Traverse a DList and insert / remove in place?

[Armando]

ok there is the issue of not knowing how to traverse the list 
after removing the current element (=> the one that came after of 
course). But how about even just keeping a pointer (range) to 
'element' that can be used after the list has been traversed in 
full to use in remove / insertAfter?

I think I can achieve this with associative arrays (below) but it 
seems overkill to use an associative effectively as a DList?

```d
struct myType{
     int id;
     int prev, next; // id of prev and next
     // [...] other stuff

     this(int id_, int prev_, int next_)
     {
         //[...]
     }
}

myType[int] list; // key = id

int[] to_remove;
myType[] to_add;

foreach(elem; list)
{
     // [...] do something long and complicated with elem, throw a 
random number rand

     if(rand < 0.5)
         to_remove ~= elem.id; // flag for removal
     else
         to_add ~= myType(some_new_id, elem.id, elem.next); // add 
new elem after current
}

foreach(elem; to_add)
     list[elem.id] = elem;

foreach(id; to_remove)
{
     // reconnect: prev's next to next, and next's prev to prev
     list[list[id].prev].next = list[id].next;
     list[list[id].next].prev = list[id].prev;
     list.remove(id);
}

```