operator== (<utility>)

Tests if the pair object on the left side of the operator is equal to the pair object on the right side.

template<class Type1, class Type2> 
   bool operator==( 
      const pair<Type1, Type2>& _Left, 
      const pair<Type1, Type2>& _Right 
);

Parameters

• _Left
  An object of type pair.

• _Right
  An object of type pair.

Return Value

true if the pairs are equal; false if the pairs are not equal.

Remarks

One pair is equal to another pair if each of their respective elements is equal. The function returns _Left.first == _Right.first && _Left.second == _Right.second. Two pairs are unequal if either the first or the second element of one is not equal to the corresponding element of the other pair.

Example

// utility_op_eq.cpp
// compile with: /EHsc
#include <utility>
#include <iomanip>
#include <iostream>

int main( )
{
   using namespace std;
   pair <int, double> p1, p2, p3;

   p1 = make_pair ( 10, 1.11e-1 );
   p2 = make_pair ( 1000, 1.11e-3 );
   p3 = make_pair ( 10, 1.11e-1 );

   cout.precision ( 3 );
   cout << "The pair p1 is: ( " << p1.first << ", " 
        << p1.second << " )." << endl;
   cout << "The pair p2 is: ( " << p2.first << ", " 
        << p2.second << " )." << endl;
   cout << "The pair p3 is: ( " << p3.first << ", " 
        << p3.second << " )." << endl << endl;

   if ( p1 == p2 )
      cout << "The pairs p1 and p2 are equal." << endl;
   else
      cout << "The pairs p1 and p2 are not equal." << endl;

   if ( p1 == p3 )
      cout << "The pairs p1 and p3 are equal." << endl;
   else
      cout << "The pairs p1 and p3 are not equal." << endl;
}

Output

The pair p1 is: ( 10, 0.111 ).
The pair p2 is: ( 1000, 0.00111 ).
The pair p3 is: ( 10, 0.111 ).

The pairs p1 and p2 are not equal.
The pairs p1 and p3 are equal.

Requirements

Header: <utility>

Namespace: std