Hi,
2. Make the filter_type public or templated (with boost::function as default). Simply because I'd like to avoid dynamic memory allocation when in functions creating those iterators. It feels a bit unnecessary and I can't create something of filter_iterator_base::finder_type, since it's protected.
I'm not really sure what you are trying to achieve. boost::function is used to to handle the type erasure. As far as I know, it is not possible to do this without some dynamic allocation and virtualization. Without the type erasure, the find_iterators would have to be templated by the finder type.
That was what I was thinking. They could be templated there, but using boost::function as a default template arg. This would provide type erasure by default, but allow higher performance where needed. Since it's already templated on one type, it might as well be on one more, or?
Without the type erasure, the usage of iterators would get less convenient. For example, you would not be able to compare iterators with different finders. This is manifested when using default constructed find iterator as end-of-search tag. Anyway, maybe the default template argument is a way to go. I will think about it.
It's a minor thing though. Sorry for the noise.
No problem. Every suggestion is worth consideration. Regards, Pavol.