C++ Pairs and Tuples

Pairs

pair<int, string> pr1; // declare

pr1 = {23, "helllo"}; // initialise or update
cout << pr1.first << " " << pr1.second << endl; // print

pr1 = {100, "Sarthak"};
pr1.second = "Sid";
cout << pr1.first << " " << pr1.second << endl;

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Tuples

tuple<DataType x1, DataType x2, ...DataType xN> tupleName

tuple<int, string, double> pl1 = {12, "hello", 56.10};
cout << get<0>(pl1) << get<1>(pl1) << get<2>(pl1) << endl;

// must initialise the variables of the same size of the tuple whose value are to be assigned to them
    // here tuple `tpl1` has 3 values so three variables of those respective "types" are declared
    int x;
    string str;
    double d;

    tie(x, str, d) = pl1;// giving values of tuple `tpl1` to the `s1`, `s2`, `s3`

    cout << x << str << d << endl;

tie()

• giving all tuple<> values to separate variables using tie()

// must initialise the variables of the same size of the tuple whose value are to be assigned to them
    // here tuple `tpl1` has 3 values so three strings are declared
    string s1;
    string s2;
    string s3;

    tie(s1, s2, s3) = tpl1; // giving values of tuple `tpl1` to the `s1`, `s2`, `s3`

• tie() can also be used to initialise tuple<> But Best way is to use tupleName = {..., .., ...} ⏩ tuple<int, string, double> pl1 = {12, "hello", 56.10};`

    tuple<int, int, int> t = tie(a, b, c);