reverse_iterator 類別

類別範本是反覆運算器配接器，描述反向反覆運算器物件，其行為就像隨機存取或雙向反覆運算器一樣，只會反向運作。 它啟用範圍的向後周遊。

語法

template <class RandomIterator>
class reverse_iterator

參數

RandomIterator 代表要調整為反向運作的反覆運算器類型。

備註

現有的 C++ 標準程式庫容器也會定義 reverse_iterator 和 const_reverse_iterator 類型，並且具有可傳回反向迭代器的成員函式 rbegin 和 rend。 這些迭代器有覆寫語意。 配 reverse_iterator 接器會補充這項功能，因為它提供插入語意，也可以與數據流搭配使用。

reverse_iterator需要雙向反覆運算器的 ，不得呼叫任何只能搭配隨機存取反覆運算器使用的成員函operator+=式 、operator+、、 operator-=operator-或 operator[]。

反覆運算器的範圍是 [first， last），其中左邊的方括弧表示包含第一個，右邊的括號表示包含最多但排除最後一個專案。 相同的元素會包含在反向序列 [rev - first， rev - last） 中，因此，如果 last 是序列中的一個過去結束元素，則反轉序列中的第一個元素 rev - 會指向 *（last - 1）。 將所有反向迭代器關聯至其基礎迭代器的識別為：

&*（reverse_iterator （i）） == &*（i - 1）。

實際上，這表示在反向序列中 reverse_iterator 會參考迭代器在原始序列中所參考項目之外 (右側) 一個位置的項目。 因此，如果迭代器定址序列 (2, 4, 6, 8) 中的項目 6，則 reverse_iterator 會定址反向序列 (8, 6, 4, 2) 中的項目 4。

建構函式

建構函式	描述
reverse_iterator	從基底迭代器建構預設的 reverse_iterator 或 reverse_iterator。

Typedefs

類型名稱	描述
difference_type	類型，提供兩個參考同一容器內項目的 reverse_iterator 之間的差異。
iterator_type	類型，提供 reverse_iterator 的基礎迭代器。
pointer	類型，提供指向 reverse_iterator 定址的項目之指標。
reference	類型，提供指向 reverse_iterator 定址的項目之參考。

成員函式

成員函數	描述
base	從其 reverse_iterator 復原基礎迭代器。

操作員

運算子	描述
operator_star	傳回 reverse_iterator 定址的項目。
operator+	將位移新增至迭代器，並傳回新的 reverse_iterator，定址在新的位移位置中插入的項目。
operator++	遞增 reverse_iterator 至下一個項目。
operator+=	加入 reverse_iterator 的指定位移。
operator-	從 reverse_iterator 減去位移並傳回 reverse_iterator，定址在位移位置上的項目。
算子--	遞減 reverse_iterator 至上一個項目。
operator-=	從 reverse_iterator 減去指定位移。
operator->	傳回由 reverse_iterator 定址的項目之指標。
operator[]	以指定的位置數目，從 reverse_iterator 定址的項目傳回項目位移的參考。

需求

Header：<iterator>

命名空間：std

reverse_iterator：：base

從其 reverse_iterator 復原基礎迭代器。

RandomIterator base() const;

傳回值

構成 reverse_iterator 基礎的迭代器。

備註

將所有反向迭代器關聯至其基礎迭代器的識別為：

&*（reverse_iterator i）） == &*（i - 1）。

實際上，這表示在反向序列中，reverse_iterator 將參考迭代器在原始序列中所參考項目之外 (右側) 某個位置的項目。 因此，如果迭代器定址序列 (2, 4, 6, 8) 中的項目 6，則 reverse_iterator 會定址反向序列 (8, 6, 4, 2) 中的項目 4。

