Hello,
     This is my first time using boost and spirit. I am trying to find construct a tree from a string input. While parsing I am trying to assign each created node a number. For this purpose I am using a inherited attribute, an integer reference. But when I check on the values assigned. It is not the value of the integer reference rather some other value (some consistent value). I am sure this must be something that I am overlooking. But I am not sure what exactly.

Thanks for your help,
Anand Kumar.

Code:

struct node;

struct term {
bool visited;
int cnt;
int val;

term(bool b = false, int cn = -1, int v = numeric_limits<int>::min())
{
    visited = b;
    cnt = cn;
    val = v;
}
};

BOOST_FUSION_ADAPT_STRUCT(
            ::term,
            (bool, visited)
            (int, cnt)
            (int, val)
            )

typedef boost::variant<term, boost::recursive_wrapper<node>> node_impl;

struct node {
bool visited;
int cnt;
vector<node_impl> children;
};

BOOST_FUSION_ADAPT_STRUCT(
            ::node,
            (bool, visited)
            (int, cnt)
            (std::vector<::node_impl>, children)
            )

template<typename Iterator>
struct node_parser : qi::grammar<Iterator, node(), ascii::space_type> {

qi::rule<Iterator, node(), ascii::space_type> start_r;
qi::rule<Iterator, node(int&), ascii::space_type> node_r;
qi::rule<Iterator, node_impl(int&), ascii::space_type> node_impl_r;

node_parser() : node_parser::base_type(start_r)
{
    using qi::int_;
    using qi::lexeme;
    using namespace qi::labels;
    using phoenix::ref;
    int cnt = 990;

    start_r %= node_r(phoenix::ref(cnt));
    node_r = ('{' >> +node_impl_r(_r1) >> '}') [at_c<0>(_val) = false, at_c<1>(_val) = _r1++, at_c<2>(_val) = _1];
    node_impl_r = ((lexeme['(' >> int_ >> ')'])[_val = phoenix::construct<term>(phoenix::val(false), _r1++, _1)]) | (node_r(_r1)[_val = _1]);
}
};