public member type
<unordered_map>
key_equal key_eq() const;
Get key equivalence predicate
Returns the key equivalence comparison predicate used by the unordered_map container.
The key equivalence comparison is a predicate that takes two arguments of the key type and returns a bool value indicating whether they are to be considered equivalent. It is adopted by the container on construction (see unordered_map'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_map as an alias of its fourth template parameter (Pred).
Example
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// unordered_map::key_eq
#include <iostream>
#include <string>
#include <unordered_map>
int main ()
{
std::unordered_map<std::string,std::string> mymap;
bool case_insensitive = mymap.key_eq()("test","TEST");
std::cout << "mymap.key_eq() is ";
std::cout << ( case_insensitive ? "case insensitive" : "case sensitive" );
std::cout << std::endl;
return 0;
}
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Output:
mymap.key_eq() is case sensitive
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Iterator validity
No changes.