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operator== (<iterator>)

Tests if the iterator object on the left side of the operator is equal to the iterator object on the right side.

template<class RandomIterator> 
   bool operator==( 
      const reverse_iterator<RandomIterator>& _Left, 
      const reverse_iterator<RandomIterator>& _Right 
   ); 
template<class Type, class CharType, class Traits, class Distance> 
   bool operator==( 
      const istream_iterator<Type, CharType, Traits, Distance>& _Left, 
      const istream_iterator<Type, CharType, Traits, Distance>& _Right 
   ); 
template<class CharType, class Tr> 
   bool operator==( 
      const istreambuf_iterator<CharType, Traits>& _Left, 
      const istreambuf_iterator<CharType, Traits>& _Right 
);

Parameters

  • _Left
    An object of type iterator.

  • _Right
    An object of type iterator.

Return Value

true if the iterator objects are equal; false if the iterator objects are not equal.

Remarks

One iterator object is equal to another if they address the same elements in a container. If two iterators point to different elements in a container, then they are not equal.

Example

// iterator_op_eq.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;

   // Initializing reverse_iterators to the last element
   vector <int>::reverse_iterator rVPOS1 = vec.rbegin ( ), 
           rVPOS2 = vec.rbegin ( );
   
   cout << "The iterator rVPOS1 initially points to the first "
        << "element\n in the reversed sequence: "
        << *rVPOS1 << "." << endl;

   if ( rVPOS1 == rVPOS2 )
      cout << "The iterators are equal." << endl;
   else
      cout << "The iterators are not equal." << endl;

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

   if ( rVPOS1 == rVPOS2 )
      cout << "The iterators are equal." << endl;
   else
      cout << "The iterators are not equal." << endl;
}

The vector vec is: ( 2 4 6 8 10 ). The iterator rVPOS1 initially points to the first element in the reversed sequence: 10. The iterators are equal. The iterator rVPOS1 now points to the second element in the reversed sequence: 8. The iterators are not equal.

Requirements

Header: <iterator>

Namespace: std

See Also

Reference

Standard Template Library

Other Resources

<iterator> Members