...documentation needs to clarify whether popFront may invalidate t, if t was obtained before via...

...currently, we *assume* that ranges will not invalidate the value of .front when popFront() is...

...front and then calling range.popFront() may _invalidate_ the copy. So basically, either you need...

...end of a range, it shouldn't invalidate the range at all. And that can...

...I don't see how that would invalidate the results. That is, I don't...

...change how some things work and possibly invalidate a feature which might seem reasonable now...

...that can invalidate a $(D DList) or $(D DList.Range), but
   which will invalidate BOTH...

...in that it _IS_ actually
possible to invalidate a DList itself (not just the range...

...meaning that operations "may or may mot" invalidate references. So it is not allowed to...

...memory a program may use, and hence invalidate the usability of an algorithm that depend...