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Subject: Re: [boost] [Review:Algorithms] is_ordered name
From: Andrew Sutton (asutton.list_at_[hidden])
Date: 20110924 09:12:06
> With the RV convention change that I proposed on github (always point
> before the first element that is outoforder with respect to its
> predecessor, rather than the first that is outoforder with respect
> to its successor), it would be exactly the same, so I think we may be
> stuck with this name, even though I agree that it sounds like it
> should return a bool.
I'm not sure I understand the recommendation. Are you saying that if I write:
auto i = is_ordered(f, l, r)
Then I should have:
is_increasing(f, i);
Or, writing using std algorithms:
auto i = is_sorted_until(f, l, r)
assert(is_sorted(f, i));
> If we were starting from scratch my first impulse would be
> end_of_ordered_prefix(), but that too seems wordier than the ideal.
I think ordered_until is a reasonable name.
On a side note, I think the algorithm can be trivially implemented
using adjacent_find, and should have the same iterator requirements.
return adjacent_find(f, l, not2(pred));
Something like that.
On a technical note, an arbitrary predicate doesn't define an
ordering. You need a Pred to be a relation, a strict weak order. Also,
why not define the algorithm in terms of a natural order? Shouldn't I
be able to write is_ordered(f, l) if the iterator's value is totally
ordered?
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