範例

// reverse_iterator_base.cpp
// compile with: /EHsc
#include <iterator>
#include <algorithm>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for ( i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 2 * i );
   }

   vector <int>::iterator vIter;
   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin ( ) ; vIter != vec.end ( ); vIter++ )
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   vector <int>::iterator pos, bpos;
   pos = find ( vec.begin ( ), vec.end ( ), 6 );
   cout << "The iterator pos points to: " << *pos << "." << endl;

   typedef reverse_iterator<vector<int>::iterator>::iterator_type it_vec_int_type;

   reverse_iterator<it_vec_int_type> rpos ( pos );
   cout << "The reverse_iterator rpos points to: " << *rpos
        << "." << endl;

   bpos = rpos.base ( );
   cout << "The iterator underlying rpos is bpos & it points to: "
        << *bpos << "." << endl;
}

reverse_iterator：:d ifference_type

類型，提供兩個參考同一容器內項目的 reverse_iterator 之間的差異。

typedef typename iterator_traits<RandomIterator>::difference_type  difference_type;

備註

reverse_iterator 差異類型與迭代器差異類型相同。

類型是迭代器特性 typename iterator_traits<RandomIterator>::pointer 的同義字。

範例

如需如何宣告和使用 difference_type的範例，請參閱 reverse_iterator::operator[] 。

reverse_iterator：：iterator_type

類型，提供 reverse_iterator 的基礎迭代器。

typedef RandomIterator iterator_type;

備註

此類型是範本參數 Iterator的同義字。

範例

如需如何宣告及使用 iterator_type 的範例，請參閱 reverse_iterator::base。

reverse_iterator：：operator*

傳回 reverse_iterator 定址的項目。

reference operator*() const;

傳回值

reverse_iterator 所定址的項目值。

備註

運算符會傳回 *（ 目前 - 1）。

範例

// reverse_iterator_op_ref.cpp
// compile with: /EHsc
#include <iterator>
#include <algorithm>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for (i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 2 * i );
   }

   vector <int>::iterator vIter;
   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin ( ) ; vIter != vec.end ( ); vIter++ )
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   vector <int>::iterator pos, bpos;
   pos = find ( vec.begin ( ), vec.end ( ), 6 );

   // Declare a difference type for a parameter
   // declare a reference return type
   reverse_iterator<vector<int>::iterator>::reference refpos = *pos;
   cout << "The iterator pos points to: " << refpos << "." << endl;
}

reverse_iterator：：operator+

將位移新增至迭代器，並傳回新的 reverse_iterator，定址在新的位移位置中插入的項目。

reverse_iterator<RandomIterator> operator+(difference_type Off) const;

參數

關閉
要加入至反向迭代器的位移。

傳回值

為位移項目定址的 reverse_iterator。

備註

唯有在 reverse_iterator 滿足隨機存取迭代器的需求時，才能使用此成員函式。

範例

// reverse_iterator_op_add.cpp
// compile with: /EHsc
#include <iterator>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for (i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 2 * i );
   }

   vector <int>::iterator vIter;
   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin( ) ; vIter != vec.end( ); vIter++)
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   // Initializing reverse_iterators to the first element
   vector <int>::reverse_iterator rVPOS1 = vec.rbegin ( );

   cout << "The iterator rVPOS1 initially points to the first "
        << "element\n in the reversed sequence: "
        << *rVPOS1 << "." << endl;

   vector <int>::reverse_iterator rVPOS2 =rVPOS1 + 2; // offset added
   cout << "After the +2 offset, the iterator rVPOS2 points\n"
        << " to the 3rd element in the reversed sequence: "
        << *rVPOS2 << "." << endl;
}

The vector vec is: ( 2 4 6 8 10 ).
The vector vec reversed is: ( 10 8 6 4 2 ).
The iterator rVPOS1 initially points to the first element
in the reversed sequence: 10.
After the +2 offset, the iterator rVPOS2 points
to the 3rd element in the reversed sequence: 6.

