reverse_iterator::operator--

會 reverse_iterator 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 reverse_iterator predecremented 第二， postdecrement 運算子，傳回遞減 reverse_iterator的複本。

備註

這個成員函式，如果 reverse_iterator 符合雙向 Iterator，需求可能只能透過取得。

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;
}

需求

標頭：<迭代器>

命名空間: std

請參閱

參考

reverse_iterator 類別

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