BitArray in custom class & initialize it in ctor with arguments

[MarisaLovesUsAll]

Hi! I need to use array of bits in my custom class. I tried to
add std.bitmanip.BitArray as field, but got a strange error. What
am I doing wrong?

import std.bitmanip;
class Scene
{
      BitArray collisionMap;
      this(int w, int h)
      {
          collisionMap.init([0,0,0]);
      }
}

C:\D\dmd2\windows\bin\..\..\src\phobos\std\bitmanip.d
line 606
Error: btr cannot be interpreted at compile time, because it has
no available source code


If I use collisionMap.length(w*h), I get:

C:\D\dmd2\windows\bin\..\..\src\phobos\std\bitmanip.d
line 554
Error: non-constant expression [0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u,
0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u,
0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u,
0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u,
0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u,
0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u,
0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u,
0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u,


And if I use BitArray in default ctor ( this() ), or in other
function in class, or in main function, all is OK. But I need
only ctor with arguments that initialize the BitArray with '0'
and sets 'w*h' length.

DMD version 2.065.0

Sorry for bad English.