Assign to element of DList

[cal]

The docs for std.container suggest I should be able to do this:

import std.container;

void main()
{
   auto list = DList!int([1,2,3,4,5]);
   list.front = 3;
}

But this does not compile (not a property list.front). I can't 
figure out why this doesn't work though - the source for struct 
DList(T) contains this:

static if(isAssignable!(T,T))
{
   @property void front(T value)
   {
     assert(!empty, "DList.front: List is empty");
     move(value, _first._payload);
   }
}

but that does not seem to be getting compiled in.