C++ Set Library - key_comp Function

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Description

It returns a copy of the comparison object used by the container.

Declaration

Following are the ways in which std::set::key_comp works in various C++ versions.

C++98

key_compare key_comp() const;

C++11

key_compare key_comp() const;

Return value

It returns a copy of the comparison object used by the container.

Exceptions

If an exception is thrown, there are no changes in the container.

Time complexity

Time complexity depens on logarithmic.

Example

The following example shows the usage of std::set::key_comp.

#include <iostream>
#include <set>

int main () {
   std::set<int> myset;
   int highest;

   std::set<int>::key_compare mycomp = myset.key_comp();

   for (int i = 0; i <= 10; i++) myset.insert(i);

   std::cout << "myset contains:";

   highest=*myset.rbegin();
   std::set<int>::iterator it = myset.begin();
   do {
      std::cout << ' ' << *it;
   } while ( mycomp(*(++it), highest) );

   std::cout << '\n';

   return 0;
}

The above program will compile and execute properly.

myset contains: 0 1 2 3 4 5 6 7 8 9