aux(position, x);    return begin() + n;  }  iterator insert(iterator position) { return insert(position, T()); }#ifdef __STL_MEMBER_TEMPLATES////////////////////////////////////////////////////////////////////////////////// 在指定位置插入一个区间//////////////////////////////////////////////////////////////////////////////////     insert(iterator position, InputIterator first, InputIterator last)//                                   ↓//       range_insert(position, first, last, iterator_category(first));//                                   ↓//                      for ( ; first != last; ++first) {//                              pos = insert(pos, *first);//                               ++pos;//                      }////////////////////////////////////////////////////////////////////////////////  template <class InputIterator>  void insert(iterator position, InputIterator first, InputIterator last)  {    range_insert(position, first, last, iterator_category(first));  }#else /* __STL_MEMBER_TEMPLATES */  void insert(iterator position,              const_iterator first, const_iterator last);#endif /* __STL_MEMBER_TEMPLATES */  void insert (iterator pos, size_type n, const T& x);  void insert (iterator pos, int n, const T& x)  {    insert(pos, (size_type) n, x);  }  void insert (iterator pos, long n, const T& x)  {    insert(pos, (size_type) n, x);  }  void pop_back()  {    --finish;    destroy(finish);  }  iterator erase(iterator position)  {    if (position + 1 != end())      copy(position + 1, finish, position);    --finish;    destroy(finish);    return position;  }////////////////////////////////////////////////////////////////////////////////// 擦除指定区间的元素//////////////////////////////////////////////////////////////////////////////////                 erase(iterator first, iterator last)//                                   ↓//           ---------- copy(last, finish, first);      <stl_algobase.h>//           |          destroy(i, finish);             <stl_construct.h>//           |//           |                                  -------------- copy(...)//           |          特化                    |  char *特化   memmove()//      ---------------------------------------|//      |  泛化                                 |  wchar_t特化  copy(...)//      |                                       -------------- memmove()//      |// 调用__copy_dispatch<InputIterator,OutputIterator>()(first, last, result);// 进行__copy(first, last, result, iterator_category(first));派发//      |//      |//      |                       random_access_iterator_tag// --------------------------------------------------------------// |  input_iterator_tag                                        |// |                                                            |// ↓                                                            |// __copy(..., input_iterator_tag)                              |// for ( ; first != last; ++result, ++first)                    |//    *result = *first;                                         ↓//                         __copy(..., random_access_iterator_tag)//                         __copy_d(first, last, result, distance_type(first));//                                              |//                                              |//                                              ↓//              for (Distance n = last - first; n > 0; --n, ++result, ++first)//                      *result = *first;////////////////////////////////////////////////////////////////////////////////  iterator erase(iterator first, iterator last)  {    iterator i = copy(last, finish, first);    // 析构掉需要析构的元素    destroy(i, finish);    finish = finish - (last - first);    return first;  }  // 调整size, 但是并不会重新分配内存空间  void resize(size_type new_size, const T& x)  {    if (new_size < size())      erase(begin() + new_size, end());    else      insert(end(), new_size - size(), x);  }  void resize(size_type new_size) { resize(new_size, T()); }  void clear() { erase(begin(), end()); }protected:  // 分配空间, 并且复制对象到分配的空间处  iterator allocate_and_fill(size_type n, const T& x)  {    iterator result = data_allocator::allocate(n);    __STL_TRY {      uninitialized_fill_n(result, n, x);      return result;    }    __STL_UNWIND(data_allocator::deallocate(result, n));  }// 分配空间并且拷贝一个区间的元素到新分配空间处#ifdef __STL_MEMBER_TEMPLATES  template <class ForwardIterator>  iterator allocate_and_copy(size_type n,                             ForwardIterator first, ForwardIterator last)  {    iterator result = data_allocator::allocate(n);    __STL_TRY {      uninitialized_copy(first, last, result);      return result;    }    __STL_UNWIND(data_allocator::deallocate(result, n));  }#else /* __STL_MEMBER_TEMPLATES */  iterator allocate_and_copy(size_type n,                             const_iterator first, const_iterator last)  {    iterator result = data_allocator::allocate(n);    __STL_TRY {      uninitialized_copy(first, last, result);      return result;    }    __STL_UNWIND(data_allocator::deallocate(result, n));  }#endif /* __STL_MEMBER_TEMPLATES */#ifdef __STL_MEMBER_TEMPLATES  // 初始化一个区间, 使用push_back()操作, 可能引发内存多次重新分配  // 解决方案见  // template <class InputIterator>  // vector(InputIterator first, InputIterator last)  // 我评注部分  template <class InputIterator>  void range_initialize(InputIterator first, InputIterator last,                        input_iterator_tag)  {    for ( ; first != last; ++first)      push_back(*first);  }  // This function is only called by the constructor.  