C++ Functional Library - equal_to

Description

It is a function object class for equality comparison and binary function object class whose call returns whether its two arguments compare equal (as returned by operator ==).

Declaration

Following is the declaration for std::equal_to.

template <class T> struct equal_to;

C++11

template <class T> struct equal_to;

Parameters

T − It is a type of the arguments and return type of the functional call.

Return Value

none

Exceptions

noexcep − It doesn't throw any exceptions.

Example

In below example explains about std::equal_to.

#include <iostream>     
#include <utility>      
#include <functional>   
#include <algorithm>    

int main () {
   std::pair<int*,int*> ptiter;
   int foo[]={10,20,30,40};
   int bar[]={10,50,40,80};
   ptiter = std::mismatch (foo, foo+5, bar, std::equal_to<int>());
   std::cout << "First mismatching pair is: " << *ptiter.first;
   std::cout << " and " << *ptiter.second << '\n';
   return 0;
}

Let us compile and run the above program, this will produce the following result −

First mismatching pair is: 20 and 50