<unordered_map> operators

Visual Studio 2015
 

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operator!=](#operator_neq)|operator==|operator!=|operator==|

Tests whether the unordered_map object on the left side of the operator is not equal to the unordered_map object on the right side.

bool operator!=(const unordered_map <Key, Type, Hash, Pred, Allocator>& left, const unordered_map <Key, Type, Hash, Pred, Allocator>& right);

Parameters

left
An object of type unordered_map.

right
An object of type unordered_map.

Return Value

true if the unordered_maps are not equal; false if they are equal.

Remarks

The comparison between unordered_map objects is not affected by the arbitrary order in which they store their elements. Two unordered_maps are equal if they have the same number of elements and the elements in one container are a permutation of the elements in the other container. Otherwise, they are unequal.

Example

// unordered_map_op_ne.cpp  
// compile by using: cl.exe /EHsc /nologo /W4 /MTd   
#include <unordered_map>  
#include <iostream>  
#include <ios>  
  
int main( )  
{  
   using namespace std;  
   unordered_map<int, int> um1, um2, um3;  
  
   for ( int i = 0 ; i < 3 ; ++i ) {  
      um1.insert( make_pair( i+1, i ) );  
      um1.insert( make_pair( i, i ) );  
  
      um2.insert( make_pair( i, i+1 ) );  
      um2.insert( make_pair( i, i ) );  
  
      um3.insert( make_pair( i, i ) );  
      um3.insert( make_pair( i+1, i ) );  
   }  
  
   cout << boolalpha;  
   cout << "um1 != um2: " << (um1 != um2) << endl;   
   cout << "um1 != um3: " << (um1 != um3) << endl;   
   cout << "um2 != um3: " << (um2 != um3) << endl;   
}  
  

Output:

um1 != um2: true

um1 != um3: false

um2 != um3: true

Tests whether the unordered_map object on the left side of the operator is equal to the unordered_map object on the right side.

bool operator==(const unordered_map <Key, Type, Hash, Pred, Allocator>& left, const unordered_map <Key, Type, Hash, Pred, Allocator>& right);

Parameters

left
An object of type unordered_map.

right
An object of type unordered_map.

Return Value

true if the unordered_maps are equal; false if they are not equal.

Remarks

The comparison between unordered_map objects is not affected by the arbitrary order in which they store their elements. Two unordered_maps are equal if they have the same number of elements and the elements in one container are a permutation of the elements in the other container. Otherwise, they are unequal.

Example

// unordered_map_op_eq.cpp  
// compile by using: cl.exe /EHsc /nologo /W4 /MTd   
#include <unordered_map>  
#include <iostream>  
#include <ios>  
  
int main( )  
{  
   using namespace std;  
   unordered_map<int, int> um1, um2, um3;  
  
   for ( int i = 0 ; i < 3 ; ++i ) {  
      um1.insert( make_pair( i+1, i ) );  
      um1.insert( make_pair( i, i ) );  
  
      um2.insert( make_pair( i, i+1 ) );  
      um2.insert( make_pair( i, i ) );  
  
      um3.insert( make_pair( i, i ) );  
      um3.insert( make_pair( i+1, i ) );  
   }  
  
   cout << boolalpha;  
   cout << "um1 == um2: " << (um1 == um2) << endl;   
   cout << "um1 == um3: " << (um1 == um3) << endl;   
   cout << "um2 == um3: " << (um2 == um3) << endl;   
}  
  

Output:

um1 == um2: false

um1 == um3: true

um2 == um3: false

Tests whether the unordered_multimap object on the left side of the operator is not equal to the unordered_multimap object on the right side.

bool operator!=(const unordered_multimap <Key, Type, Hash, Pred, Allocator>& left, const unordered_multimap <Key, Type, Hash, Pred, Allocator>& right);

Parameters

left
An object of type unordered_multimap.

right
An object of type unordered_multimap.

Return Value

true if the unordered_multimaps are not equal; false if they are equal.

Remarks

The comparison between unordered_multimap objects is not affected by the arbitrary order in which they store their elements. Two unordered_multimaps are equal if they have the same number of elements and the elements in one container are a permutation of the elements in the other container. Otherwise, they are not equal.

Example

// unordered_multimap_op_ne.cpp  
// compile by using: cl.exe /EHsc /nologo /W4 /MTd   
#include <unordered_map>  
#include <iostream>  
#include <ios>  
  
int main( )  
{  
   using namespace std;  
   unordered_multimap<int, int> um1, um2, um3;  
  
   for ( int i = 0 ; i < 3 ; ++i ) {  
      um1.insert( make_pair( i, i ) );  
      um1.insert( make_pair( i, i ) );  
  
      um2.insert( make_pair( i, i ) );  
      um2.insert( make_pair( i, i ) );  
      um2.insert( make_pair( i, i ) );  
  
      um3.insert( make_pair( i, i ) );  
      um3.insert( make_pair( i, i ) );  
   }  
  
   cout << boolalpha;  
   cout << "um1 != um2: " << (um1 != um2) << endl;   
   cout << "um1 != um3: " << (um1 != um3) << endl;   
   cout << "um2 != um3: " << (um2 != um3) << endl;   
}  
  

Output:

um1 != um2: true

um1 != um3: false

um2 != um3: true

Tests whether the unordered_multimap object on the left side of the operator is equal to the unordered_multimap object on the right side.

bool operator==(const unordered_multimap <Key, Type, Hash, Pred, Allocator>& left, const unordered_multimap <Key, Type, Hash, Pred, Allocator>& right);

Parameters

left
An object of type unordered_multimap.

right
An object of type unordered_multimap.

Return Value

true if the unordered_multimaps are equal; false if they are not equal.

Remarks

The comparison between unordered_multimap objects is not affected by the arbitrary order in which they store their elements. Two unordered_multimaps are equal if they have the same number of elements and the elements in one container are a permutation of the elements in the other container. Otherwise, they are unequal.

Example

  
// unordered_multimap_op_eq.cpp  
// compile by using: cl.exe /EHsc /nologo /W4 /MTd  
#include <unordered_map>  
#include <iostream>  
#include <ios>  
  
int main( )  
{  
   using namespace std;  
   unordered_multimap<int, int> um1, um2, um3;  
  
   for ( int i = 0 ; i < 3 ; ++i ) {  
      um1.insert( make_pair( i, i ) );  
      um1.insert( make_pair( i, i ) );  
  
      um2.insert( make_pair( i, i ) );  
      um2.insert( make_pair( i, i ) );  
      um2.insert( make_pair( i, i ) );  
  
      um3.insert( make_pair( i, i ) );  
      um3.insert( make_pair( i, i ) );  
   }  
  
   cout << boolalpha;  
   cout << "um1 == um2: " << (um1 == um2) << endl;   
   cout << "um1 == um3: " << (um1 == um3) << endl;   
   cout << "um2 == um3: " << (um2 == um3) << endl;   
}  
  

Output:

um1 == um2: false

um1 == um3: true

um2 == um3: false

<unordered_map>

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