vector< pair<pair<int, string> >, string> v;
Also mention how to access them using 'first' and second'. Is it even possible to do this or is "union" or "structure" the only way to create vector that can hold more than two data types?
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3Are you looking for a `std::pair` that holds three values? In that case see [std::tuple](http://en.cppreference.com/w/cpp/utility/tuple) – François Andrieux Jan 06 '17 at 18:12
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1having a pair, with a pair wihin it is no problem, but perhaps a [`std::tuple`](http://en.cppreference.com/w/cpp/utility/tuple) is more relevant here. – Tommy Andersen Jan 06 '17 at 18:12
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Is it possible to sort them if tuple is used? – theavatar Jan 06 '17 at 18:18
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@DeepakKumarG just as well as with a pair. In fact tuple is a generalization of `std::pair`. – Tommy Andersen Jan 06 '17 at 18:23
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2I would not use a `tuple` if you need to sort. In fact, a lot of things become more difficult when you switch to a tuple. Use a small struct for your triplet instead. – AndyG Jan 06 '17 at 18:32
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1BTW, you have a typo with misplaced `>`. – Jarod42 Jan 06 '17 at 18:34
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Thanks all,can someone tell how can it be done using std::vector and std::pair itself? – theavatar Jan 06 '17 at 18:38
1 Answers
4
std::vector< std::pair<std::pair<int, std::string>, std::string> > v; is possible, with
v[0].first.first = 42;
v[1].first.second = "hello";
v[2].second = "world";
std::tuple is a good alternative:
std::vector<std::tuple<int, std::string, std::string>> v = /*..*/;
std::get<0>(v[0]) = 42;
std::get<1>(v[0]) = "Hello";
std::get<2>(v[0]) = "World";
A proper structure allow to give semantic
struct Person
{
int age;
std::string firstName;
std::string lastName;
};
std::vector<Person> persons = /*...*/;
persons[0].age = 42;
persons[0].firstName = "John";
persons[0].lastName = "Doe";
Jarod42
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std::get<0>(v[0]) = 42; std::get<1>(v[0]) = "Hello"; std::get<2>(v[0]) = "World"; But Iam not able to assign values got from the input int n; cin>>n; get<0>(v[0])=n; Gives seg fault. – theavatar Jan 07 '17 at 05:22
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Thanks. You convinced me that going to a POD struct is better than messing around with tuples.... at least for my application. – rayryeng Jun 07 '18 at 19:09