Andrei Alexandrescu wrote:
By the way, if anyone is interested in adding flex_string to boost :o), I have recently updated the code and reached a design and implementation I'm very happy with.
This is something that would be very useful, and something that would complement the fixed_string and const_string library proposals. However, there are a few limitations with the old version of flex_string (I am not sure about the new version - I am referring to the one used by wave). [1] The interface does not allow for "natural-style" string declerations (like you can do with iterator_facade). That is, you have: flex_string< char, const_string_impl< char > > my_str; or something similar, instead of the more ideal const_string< char > my_str; This is something I have tried to address with detail::basic_string_impl in my fixed_string library. [2] The class is *huge* :). I know that this is a side-effect of the complexity of the std::string interface, and my version (based on flex_string) suffers from this as well. One thing that I am looking into - but there are a lot of issues with - is trying to split up the design into usable, flexible components. That is, you could do: class my_container: public sequence::reverse_iterator< my_container > { // defines [const_]iterator, begin() and end() }; and sequence::reverse_iterator will add [const_]reverse_iterator, rbegin() and rend() defined in terms of the others. The idea is to break up the string interface into its standard modules (capacity, iterators, etc.), with the flex_string-style class pulling in all of these. This allows a more flexible implementation and can be used by containers to implement the iterator component. This could be extended to support common implementations for container methods (e.g. back()/front() in terms of begin() and end()). The idea behind this is for the classes as a whole to behave like iterator_facade. Regards, Reece Reece Haston Dunn Software Engineer, Sophos Web: www.sophos.com Sophos - protecting businesses against viruses and spam