Re: [boost] Interest in updated, standalone iterator_facade library?

On Mon, Aug 12, 2019 at 5:45 PM Zach Laine via Boost wrote:

On Sun, Aug 11, 2019 at 10:22 AM Zach Laine wrote:

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On Sun, Aug 11, 2019 at 9:54 AM Francesco Guerrieri via Boost < boost@lists.boost.org> wrote:

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Do you think that the code is already useable, or is there something "big" left to do? I hope to give it a try in some days and of course will report back to you if there is anything relevant or useful.

I consider it to be ready, as-is. There may be bugs lurking that need to be fixed, but I don't know of any. I can write every kind of iterator I've ever needed to write (which is a lot). This includes all the iterator categories, plus proxy versions of each, and even weird stuff like back_insert_iterator.

Yeah, about this statement. I meant it yesterday when I made it. Then I started investigating what it would take to make something like a range_facade, as was suggested earlier in this thread. That lead me to discover std::view_interface, which I previously had never even heard of:

http://eel.is/c++draft/view.interface

It's pretty similar in concept to what iterator_facade does, but it does it using concept-based SFINAE on the members of std::view_interface, which leads to a small, easy-to-understand library interface, and a lot less library code. It also allows the user to specify operations with their usual spellings, like operator*() instead of dereference(). It also does not require the access type, because you don't have to make functions with odd names that you want to hide.

I like this a lot better. In fact, I like it so much better that I implemented something like it yesterday on a branch, renaming iterator_facade to iterator_interface:

It is a large change but it is for the better, I like it a lot. The "using operator++;" requirement is not too bad, it becomes mostly a matter of documentation. Thanks, Francesco