operator- (<iterator>)

从另一个迭代器中减去一迭代器并返回该差异。

template<class RandomIterator1, class RandomIterator2>
    Tdiff operator-(
        const move_iterator<RandomIterator1>& _Left,
        const move_iterator<RandomIterator2>& _Right
    );
template<class RandomIterator1, class RandomIterator2>
    Tdiff operator-(
        const reverse_iterator<RandomIterator1>& _Left,
        const reverse_iterator<RandomIterator2>& _Right
);

参数

• _Left
  迭代器。

• _Right
  迭代器。

返回值

两个迭代器.之间的差异

备注

第一个模板运算符返回 _Left.base() - _Right.base()。

第二个模板运算符返回 _Right.current - _Left.current。

Tdiff 确定返回表达式的类型。 否则为 RandomIterator1::difference_type。

示例

// 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 = 0 ; i < 6 ; ++i )  
   {
      vec.push_back ( 2 * i );
   }
   
   vector <int>::iterator vIter;

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

   vector <int>::reverse_iterator rVPOS1 = vec.rbegin ( ), 
          rVPOS2 = vec.rbegin ( );
   
   cout << "The iterators rVPOS1 & rVPOS2 initially point to "
        << "the first element\n in the reversed sequence: "
        << *rVPOS1 << "." << endl;

   for (i = 1; i < 5; ++i)  
   {
      rVPOS2++;
   }
   cout << "The iterator rVPOS2 now points to the fifth "
        << "element\n in the reversed sequence: "
        << *rVPOS2 << "." << endl;

   vector<int>::difference_type diff = rVPOS2 - rVPOS1;
   cout << "The difference: rVPOS2 - rVPOS1= "
        << diff << "." << endl;
}

要求

头文件： <iterator>

命名空间: std

请参见

参考

标准模板库