Scroll to navigation

std::make_pair(3) C++ Standard Libary std::make_pair(3)

NAME

std::make_pair - std::make_pair

Synopsis


Defined in header <utility>
template< class T1, class T2 > (until C++11)
std::pair<T1,T2> make_pair( T1 t, T2 u );
template< class T1, class T2 > (since C++11)
std::pair<V1,V2> make_pair( T1&& t, T2&& u ); (until C++14)
template< class T1, class T2 > (since C++14)
constexpr std::pair<V1,V2> make_pair( T1&& t, T2&& u );


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


The deduced types V1 and V2 are std::decay<T1>::type and
std::decay<T2>::type (the usual type transformations applied to
arguments of functions passed by value) unless application of (since C++11)
std::decay results in std::reference_wrapper<X> for some type X, in
which case the deduced type is X&.

Parameters


t, u - the values to construct the pair from

Return value


A std::pair object containing the given values.

Example

// Run this code


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


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)

2022.07.31 http://cppreference.com