std::pair is class template to store two elements(special case of std::tuple)

according to cpp reference, the elements are accessible through first and second member objects.

there are several ways to create pair according to link. i am listing the 3 obvious ones here:

• default constructor if both types std;:is_default_constuctible_v for both types is true
• constructor (x,y) which initializes first and second to x and y
• copy contructor from another pain.

#include <iostream>
#include <utility>

using namespace std;

int main()
{
    std::pair<int, int> p;
    cout << p.first << " " << p.second << endl;
    std::pair<int, int> p1(1, 2);
    cout << p1.first << " " << p1.second << endl;

    auto p2 = make_pair(1, 1.1);
    cout << p2.first << " " << p2.second << endl;

}

make_pair Link to heading

pairs can be constructed using make_pair. which is template function to deduce the first and second types.

auto can be used with to make_pair to create pairs and `auto type deduction will figure it out.