reverse_iterator：：operator++

將 reverse_iterator 遞增至上一個項目。

reverse_iterator<RandomIterator>& operator++();
reverse_iterator<RandomIterator> operator++(int);

傳回值

第一個運算子會傳回前置遞增的 reverse_iterator，而第二個後置遞增運算子會傳回遞增的 reverse_iterator 複本。

備註

唯有在 reverse_iterator 滿足雙向迭代器的需求時，才能使用此成員函式。

範例

// reverse_iterator_op_incr.cpp
// compile with: /EHsc
#include <iterator>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for ( i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 2 * i - 1 );
   }

   vector <int>::iterator vIter;
   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin( ) ; vIter != vec.end( ); vIter++)
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   // Initializing reverse_iterators to the last element
   vector <int>::reverse_iterator rVPOS1 = vec.rbegin( );

   cout << "The iterator rVPOS1 initially points to the first "
        << "element\n in the reversed sequence: "
        << *rVPOS1 << "." << endl;

   rVPOS1++;  // postincrement, preincrement: ++rVPSO1

   cout << "After incrementing, the iterator rVPOS1 points\n"
        << " to the second element in the reversed sequence: "
        << *rVPOS1 << "." << endl;
}

The vector vec is: ( 1 3 5 7 9 ).
The vector vec reversed is: ( 9 7 5 3 1 ).
The iterator rVPOS1 initially points to the first element
in the reversed sequence: 9.
After incrementing, the iterator rVPOS1 points
to the second element in the reversed sequence: 7.

reverse_iterator：：operator+=

加入 reverse_iterator 的指定位移。

reverse_iterator<RandomIterator>& operator+=(difference_type Off);

參數

關閉
要遞增迭代器的位移。

傳回值

由 reverse_iterator 定址之項目的參考。

範例

// reverse_iterator_op_addoff.cpp
// compile with: /EHsc
#include <iterator>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for (i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 2 * i );
   }

   vector <int>::iterator vIter;

   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin( ) ; vIter != vec.end( ); vIter++)
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   // Initializing reverse_iterators to the last element
   vector <int>::reverse_iterator rVPOS1 = vec.rbegin ( );

   cout << "The iterator rVPOS1 initially points to the first "
        << "element\n in the reversed sequence: "
        << *rVPOS1 << "." << endl;

   rVPOS1+=2;   // addition of an offset
   cout << "After the +2 offset, the iterator rVPOS1 now points\n"
        << " to the third element in the reversed sequence: "
        << *rVPOS1 << "." << endl;
}

The vector vec is: ( 2 4 6 8 10 ).
The vector vec reversed is: ( 10 8 6 4 2 ).
The iterator rVPOS1 initially points to the first element
in the reversed sequence: 10.
After the +2 offset, the iterator rVPOS1 now points
to the third element in the reversed sequence: 6.

reverse_iterator：：operator-

從 reverse_iterator 減去位移並傳回 reverse_iterator，定址在位移位置上的項目。

reverse_iterator<RandomIterator> operator-(difference_type Off) const;

參數

關閉
要從 reverse_iterator 中減去的位移。

傳回值

為位移項目定址的 reverse_iterator。

備註

唯有在 reverse_iterator 滿足隨機存取迭代器的需求時，才能使用此成員函式。

範例

// reverse_iterator_op_sub.cpp
// compile with: /EHsc
#include <iterator>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for ( i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 3 * i );
   }

   vector <int>::iterator vIter;

   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin( ) ; vIter != vec.end( ); vIter++)
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   // Initializing reverse_iterators to the first element
   vector <int>::reverse_iterator rVPOS1 = vec.rend ( ) - 1;

   cout << "The iterator rVPOS1 initially points to the last "
        << "element\n in the reversed sequence: "
        << *rVPOS1 << "." << endl;

   vector <int>::reverse_iterator rVPOS2 =rVPOS1 - 2; // offset subtracted
   cout << "After the -2 offset, the iterator rVPOS2 points\n"
        << " to the 2nd element from the last in the reversed sequence: "
        << *rVPOS2 << "." << endl;
}