We have to worry  //  about resource leaks, but not about maintaining invariants.  template <class ForwardIterator>  void range_initialize(ForwardIterator first, ForwardIterator last,                        forward_iterator_tag)  {    size_type n = 0;    distance(first, last, n);    start = allocate_and_copy(n, first, last);    finish = start + n;    end_of_storage = finish;  }  template <class InputIterator>  void range_insert(iterator pos,                    InputIterator first, InputIterator last,                    input_iterator_tag);  template <class ForwardIterator>  void range_insert(iterator pos,                    ForwardIterator first, ForwardIterator last,                    forward_iterator_tag);#endif /* __STL_MEMBER_TEMPLATES */};////////////////////////////////////////////////////////////////////////////////// vector实现部分////////////////////////////////////////////////////////////////////////////////template <class T, class Alloc>inline bool operator==(const vector<T, Alloc>& x, const vector<T, Alloc>& y){  return x.size() == y.size() && equal(x.begin(), x.end(), y.begin());}// 字典序比较template <class T, class Alloc>inline bool operator<(const vector<T, Alloc>& x, const vector<T, Alloc>& y){  return lexicographical_compare(x.begin(), x.end(), y.begin(), y.end());}#ifdef __STL_FUNCTION_TMPL_PARTIAL_ORDERtemplate <class T, class Alloc>inline void swap(vector<T, Alloc>& x, vector<T, Alloc>& y){  x.swap(y);}#endif /* __STL_FUNCTION_TMPL_PARTIAL_ORDER */////////////////////////////////////////////////////////////////////////////////// 重载赋值运算符//////////////////////////////////////////////////////////////////////////////////                  operator=(const vector<T, Alloc>& x)//                                   |//                                   |---------------- 是否是自赋值?//                                   ↓//              -----------------------------------------//        No    |                                       | Yes//              |                                       |//              ↓                                       |------- 容量判断//        return *this;                                 |//                                                      ↓//      -----------------------------------------------------------------//      |x.size() > capacity()          | size() >= x.size()            | other//      |                               |                               |//      ↓                               ↓                               |//  容量不足, 需要重新分配        容量足够, 只需要析构掉多余的对象             |//  allocate_and_copy(         copy(x.begin(), x.end(), begin());       |//      x.end() - x.begin(),   destroy(i, finish);                      |//      x.begin(), x.end());                                            |//  destroy(start, finish);                                             |//  deallocate();                                                       ↓//                     copy(x.begin(), x.begin() + size(), start);//                     uninitialized_copy(x.begin() + size(), x.end(), finish);////////////////////////////////////////////////////////////////////////////////template <class T, class Alloc>vector<T, Alloc>& vector<T, Alloc>::operator=(const vector<T, Alloc>& x){  if (&x != this) {    // 如果x.size() > capacity()那么就需要重新分配内存    // 首先分配内存, 并将容器内原来的元素拷贝到新分配内存中    // 然后析构原容器中元素, 调整内存状态变量    if (x.size() > capacity()) {      iterator tmp = allocate_and_copy(x.end() - x.begin(),                                       x.begin(), x.end());      destroy(start, finish);      deallocate();      start = tmp;      end_of_storage = start + (x.end() - x.begin());    }    else if (size() >= x.size()) {      iterator i = copy(x.begin(), x.end(), begin());      destroy(i, finish);    }    else {      copy(x.begin(), x.begin() + size(), start);      uninitialized_copy(x.begin() + size(), x.end(), finish);    }    finish = start + x.size();  }  return *this;}////////////////////////////////////////////////////////////////////////////////// 提供插入操作//////////////////////////////////////////////////////////////////////////////////                 insert_aux(iterator position, const T& x)//                                   |//                                   |---------------- 容量是否足够?