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
Requirements
Header: <unordered_map>
Namespace: std