<unordered_set> operators

Visual Studio 2015
 

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at <unordered_set> operators.

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

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

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

Parameters

left
An object of type unordered_set.

right
An object of type unordered_set.

Return Value

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

Remarks

The comparison between unordered_set objects is not affected by the arbitrary order in which they store their elements. Two unordered_sets 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

C++
Copy 
  
// unordered_set_ne.cpp   
// compile by using: cl.exe /EHsc /nologo /W4 /MTd   
#include <unordered_set>   
#include <iostream>   
#include <ios>  
  
int main()   
{   
    using namespace std;  
  
    unordered_set<char> c1, c2, c3;  
  
    c1.insert('a');   
    c1.insert('b');   
    c1.insert('c');   
  
    c2.insert('c');   
    c2.insert('a');   
    c2.insert('d');   
  
    c3.insert('c');   
    c3.insert('a');   
    c3.insert('b');   
  
   cout << boolalpha;  
   cout << "c1 != c2: " << (c1 != c2) << endl;   
   cout << "c1 != c3: " << (c1 != c3) << endl;   
   cout << "c2 != c3: " << (c2 != c3) << endl;   
  
    return (0);   
}

Output:

c1 != c2: true

c1 != c3: false

c2 != c3: true

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

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

Parameters

left
An object of type unordered_set.

right
An object of type unordered_set.

Return Value

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

Remarks

The comparison between unordered_set objects is not affected by the arbitrary order in which they store their elements. Two unordered_sets 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

C++
Copy 
  
// unordered_set_eq.cpp   
// compile by using: cl.exe /EHsc /nologo /W4 /MTd   
#include <unordered_set>   
#include <iostream>   
#include <ios>  
  
int main()   
{   
    using namespace std;  
  
    unordered_set<char> c1, c2, c3;  
  
    c1.insert('a');   
    c1.insert('b');   
    c1.insert('c');   
  
    c2.insert('c');   
    c2.insert('a');   
    c2.insert('d');   
  
    c3.insert('c');   
    c3.insert('a');   
    c3.insert('b');   
  
   cout << boolalpha;  
   cout << "c1 == c2: " << (c1 == c2) << endl;   
   cout << "c1 == c3: " << (c1 == c3) << endl;   
   cout << "c2 == c3: " << (c2 == c3) << endl;   
  
    return (0);   
}

Output:

c1 == c2: false

c1 == c3: true

c2 == c3: false

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

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

Parameters

left
An object of type unordered_multiset.

right
An object of type unordered_multiset.

Return Value

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

Remarks

The comparison between unordered_multiset objects is not affected by the arbitrary order in which they store their elements. Two unordered_multisets 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

C++
Copy 
// unordered_multiset_ne.cpp   
// compile by using: cl.exe /EHsc /nologo /W4 /MTd   
#include <unordered_set>   
#include <iostream>   
#include <ios>  
  
int main()   
{   
    using namespace std;  
  
    unordered_multiset<char> c1, c2, c3;  
  
    c1.insert('a');   
    c1.insert('b');   
    c1.insert('c');   
    c1.insert('c');   
  
    c2.insert('c');   
    c2.insert('c');   
    c2.insert('a');   
    c2.insert('d');   
  
    c3.insert('c');   
    c3.insert('c');   
    c3.insert('a');   
    c3.insert('b');   
  
   cout << boolalpha;  
   cout << "c1 != c2: " << (c1 != c2) << endl;   
   cout << "c1 != c3: " << (c1 != c3) << endl;   
   cout << "c2 != c3: " << (c2 != c3) << endl;   
  
    return (0);   
}

Output:

c1 != c2: true

c1 != c3: false

c2 != c3: true

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

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

Parameters

left
An object of type unordered_multiset.

right
An object of type unordered_multiset.

Return Value

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

Remarks

The comparison between unordered_multiset objects is not affected by the arbitrary order in which they store their elements. Two unordered_multisets 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

C++
Copy 
// unordered_multiset_eq.cpp   
// compile by using: cl.exe /EHsc /nologo /W4 /MTd   
#include <unordered_set>   
#include <iostream>   
#include <ios>  
  
int main()   
{   
    using namespace std;  
  
    unordered_multiset<char> c1, c2, c3;  
  
    c1.insert('a');   
    c1.insert('b');   
    c1.insert('c');   
    c1.insert('c');   
  
    c2.insert('c');   
    c2.insert('c');   
    c2.insert('a');   
    c2.insert('d');   
  
    c3.insert('c');   
    c3.insert('c');   
    c3.insert('a');   
    c3.insert('b');   
  
   cout << boolalpha;  
   cout << "c1 == c2: " << (c1 == c2) << endl;   
   cout << "c1 == c3: " << (c1 == c3) << endl;   
   cout << "c2 == c3: " << (c2 == c3) << endl;   
  
    return (0);   
}

Output:

c1 == c2: false

c1 == c3: true

c2 == c3: false

<unordered_set>

Show: