set value_comp() function in C++ STL

The set::value_comp() is an inbuilt function in cpp that returns a copy of the comparison object used by the container. This object determines the order of the elements in the container. It is a function pointer or a function object that takes two arguments of the same type as the container elements, and returns true if the first argument is considered to go before the second in the strict weak ordering it defines, and false otherwise. Two elements of a set are considered equivalent if value_comp returns false reflexively (i.e., no matter the order in which the elements are passed as arguments).

Syntax:

value_compare set_name.value_comp() 

Parameters: This function does not accept any parameter.

Return value: The function returns a copy of the comparison object used by the container.

Below program illustrates the above function.

filter_none

edit
close

play_arrow

link
brightness_4
code

// CPP program to demonstrate the
// set::value_comp()
#include <bits/stdc++.h>
using namespace std;
  
int main()
{
    // initialising set a
    set<int> a;
  
    set<int>::value_compare comp = a.value_comp();
  
    // inserting elements to set a
    for (int i = 0; i <= 10; i++)
        a.insert(i);
  
    cout << "Set a has the numbers ";
  
    // start stores value of the last element of set a
    int start = *a.rbegin();
  
    // initialising iterator it
    set<int>::iterator it = a.begin();
  
    // Function that prints all the numbers in set
    do {
        std::cout << *it << " ";
    } while (comp(*(++it), start));
  
    std::cout << '\n';
  
    return 0;
}

chevron_right


Output:

Set a has the numbers 0 1 2 3 4 5 6 7 8 9


My Personal Notes arrow_drop_up

Contented with little yet wishing for more

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.




Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.