The vector vec is: ( 3 6 9 12 15 ).
The vector vec reversed is: ( 15 12 9 6 3 ).
The iterator rVPOS1 initially points to the last element
in the reversed sequence: 3.
After the -2 offset, the iterator rVPOS2 points
to the 2nd element from the last in the reversed sequence: 9.

reverse_iterator：：operator--

將 reverse_iterator 遞減至上一個項目。

reverse_iterator<RandomIterator>& operator--();
reverse_iterator<RandomIterator> operator--(int);

傳回值

第一個運算子會傳回前置遞減的 reverse_iterator，而第二個後置遞減運算子會傳回遞減的 reverse_iterator 複本。

備註

唯有在 reverse_iterator 滿足雙向迭代器的需求時，才能使用此成員函式。

範例

// reverse_iterator_op_decr.cpp
// compile with: /EHsc
#include <iterator>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for (i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 2 * i - 1 );
   }

   vector <int>::iterator vIter;

   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin( ) ; vIter != vec.end( ); vIter++)
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   // Initializing reverse_iterators to the first element
   vector <int>::reverse_iterator rVPOS1 = vec.rend ( ) - 1;

   cout << "The iterator rVPOS1 initially points to the last "
        << "element\n in the reversed sequence: "
        << *rVPOS1 << "." << endl;
   rVPOS1--;  // postdecrement, predecrement: --rVPSO1

   cout << "After the decrement, the iterator rVPOS1 points\n"
        << " to the next-to-last element in the reversed sequence: "
        << *rVPOS1 << "." << endl;
}

The vector vec is: ( 1 3 5 7 9 ).
The vector vec reversed is: ( 9 7 5 3 1 ).
The iterator rVPOS1 initially points to the last element
in the reversed sequence: 1.
After the decrement, the iterator rVPOS1 points
to the next-to-last element in the reversed sequence: 3.

reverse_iterator：：operator-=

從 reverse_iterator 減去指定位移。

reverse_iterator<RandomIterator>& operator-=(difference_type Off);

參數

關閉
要從 reverse_iterator 中減去的位移。

備註

唯有在 reverse_iterator 滿足隨機存取迭代器的需求時，才能使用此成員函式。

運算子會 評估目前的 + Off ，然後傳 *this回 。

範例

// reverse_iterator_op_suboff.cpp
// compile with: /EHsc
#include <iterator>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for (i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 3 * i );
   }

   vector <int>::iterator vIter;

   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin( ) ; vIter != vec.end( ); vIter++)
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   // Initializing reverse_iterators to the first element
   vector <int>::reverse_iterator rVPOS1 = vec.rend ( ) - 1;

   cout << "The iterator rVPOS1 initially points to the last "
        << "element\n in the reversed sequence: "
        << *rVPOS1 << "." << endl;

   rVPOS1-=2;      // Subtraction of an offset
   cout << "After the -2 offset, the iterator rVPOS1 now points\n"
        << " to the 2nd element from the last in the reversed sequence: "
        << *rVPOS1 << "." << endl;
}

The vector vec is: ( 3 6 9 12 15 ).
The vector vec reversed is: ( 15 12 9 6 3 ).
The iterator rVPOS1 initially points to the last element
in the reversed sequence: 3.
After the -2 offset, the iterator rVPOS1 now points
to the 2nd element from the last in the reversed sequence: 9.

reverse_iterator::operator->

傳回由 reverse_iterator 定址的項目之指標。

pointer operator->() const;

