less verbose way to declare multidimensional std::array

c++, c++11, multidimensional-array

Solution

When nested, std::array can become very hard to read and unnecessarily verbose. The opposite ordering of the dimensions can be especially confusing.

For example:

std::array < std::array <int, 3 > , 5 > arr1; 

compared to

char c_arr [5][3]; 

Also, note that begin(), end() and size() all return meaningless values when you nest std::array.

For these reasons I've created my own fixed size multidimensional array containers, array_2d and array_3d. They have the advantage that they work with C++98.

They are analogous to std::array but for multidimensional arrays of 2 and 3 dimensions. They are safer and have no worse performance than built-in multidimensional arrays. I didn't include a container for multidimensional arrays with dimensions greater than 3 as they are uncommon. In C++11 a variadic template version could be made which supports an arbitrary number of dimensions (Something like Michael Price's example).

An example of the two-dimensional variant:

//Create an array 3 x 5 (Notice the extra pair of braces) 
fsma::array_2d <double, 3, 5> my2darr = {{ 
{ 32.19, 47.29, 31.99, 19.11, 11.19}, 
{ 11.29, 22.49, 33.47, 17.29, 5.01 }, 
{ 41.97, 22.09, 9.76, 22.55, 6.22 } 
}};  

Full documentation is available here: http://fsma.googlecode.com/files/fsma.html

You can download the library here: http://fsma.googlecode.com/files/fsma.zip

Problem

Original source