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digitalmars.D.learn - How do I check if a variable is a multidimensional (2D) array?

reply Kirill <kirill.saidov mail.com> writes:
I know there is isArray!T and similar functionality in 
std.traits. But I couldn't find the functionality that can help 
me check if I have a multidimensional array. Is there any? How do 
I create my own?

Thanks in advance.
Jul 11 2021
parent reply jfondren <julian.fondren gmail.com> writes:
On Monday, 12 July 2021 at 04:25:00 UTC, Kirill wrote:

 I know there is isArray!T and similar functionality in 
 std.traits. But I couldn't find the functionality that can help 
 me check if I have a multidimensional array. Is there any? How 
 do I create my own?

 Thanks in advance.


from https://github.com/PhilippeSigaud/D-templates-tutorial

```d
template rank(T) {
     static if (is(T t == U[], U))
         enum size_t rank = 1 + rank!(U);
     else
         enum size_t rank = 0;
}

unittest {
     int a;
     int[] b;
     int[][] c;
     assert(rank!(typeof(a)) == 0);
     assert(rank!(typeof(b)) == 1);
     assert(rank!(typeof(c)) == 2);
}
```

as an example of a recursive template. There's also an 
implementation for ranges.
Jul 11 2021
parent Kirill <kirill.saidov mail.com> writes:
On Monday, 12 July 2021 at 05:08:29 UTC, jfondren wrote:

 On Monday, 12 July 2021 at 04:25:00 UTC, Kirill wrote:

 I know there is isArray!T and similar functionality in 
 std.traits. But I couldn't find the functionality that can 
 help me check if I have a multidimensional array. Is there 
 any? How do I create my own?

 Thanks in advance.


 from https://github.com/PhilippeSigaud/D-templates-tutorial

 ```d
 template rank(T) {
     static if (is(T t == U[], U))
         enum size_t rank = 1 + rank!(U);
     else
         enum size_t rank = 0;
 }

 unittest {
     int a;
     int[] b;
     int[][] c;
     assert(rank!(typeof(a)) == 0);
     assert(rank!(typeof(b)) == 1);
     assert(rank!(typeof(c)) == 2);
 }
 ```

 as an example of a recursive template. There's also an 
 implementation for ranges.


Thanks!
Jul 11 2021