public member type
<unordered_set>
key_equal key_eq() const;
Get key equivalence predicate
Returns the key equivalence comparison predicate used by the unordered_multiset container.
The key equivalence comparison is a predicate that takes the value of two elements as arguments and returns a bool value indicating whether they are to be considered equivalent. It is adopted by the container on construction (see unordered_multiset's constructor for more info). By default, it is equal_to<key_type>, which returns the same as applying the equal-to operator (==) to the arguments.
Return Value
The key equality comparison object.
Member type key_equal is the type of the key equality comparison predicate used by the container, defined in unordered_multiset as an alias of its third template parameter (Pred).
Example
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
// unordered_multiset::key_eq
#include <iostream>
#include <string>
#include <unordered_set>
int main ()
{
std::unordered_multiset<std::string> myums;
bool case_insensitive = myums.key_eq()("case","CASE");
std::cout << "myums.key_eq() is ";
std::cout << ( case_insensitive ? "case insensitive" : "case sensitive" );
std::cout << std::endl;
return 0;
}
| |
Output:
myums.key_eq() is case sensitive
|
Iterator validity
No changes.