Re: [boost] [range] RFC: span(iterator, size)

2013/10/30 TONGARI J

2013/10/30 Akira Takahashi ...

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What do you think about out of range check?

I'd say, it's the user's duty to ensure it won't go over the end.

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What situation is it useful?

When you want to ignore the difference between RandomAccessIterator & ForwardIterator while keeping the efficiency of RandomAccessIterator.

Some API may look like this: function(iterator, n, ...) that only require iterator to be ForwardIterator, but the implementation may sacrifice the efficiency of RandomAccessIterator, just because the implementor doesn't want to bother tag-dispatching for such optimization... (OK, I'm the one)

Thank you. I understood your motivation. My opinion is here: First, I wouldn't like to provide iterator interface in Boost.Range functions (expect begin/end). In my opinion, iterator is low layer interface. It is not Boost.Range layer. Second, I rethink interface by first reason: r | random_access_taken(n); or r | random_access_span(n); I don't think useful the function (explicit efficient phrase). At least, we need better name for random access. However, my `taken` implementation hasn't optimization for random access iterator. I'll add optimization to `taken` implementation. Thanks, Akira