Pair (pair)

Definition

A struct pair is a heterogeneous pair of values. Its data members are first and second.

#include <pair>

Creation

pair<T1, T2> p ( T1 x, T2 y);
	Introduces a pair.

Operations

template <class T1, class T2>
bool	pair<T1,T2> p == pair<T1,T2> p1

Test for equality: Two pairs are equal, iff their data members are equal.

template <class T1, class T2>
bool	pair<T1,T2> p < pair<T1,T2> p1

Lexicographical comparison of two pairs.

Example

  Employee irene("Irene", "Eneri");
  Employee leo("Leonard", "Eneri");
  typedef int Social_security_number;

  pair<Social_security_number, Employee> p1(7812, irene),  p2(5555, leo);

  assert( p1.first == 7812 );
  assert( p2.second == leo );