My data is structured like this:
[Unique ID1] Variable Name = Variable Value Variable Name = Variable Value Variable Name = Variable Value
[Unique ID2] Variable Name = Variable Value Variable Name = Variable Value Variable Name = Variable Value Variable Name = Variable Value
All I need to do is to extract the different parts, to be saved in a map. In my first callback, I divide every section into (a) Unique ID, and (b) rest of the (multiline) block. Once I have the latter, I make a call to a second callback to break the LHS and the RHS of each assignment expression.
So you say that the callback is really not required?
How about nested for-loops (caution untested code!!): std::string text = get_text_from_file(); regex block_extractor("\\[(\\w+)\\]([^\\[]+)"); regex variable_extractor("(\\w+)\\s*=\\s*(\\w+)"); for(regex_iterator<std::string::const_iterator> i = make_regex_iterator(text, block_extractor); i != regex_iterator<std::string::const_iterator>(); ++i) { std::string block_name = i->str(1); std::string block_contents = i->str(2); std::map<std::string, std::string> param_list; for(regex_iterator<std::string::const_iterator> j = make_regex_iterator(block_contents, variable_extractor); j != regex_iterator<std::string::const_iterator>(); ++j) { param_list[j->str(1)] = j->str(2); } } Obviously the regexes used may vary depending upon the exact data format, but hopefully this should give you the general idea? John.