声明多维std :: arrays

Question

This is the first time that I am going to use a multidimensional std::array. I want to declare 9 matrix of 3 x 3 dimensions.

In a conventional c++ array we declare like the following.

int a[9][3][3];

When I try to declare this array using std::array the sequence of dimensions is upside down, It must be declared like the following.

array<array<array<int, 3>, 3, 9)

my expectation was to declare that matrix like we declare the conventional arrays like the following.

  array<array<array<int, 9>, 3, 3)

There is no documentation on this matter. What is the C++ standard

Answer 1

Use > instead of ) :

using matrices = array<array<array<int,3>,3>,9>;

And you can write, as suggested in the comments:

// N is number of rows, M number of columns
template<int N, int M>
using matrix = array<array<int,N>,M>;

using matrices = array<matrix<3,3>,9>;

Answer 2

Check out Why can't simple initialize (with braces) 2D std::array?

Try std::array<std::array<std::array<int, 3>, 3>, 9> myArray; .

Remember to #include<array> .