《STL源码剖析》-- stl_vector.h

《STL源码剖析》-- stl_vector.h

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STL源码剖析 2011-07-28 19:45
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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_ORDER

template <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: