std::array member functions

[technologist]

In my code below, can I use .member functions for std::array?

#include<iostream>
#include <array>

using namespace std;

void print_array(std::array<int,52> & deck)
{}; //hold for now...works

int main()
{
	std::array<int, 52> deck;

	int card = 0;
	for (int suit = 0; suit < 5; ++suit) //numbers wrong, prototyping
	for (int rank = 0; rank < 5; ++rank)
	{
	deck[card].rank = rank;
		//deck[card].rank = static_cast<CardRank>(rank);
		++card;
	}

	return 0;
}

error reported:
..\src\main.cpp:17:13: error: request for member 'rank' in 'deck.std::array<_Tp, _Nm>::operator[]<int, 52ull>(((std::array<int, 52ull>::size_type)card))', which is of non-class type 'std::array<int, 52ull>::value_type {aka int}'

[cire]

In my code below, can I use .member functions for std::array?

Certainly. But the elements of the array-of-int you have here don't have a rank member.

[technologist]

How do I assign a rank member to array-of-ints elements? Just learning std::array.

[cire]

You don't.

If you want an array of elements that have a 'rank' member, you must define that type first. Then, you may make an array of elements of that type.

[technologist]

you must define that type first. Then, you may make an array of elements of that type.

Hate to ask this, but can you please post an example snippet? If u have time.

[TwilightSpectre]

I assume something like this:

struct Card {
    int rank;
    // ...
};

// ...

std::array<Card, 52> deck;
deck[0].rank = 0;

[technologist]

Seeing both the "old way" and the c++11 std::array in one context helped me understand this better. Both take objects of a certain type and members. I was used to using an array of structs before c++11...and then it was lost on me with std::array--> but its a lot clearer now.

#include<iostream>
#include<array>

using namespace std;

struct Card {
    int rank;
};

int main()
{

std::array<Card, 52> deck;
deck[0].rank = 99;
cout<<deck[0].rank<<endl;

//older way

Card * n_ptr = new Card();
n_ptr->rank = 1020;
cout<<n_ptr->rank;
return 0;

}

[coder777]

Note that the members of Card/deck remain uninitialized unless you provide a constructor.

[technologist]

Do I provide that constructor by initializing the object Card card?

[TarikNeaj]

Study classes so you'll get a good grip on all of this stuff - http://www.cplusplus.com/doc/tutorial/classes/

[technologist]

Thx