<unordered_set> operators
The latest version of this topic can be found at <unordered_set> operators.
| operator!= | operator== | operator!= (unordered_multiset) |
| operator== (unordered_multiset) |
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.
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
// 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
operator==
Tests whether the unordered_set object on the left side of the operator is equal to the unordered_set object on the right side.
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
// 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
operator!=
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.
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
// 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
operator==
Tests whether the unordered_multiset object on the left side of the operator is equal to the unordered_multiset object on the right side.
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
// 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