//                                   ↓//              -----------------------------------------//        Yes   |                                       | No//              |                                       |//              ↓                                       |// 从opsition开始, 整体向后移动一个位置                     |// construct(finish, *(finish - 1));                    |// ++finish;                                            |// T x_copy = x;                                        |// copy_backward(position, finish - 2, finish - 1);     |// *position = x_copy;                                  |//                                                      ↓//                            data_allocator::allocate(len);//                            uninitialized_copy(start, position, new_start);//                            construct(new_finish, x);//                            ++new_finish;//                            uninitialized_copy(position, finish, new_finish);//                            destroy(begin(), end());//                            deallocate();////////////////////////////////////////////////////////////////////////////////template <class T, class Alloc>void vector<T, Alloc>::insert_aux(iterator position, const T& x){  if (finish != end_of_storage) {       // 还有剩余内存    construct(finish, *(finish - 1));    ++finish;    T x_copy = x;    copy_backward(position, finish - 2, finish - 1);    *position = x_copy;  }  else {        // 内存不足, 需要重新分配    // 本实作中是按原内存2倍进行重新分配    const size_type old_size = size();    const size_type len = old_size != 0 ? 2 * old_size : 1;    iterator new_start = data_allocator::allocate(len);    iterator new_finish = new_start;    // 将内存重新配置    __STL_TRY {      new_finish = uninitialized_copy(start, position, new_start);      construct(new_finish, x);      ++new_finish;      new_finish = uninitialized_copy(position, finish, new_finish);    }// 分配失败则抛出异常#       ifdef  __STL_USE_EXCEPTIONS    catch(...) {      destroy(new_start, new_finish);      data_allocator::deallocate(new_start, len);      throw;    }#       endif /* __STL_USE_EXCEPTIONS */    // 析构原容器中的对象    destroy(begin(), end());    // 释放原容器分配的内存    deallocate();    // 调整内存指针状态    start = new_start;    finish = new_finish;    end_of_storage = new_start + len;  }}////////////////////////////////////////////////////////////////////////////////// 在指定位置插入n个元素//////////////////////////////////////////////////////////////////////////////////             insert(iterator position, size_type n, const T& x)//                                   |//                                   |---------------- 插入元素个数是否为0?//                                   ↓//              -----------------------------------------//        No    |                                       | Yes//              |                                       |//              |                                       ↓//              |                                    return;//              |----------- 内存是否足够?//              |//      -------------------------------------------------//  Yes |                                               | No//      |                                               |//      |------ (finish - position) > n?                |//      |       分别调整指针                              |//      ↓                                               |//    ----------------------------                      |// No |                          | Yes                  |//    |                          |                      |//    ↓                          ↓                      |// 插入操作, 调整指针           插入操作, 调整指针           |//                                                      ↓//            data_allocator::allocate(len);//            new_finish = uninitialized_copy(start, position, new_start);//            new_finish = uninitialized_fill_n(new_finish, n, x);//            new_finish = uninitialized_copy(position, finish, new_finish);//            destroy(start, finish);//            deallocate();////////////////////////////////////////////////////////////////////////////////template <class T, class Alloc>void vector<T, Alloc>::insert(iterator position, size_type n, const T& x){  // 如果n为0则不进行任何操作  if (n != 0) {    if (size_type(end_of_storage - finish) >= n) {      // 剩下的内存够分配      T x_copy = x;      const size_type elems_after = finish - position;      iterator old_finish = finish;      if (elems_after > n) {        uninitialized_copy(finish - n, finish, finish);        finish += n;        copy_backward(position, old_finish - n, old_finish);        fill(position, position + n, x_copy);      }      else {        uninitialized_fill_n(finish, n - elems_after, x_copy);        finish += n - elems_after;        uninitialized_copy(position, old_finish, finish);        finish += elems_after;        fill(position, old_finish, x_copy);      }    }    else {      // 剩下的内存不够分配, 需要重新分配      const size_type old_size = size();      const size_type len = old_size + max(old_size, n);      iterator new_start = data_allocator::allocate(len);      iterator new_finish = new_start;      __STL_TRY {        new_finish = uninitialized_copy(start, position, new_start);        new_finish = uninitialized_fill_n(new_finish, n, x);        new_finish = uninitialized_copy(position, finish, new_finish);      }#         ifdef  __STL_USE_EXCEPTIONS      catch(...) {        destroy(new_start, new_finish);        data_allocator::deallocate(new_start, len);        throw;      }#         endif /* __STL_USE_EXCEPTIONS */      destroy(start, finish);      deallocate();      start = new_start;      finish = new_finish;      end_of_storage = new_start + len;    }  }}#ifdef __STL_MEMBER_TEMPLATES// 在指定位置插入指定区间的对象template <class T, class Alloc> template <class InputIterator>void vector<T, Alloc>::range_insert(iterator pos,                                    InputIterator first, InputIterator last,                                    input_iterator_tag){  for ( ; first != last; ++first) {    pos = insert(pos, *first);    ++pos;  }}template <class T, class Alloc> template <class ForwardIterator>void vector<T, Alloc>::range_insert(iterator position,                                    ForwardIterator first,                                    ForwardIterator last,                                    forward_iterator_tag){  if (first != last) {    size_type n = 0;    distance(first, last, n);    if (size_type(end_of_storage - finish) >= n) {      const size_type elems_after = finish - position;      iterator old_finish = finish;      if (elems_after > n) {        uninitialized_copy(finish - n, finish, finish);        finish += n;        copy_backward(position, old_finish - n, old_finish);        copy(first, last, position);      }      else {        ForwardIterator mid = first;        advance(mid, elems_after);        uninitialized_copy(mid, last, finish);        finish += n - elems_after;        uninitialized_copy(position, old_finish, finish);        finish += elems_after;        copy(first, mid, position);      }    }    else {      const size_type old_size = size();      const size_type len = old_size + max(old_size, n);      iterator new_start = data_allocator::allocate(len);      iterator new_finish = new_start;      __STL_TRY {        new_finish = uninitialized_copy(start, position, new_start);        new_finish = uninitialized_copy(first, last, new_finish);        new_finish = uninitialized_copy(position, finish, new_finish);      }#         ifdef __STL_USE_EXCEPTIONS      catch(...) {        destroy(new_start, new_finish);        data_allocator::deallocate(new_start, len);        throw;      }#         endif /* __STL_USE_EXCEPTIONS */      destroy(start, finish);      deallocate();      start = new_start;      finish = new_finish;      end_of_storage = new_start + len;    }  }}#else /* __STL_MEMBER_TEMPLATES */template <class T, class Alloc>void vector<T, Alloc>::insert(iterator position,                              const_iterator first,                              const_iterator last) {  if (first != last) {    size_type n = 0;    distance(first, last, n);    if (size_type(end_of_storage - finish) >= n) {      const size_type elems_after = finish - position;      iterator old_finish = finish;      if (elems_after > n) {        uninitialized_copy(finish - n, finish, finish);        finish += n;        copy_backward(position, old_finish - n, old_finish);        copy(first, last, position);      }      else {        uninitialized_copy(first + elems_after, last, finish);        finish += n - elems_after;        uninitialized_copy(position, old_finish, finish);        finish += elems_after;        copy(first, first + elems_after, position);      }    }    else {      const size_type old_size = size();      const size_type len = old_size + max(old_size, n);      iterator new_start = data_allocator::allocate(len);      iterator new_finish = new_start;      __STL_TRY {        new_finish = uninitialized_copy(start, position, new_start);        new_finish = uninitialized_copy(first, last, new_finish);        new_finish = uninitialized_copy(position, finish, new_finish);      }#         ifdef __STL_USE_EXCEPTIONS      catch(...) {        destroy(new_start, new_finish);        data_allocator::deallocate(new_start, len);        throw;      }#         endif /* __STL_USE_EXCEPTIONS */      destroy(start, finish);      deallocate();      start = new_start;      finish = new_finish;      end_of_storage = new_start + len;    }  }}#endif /* __STL_MEMBER_TEMPLATES */#if defined(__sgi) && !defined(__GNUC__) && (_MIPS_SIM != _MIPS_SIM_ABI32)#pragma reset woff 1174#endif__STL_END_NAMESPACE#endif /* __SGI_STL_INTERNAL_VECTOR_H */// Local Variables:// mode:C++// End:

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