...and just skip destroying any that would invalidate the source.

Thus, I propose we formally...

...any garbage in higher bits doesn't invalidate the bool.
But of course, even values...

...we need to be able to (say) invalidate an immutable range when it's data...

...heap compaction in D, because this would invalidate pointers. Most high performance GCs use heap...

...argument to your example (which doesn't invalidate yout point).

The pessimisation for short lines...

...by reference, if changes to the AA invalidate the type returned by front, etc.

In...

...you referring to ranges like `byLine` that invalidate the previous front when popFront is called...

...Copying it and iterating the copy will invalidate the original. Yet it is perfectly capable...

...guaranteed to remain
   valid, or does .popFront invalidate it?  This is not specified in the...

...to do with the range) won't invalidate the cursor.

What I wanted was the...