std:: make_pair

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C++
Utilities library
General utilities
Relational operators (deprecated in C++20)
std::pair
Defined in header <utility>
template < class T1, class T2 >
std:: pair < T1, T2 > make_pair ( T1 x, T2 y ) ;
(until C++11)
template < class T1, class T2 >
std:: pair < /*V1*/ , /*V2*/ > make_pair ( T1 && x, T2 && y ) ;
(since C++11)
(constexpr since C++14)
(until C++20)
template < class T1, class T2 >

constexpr std:: pair < std:: unwrap_ref_decay_t < T1 > ,
std:: unwrap_ref_decay_t < T2 >>

make_pair ( T1 && x, T2 && y ) ;
(since C++20)

Creates a std::pair object, deducing the target type from the types of arguments.

Given types std:: decay < T1 > :: type as U1 and std:: decay < T2 > :: type as U2 , the types /*V1*/ and /*V2*/ are defined as follows:

(since C++11)
(until C++20)

Parameters

x, y - the values to construct the pair from

Return value

std:: pair < T1, T2 > ( x, y )

(until C++11)

std:: pair < /*V1*/ , /*V2*/ > ( std:: forward < T1 > ( x ) , std:: forward < T2 > ( y ) )

(since C++11)
(until C++20)

std:: pair < std:: unwrap_ref_decay_t < T1 > , std:: unwrap_ref_decay_t < T2 >>
( std:: forward < T1 > ( x ) , std:: forward < T2 > ( y ) )

(since C++20)

Example

Run this code 
#include <functional>
#include <iostream>
#include <utility>
 
int main()
{
    int n = 1;
    int a[5] = {1, 2, 3, 4, 5};
 
    // build a pair from two ints
    auto p1 = std::make_pair(n, a[1]);
    std::cout << "The value of p1 is "
              << '(' << p1.first << ", " << p1.second << ")\n";
 
    // build a pair from a reference to int and an array (decayed to pointer)
    auto p2 = std::make_pair(std::ref(n), a);
    n = 7;
    std::cout << "The value of p2 is "
              << '(' << p2.first << ", " << *(p2.second + 2) << ")\n";
}

Output: 

The value of p1 is (1, 2)
The value of p2 is (7, 3)

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 181 C++98 the parameter types were const-reference
types, which made passing arrays impossible 		changed these
types to value types
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