rotate left an array

[Fausto via Digitalmars-d-learn]

Hello all,

I am trying to rotate left an array.
I found a very basic way, and I am not sure if there is something 
clever than this :) maybe using slices...
the external for represents how many times you are rotating (in 
this case 2).

```d
void main()
{
    import std.range;
    import std.stdio: write, writeln, writef, writefln;

    int[] arr1 = [ 1, 2, 3, 4 ];
    int t = 0;

    writeln(arr1);

    for (int j = 0;j<2;j++) {
    t = arr1[0];
    for(int i = 0;i<arr1.length-1;i++) {
        arr1[i] =  arr1[i+1];
    }
    arr1[$-1] = t;
    }

    writeln(arr1);

}
```

thanks a lot
Fausto