static foreach over constant range in @nogc block

[tspike]

I came across an issue recently that I’m a little confused by. 
The following program fails to compile under LDC and DMD, though 
it compiles fine under GDC:

     @nogc:

     void main()
     {
         static foreach(i; 0 .. 4)
         {
             pragma(msg, i);
         }
     }

Both DMD and LDC report the following error if I try to compile 
it:

     test.d(7): Error: cannot use operator ~= in @nogc delegate 
test.main.__lambda1

I was just wondering, is this is a compiler bug or is there a 
reason I'm overlooking preventing this sort of code from 
compiling?