Storing a boost::spirit::qi::rule in a std::list

Question

I have read the other thread about copy or reference semantics for boost::spirt::qi::rule. I am using Boost 1.42.

using boost::spirit::qi::phrase_parse;
typedef boost::spirit::qi::rule < std::string::const_iterator, boost::spirit::ascii::space_type > rule_type;
std::list < rule_type > ruleList;
std::string const s("abcdef");
std::string::const_iterator iter = s.begin(), end = s.end();
std::cout << typeid(char_).name() << std::endl;
ruleList.push_back(char_);
ruleList.push_back(*ruleList.back());
assert(phrase_parse(iter, s.end(), ruleList.back(), boost::spirit::ascii::space));
assert(iter == s.end());

This fails with...

Assertion `phrase_parse(iter, s.end(), ruleList.back(), traits::space())' failed.
Aborted (core dumped)

Is there a way to store rules in a STL list or deque? (References don't die until removed).

Answer 1

With Boost V1.45, this (essentially your code from above) works without problems (MSVC2010, g++ 4.5.1):

#include <list>
#include <string>
#include <iostream>
#include <boost/spirit/include/qi.hpp>

using namespace boost::spirit; 

int main()
{
    typedef qi::rule<std::string::const_iterator, ascii::space_type> rule_type; 
    std::list<rule_type> ruleList; 

    std::string const s("abcdef"); 
    std::string::const_iterator iter = s.begin(), end = s.end(); 
    std::cout << typeid(qi::char_).name() << std::endl; 

    ruleList.push_back(qi::char_); 
    ruleList.push_back(*ruleList.back()); 

    assert(qi::phrase_parse(iter, s.end(), ruleList.back(), ascii::space)); 
    assert(iter == s.end());

    return 0;
}

Therefore, I assume it's a bug in the version of Spirit you're using.

Answer 2

I could not get your example to compile. Aside from not using the correct types from ...::qi, you added a () to the trait::space type.

This works w/o problem for me (boost 1.44)

#include <boost/spirit/include/qi.hpp>
#include <string>
#include <vector>
#include <cassert>

using boost::spirit::qi::phrase_parse;

typedef boost::spirit::qi::rule < std::string::const_iterator, boost::spirit::qi::space_type > rule_type;

int main() {

std::list < rule_type > ruleList;
std::string const s("abcdef");
std::string::const_iterator iter = s.begin(), end = s.end();
ruleList.push_back(*boost::spirit::qi::char_);
assert(phrase_parse(iter, s.end(), ruleList.back(), boost::spirit::qi::space));
assert(iter == s.end());

}

~>g++ test.cpp && ./a.out
~>

please note I use qi::space_type and `qi::space instead of the ascii namespace. I have no idea what/where the trait namespace is.