Hello Eric, sorry for bothering. I use xpressive in the following context: typedef x::sregex regex_type; const regex_type non_semicolon = ~x::as_xpr(';'); const regex_type sem_separated = *non_semicolon; typedef boost::iterator_range<x::sregex_token_iterator> regex_tokens; typedef ::std::vector<regex_tokens> regex_transformed_collection; inline regex_tokens apply_regex(regex_type const& re, std::string const& item) { typedef x::sregex_token_iterator sre_iter; return boost::make_iterator_range(sre_iter(item.begin(), item.end(), re), sre_iter()); } // usage: std::vector<std::string> v; //vector is filled with strings of type: some_part;some_other_part typedef regex_transformed_coll::const_iterator re_citer; regex_transformed_collection sep_strings; ::std::transform ( v.begin(), v.end(), ::std::back_inserter(sep_strings) , ::std::tr1::bind(&apply_regex, sem_separated, tr1::placeholders::_1) ); //v is in the same scope and valid for(re_citer curr=sep_strings.begin(), end=sep_strings.end(); curr!=end; ++curr) { regex_tokens const& toks = *curr; std::string source = toks.front(); //this line is fine and returns me the first part of a string... // all subsequent line will raise an assertion std::string includes = *++toks.begin(); size_t sz = toks.size(); } Is there smth. I did not take in account? This code crashes in: regex_token_iterator.hpp: regex_token_iterator<BidiIter> &operator ++() { ->>HERE>> this->fork_(); // un-share the implementation And is caused by regex_token_iterator_impl ctor. I know this code is not very efficient, since it iterates through the collection of strings twice instead of doing smth. within one run, but it is just an example. Many thanks, Ovanes
Ovanes Markarian wrote:
Hello Eric,
sorry for bothering. I use xpressive in the following context:
<snip> I can't get your code to compile. Please send a minimal and complete source file that demonstrates the problem. Note: I'm currently in New York for my sister's wedding. I may not get to this until next week. -- Eric Niebler Boost Consulting www.boost-consulting.com
Eric Niebler wrote:
Ovanes Markarian wrote:
Hello Eric,
sorry for bothering. I use xpressive in the following context:
<snip>
I can't get your code to compile. Please send a minimal and complete source file that demonstrates the problem.
After fiddling with your code a bit, I got it to compile, but I'm not seeing any assertions, exceptions or crashes. What version are you using? Below is the full source. I had to comment out the line to toks.size() -- iterator_range::size() requires random access iterators, and regex_token_iterator is not random access. I can't imagine how this compiles for you. Also, your example is highly suspect at this line: std::string includes = *++toks.begin(); iterator_range::begin() returns an iterator *by value*. The ++ is mutating the copy, not the iterator stored in the range. Did you mean to do that? #include <string> #include <iostream> #include <boost/tr1/functional.hpp> #include <boost/range/iterator_range.hpp> #include <boost/xpressive/xpressive.hpp> namespace x = boost::xpressive; typedef x::sregex regex_type; const regex_type non_semicolon = ~x::as_xpr(';'); const regex_type sem_separated = *non_semicolon; typedef boost::iterator_range<x::sregex_token_iterator> regex_tokens; typedef ::std::vector<regex_tokens> regex_transformed_collection; inline regex_tokens apply_regex(regex_type const& re, std::string const& item) { typedef x::sregex_token_iterator sre_iter; return boost::make_iterator_range(sre_iter(item.begin(), item.end(), re), sre_iter()); } // usage: int main() { std::vector<std::string> v; //vector is filled with strings of type: some_part;some_other_part typedef regex_transformed_collection::const_iterator re_citer; regex_transformed_collection sep_strings; ::std::transform ( v.begin(), v.end(), ::std::back_inserter(sep_strings) , ::std::tr1::bind(&apply_regex, sem_separated, std::tr1::placeholders::_1) ); //v is in the same scope and valid for(re_citer curr=sep_strings.begin(), end=sep_strings.end(); curr!=end; ++curr) { regex_tokens const& toks = *curr; std::string source = toks.front (); //this line is fine and returns me the first part of a string... // all subsequent line will raise an assertion std::string includes = *++toks.begin(); //size_t sz = toks.size(); } return 0; } -- Eric Niebler Boost Consulting www.boost-consulting.com
Eric Niebler wrote:
Eric Niebler wrote:
Ovanes Markarian wrote:
Hello Eric,
sorry for bothering. I use xpressive in the following context: <snip>
I can't get your code to compile. Please send a minimal and complete source file that demonstrates the problem.
After fiddling with your code a bit, I got it to compile, but I'm not seeing any assertions, exceptions or crashes. What version are you using?
Me again. I realized I wasn't seeing the problem because I hadn't put any strings in the vector over which you were iterating. When I do, I can reproduce the assert. This is not a bug in xpressive, it is a bug in your code. The problem is here: std::tr1::bind(&apply_regex, sem_separated, td::tr1::placeholders::_1) In this call to bind, you pass sem_separated to bind() *by value*. You return a regex_token_iterator, which holds a reference to the (temporary) regex object. When the temporary regex object goes away, the regex_token_iterators are left holding dangling references. The lifetime of a regex_token_iterator cannot exceed the lifetime of the regex it holds. If you change the code to ... std::tr1::bind(&apply_regex, std::tr1::ref(sem_separated), td::tr1::placeholders::_1) ... it works just fine. HTH, -- Eric Niebler Boost Consulting www.boost-consulting.com
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Ovanes Markarian