傳回值

由 reverse_iterator 定址之項目的指標。

備註

第一個運算子會傳回 &**this。

範例

// reverse_iterator_ptrto.cpp
// compile with: /EHsc
#include <iterator>
#include <algorithm>
#include <vector>
#include <utility>
#include <iostream>

int main( )
{
   using namespace std;

   typedef vector<pair<int,int> > pVector;
   pVector vec;
   vec.push_back(pVector::value_type(1,2));
   vec.push_back(pVector::value_type(3,4));
   vec.push_back(pVector::value_type(5,6));

   pVector::iterator pvIter;
   cout << "The vector vec of integer pairs is:\n( ";
   for ( pvIter = vec.begin ( ) ; pvIter != vec.end ( ); pvIter++)
      cout << "( " << pvIter -> first << ", " << pvIter -> second << ") ";
   cout << ")" << endl << endl;

   pVector::reverse_iterator rpvIter;
   cout << "The vector vec reversed is:\n( ";
   for ( rpvIter = vec.rbegin( ) ; rpvIter != vec.rend( ); rpvIter++ )
      cout << "( " << rpvIter -> first << ", " << rpvIter -> second << ") ";
   cout << ")" << endl << endl;

   pVector::iterator pos = vec.begin ( );
   pos++;
   cout << "The iterator pos points to:\n( " << pos -> first << ", "
   << pos -> second << " )" << endl << endl;

   pVector::reverse_iterator rpos (pos);

   // Use operator -> with return type: why type int and not int*
   int fint = rpos -> first;
   int sint = rpos -> second;

   cout << "The reverse_iterator rpos points to:\n( " << fint << ", "
   << sint << " )" << endl;
}

The vector vec of integer pairs is:
( ( 1, 2) ( 3, 4) ( 5, 6) )

The vector vec reversed is:
( ( 5, 6) ( 3, 4) ( 1, 2) )

The iterator pos points to:
( 3, 4 )

The reverse_iterator rpos points to:
( 1, 2 )

reverse_iterator：：operator[]

以指定的位置數目，從 reverse_iterator 定址的項目傳回項目位移的參考。

reference operator[](difference_type Off) const;

參數

關閉
reverse_iterator 位址的位移。

傳回值

項目位移的參考。

備註

運算子會傳*回 （ + *thisOff 。

範例

// reverse_iterator_ret_ref.cpp
// compile with: /EHsc
#include <iterator>
#include <algorithm>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for (i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( 2 * i );
   }

   vector <int>::iterator vIter;
   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin ( ) ; vIter != vec.end ( ); vIter++ )
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   vector <int>::iterator pos;
   pos = find ( vec.begin ( ), vec.end ( ), 8 );
   reverse_iterator<vector<int>::iterator> rpos ( pos );

   // Declare a difference type for a parameter
   reverse_iterator<vector<int>::iterator>::difference_type diff = 2;

   cout << "The iterator pos points to: " << *pos << "." << endl;
   cout << "The iterator rpos points to: " << *rpos << "." << endl;

   // Declare a reference return type & use operator[]
   reverse_iterator<vector<int>::iterator>::reference refrpos = rpos [diff];
   cout << "The iterator rpos now points to: " << refrpos << "." << endl;
}

The vector vec is: ( 2 4 6 8 10 ).
The vector vec reversed is: ( 10 8 6 4 2 ).
The iterator pos points to: 8.
The iterator rpos points to: 6.
The iterator rpos now points to: 2.

reverse_iterator：:p ointer

類型，提供指向 reverse_iterator 定址的項目之指標。

typedef typename iterator_traits<RandomIterator>::pointer pointer;

