I've got a need for regex and I would like to use it to extract tokens matching a regular expresssion from a file stream. Seems like this would be a common desire. So first shot is boost::regex_token_iterator<some_input_iterator> This doesn't work since regex_token_iterator requires a bidirectional iterator. Seems reasonable enough. So next I comb through boost and find #include <boost/spirit/iterator/multi_pass.hpp> and try boost::regex_token_iterator< boost::spirit::multi_pass<some_input_iterator>
I'm thinking this is veeeeeery cool - maybe a 1000 lines of free code included for the price of one. But, doesn't work. multi_pass is a forward_trasversal iterator while regex_token_iterator requires a bidirectional_trasversal_iterator. A huge disappoint to come soooo close. Thinking about it, this problem must come very often. How is it usually addressed? There must be a simple bridge across this. In a pinch, I'll just have to load the whole file into some sort collection, but I prefer the ultimate unlimited file size solution. Robert Ramey