[Speaking as one of the maintainers of the Iterator library only...] On Sat, Sep 29, 2012 at 9:29 AM, Louis Dionne <louis.dionne92@gmail.com>wrote:
Dear boost,
First of all, let me quickly introduce myself as this is my first post here: I am a 20 years old programming enthusiast with interest for metaprogramming, functional programming and library design. I also have a strong will to contribute to open source projects since I love the philosophy behind it and it is a great way to develop new skills and to work with talented people.
Welcome!
The object of this message is to collect feedback on several enhancement proposals I have prepared for two existing libraries:
[boost.iterator] [boost.iterator.accessor_iterator] The accessor_iterator is an iterator adaptor that returns a reference to a member of its pointee when dereferenced. I see it as another step in the direction of easier iterator composition, which has helped me writting less code in the past.
[boost.iterator.chained_output_iterator] The chained_output_iterator is an iterator adaptor allowing to apply a functional transformation to a value before outputing it into another output iterator. It is much like a function_output_iterator that would forward its result to another output iterator. It allows for cool stuff like creating a pipeline of operations without having to create temporary storage.
[...] Both of these sound like useful additions; I think it makes more sense to build these on top of transform_iterator and function_output_iterator directly in some fashion. In other words, I can see 3 ways of effecting the above (and I'm not sure which you've chosen, as I haven't looked at your code submission yet): create a new iterator independent of existing iterators; use iterator_adaptor to adapt an existing iterator; or provide a, e.g., a make_access_iterator function, which returns, e.g., a transform_iterator< mem_fn_t< PtrToMemFn >, BaseIterator > (so no actual new iterator types are provided, just convenience functions). I don't really see a point in doing the first, and the last should require the least amount of additional code. I'll take a glance at your code this weekend and likely have more targeted comments. All the code is available on github:
https://github.com/ldionne/boost-submissions
To see how each class can be used, you may look at the unit tests for the corresponding class.
If anything is accepted, I will be pleased to write documentation and examples for the concerned feature and to integrate it into the existing documentation.
Always a plus :) - Jeff