備註

類型是迭代器特性 typename iterator_traits<RandomIterator>::pointer 的同義字。

範例

// reverse_iterator_pointer.cpp
// compile with: /EHsc
#include <iterator>
#include <algorithm>
#include <vector>
#include <utility>
#include <iostream>

int main( )
{
   using namespace std;

   typedef vector<pair<int,int> > pVector;
   pVector vec;
   vec.push_back( pVector::value_type( 1,2 ) );
   vec.push_back( pVector::value_type( 3,4 ) );
   vec.push_back( pVector::value_type( 5,6 ) );

   pVector::iterator pvIter;
   cout << "The vector vec of integer pairs is:\n" << "( ";
   for ( pvIter = vec.begin ( ) ; pvIter != vec.end ( ); pvIter++)
      cout << "( " << pvIter -> first << ", " << pvIter -> second << ") ";
   cout << ")" << endl;

   pVector::reverse_iterator rpvIter;
   cout << "\nThe vector vec reversed is:\n" << "( ";
   for ( rpvIter = vec.rbegin( ) ; rpvIter != vec.rend( ); rpvIter++)
      cout << "( " << rpvIter -> first << ", " << rpvIter -> second << ") ";
   cout << ")" << endl;

   pVector::iterator pos = vec.begin ( );
   pos++;
   cout << "\nThe iterator pos points to:\n"
        << "( " << pos -> first << ", "
        << pos -> second << " )" << endl;

   pVector::reverse_iterator rpos (pos);
   cout << "\nThe iterator rpos points to:\n"
        << "( " << rpos -> first << ", "
        << rpos -> second << " )" << endl;
}

The vector vec of integer pairs is:
( ( 1, 2) ( 3, 4) ( 5, 6) )

The vector vec reversed is:
( ( 5, 6) ( 3, 4) ( 1, 2) )

The iterator pos points to:
( 3, 4 )

The iterator rpos points to:
( 1, 2 )

reverse_iterator：：reference

類型，提供指向 reverse_iterator 定址之項目的參考。

typedef typename iterator_traits<RandomIterator>::reference reference;

備註

此類型與反覆運算器特性類型名稱 iterator_traits<RandomIterator>::reference同義。

範例

如需如何宣告和使用 reference的範例，請參閱reverse_iterator::operator[]或reverse_iterator：：operator* 。

reverse_iterator：：reverse_iterator

從基底迭代器建構預設的 reverse_iterator 或 reverse_iterator。

reverse_iterator();
explicit reverse_iterator(RandomIterator right);

template <class Type>
reverse_iterator(const reverse_iterator<Type>& right);

參數

right
要調整為 reverse_iterator 的迭代器。

傳回值

調整基礎迭代器的預設 reverse_iterator 或 reverse_iterator。

備註

將所有反向迭代器關聯至其基礎迭代器的識別為：

&*(reverse_iterator (i)) == &*(i-1).

實際上，這表示在反向序列中 reverse_iterator 會參考迭代器在原始序列中所參考項目之外 (右側) 一個位置的項目。 因此，如果迭代器定址序列 (2, 4, 6, 8) 中的項目 6，則 reverse_iterator 會定址反向序列 (8, 6, 4, 2) 中的項目 4。

範例

// reverse_iterator_reverse_iterator.cpp
// compile with: /EHsc
#include <iterator>
#include <algorithm>
#include <vector>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   vector<int> vec;
   for ( i = 1 ; i < 6 ; ++i )
   {
      vec.push_back ( i );
   }

   vector <int>::iterator vIter;
   cout << "The vector vec is: ( ";
   for ( vIter = vec.begin ( ) ; vIter != vec.end ( ); vIter++)
      cout << *vIter << " ";
   cout << ")." << endl;

   vector <int>::reverse_iterator rvIter;
   cout << "The vector vec reversed is: ( ";
   for ( rvIter = vec.rbegin( ) ; rvIter != vec.rend( ); rvIter++)
      cout << *rvIter << " ";
   cout << ")." << endl;

   vector <int>::iterator pos;
   pos = find ( vec.begin ( ), vec.end ( ), 4 );
   cout << "The iterator pos = " << *pos << "." << endl;

   vector <int>::reverse_iterator rpos ( pos );
   cout << "The reverse_iterator rpos = " << *rpos
        << "." << endl;
}

另請參閱

<iterator>
C++ 標準程式庫中的執行緒安全
C++ 標準程式庫參考