On Tuesday, 24 November 2015 at 01:03:36 UTC, Steven
Schveighoffer wrote:
surely you mean opIndex? Note that ranges are required to
implement front, popFront, and empty. That's it, then it is a
range. Even save isn't required unless you want it to be a
forward range.
I meant .indexableRange, random access may require extra buffers
or stack space that take space even when random access isn't
used, and I'm asking for optional members(.retroRange,
.indexableRange)
But yes, a fundamental requirement is to be able to get the
front element repeatedly. This necessitates a buffer or "saving
of state".
Not quite what I was thinking. I was saying that ranges that
implement back,popBack may need to implement a backwards buffer
along a forward buffer even if the backwards buffer is never used.
