variable x cannot be read at compile time - how to get around this?

[Sergey via Digitalmars-d]

  Hello everyone!

I need to create a two-dimensional array in this way, for example:
auto x = 10;
auto y = 10;
auto some_array = new string[x][y];
variable x cannot be read at compile time

I tried this:
enum columns_array = 
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20];
auto y = 10;
int i = 1;
auto some_array = new string[columns_array[i]][y];
Error: columns_array is used as a type

And yet, if I have a function:
string[x][] some_function (some par) {
   auto x = 10;
   auto y = 10;
   auto some_array = new string[x][y];
   return some_array;
   }

Thanks in advance.