#include <iostream>
#include <vector>

#include <boost/spirit/include/phoenix.hpp>
#include <boost/spirit/include/qi.hpp>

namespace qi = boost::spirit::qi;
namespace px = boost::phoenix;

typedef std::string::const_iterator iterator_t;
typedef qi::rule<iterator_t, void(int&)> rule_t;

template<typename Expr>
inline bool parse_full(const std::string& input, const Expr& expr)
{
	iterator_t first(input.begin()), last(input.end());

	bool result = qi::phrase_parse(first, last, expr, boost::spirit::ascii::space);

	return first == input.end() && result;
}

void no_op() {}

int main(int argc, char *argv[]) 
{
	int attr = -1;

	// "Static" version - Works fine!
	/*
	rule_t grammar;
	
	rule_t ruleA = qi::char_('a')[qi::_r1 = px::val(0)];
	rule_t ruleB = qi::char_('b')[qi::_r1 = px::val(1)];
	rule_t ruleC = qi::char_('c')[qi::_r1 = px::val(2)];
	
	grammar = 
		ruleA(qi::_r1) | //[no_op]
		ruleB(qi::_r1) | //[no_op]
		ruleC(qi::_r1);  //[no_op]
	*/

	// "Dynamic" version - Does not compile! :(
	/*
	std::vector<rule_t> rules;

	rules.push_back(qi::char_('a')[qi::_r1 = px::val(0)]);
	rules.push_back(qi::char_('b')[qi::_r1 = px::val(1)]);
	rules.push_back(qi::char_('c')[qi::_r1 = px::val(2)]);

	std::vector<rule_t>::iterator i(rules.begin()), last(rules.end());
	
	rule_t grammar;

	grammar = (*i)(qi::_r1); //[no_op]

	for(++i; i!=last; ++i)
	{
		grammar = grammar.copy() | (*i)(qi::_r1); //[no_op]
	}
	*/

	// "Dynamic" version - Kind of works! :-/
	
	std::vector<rule_t> rules;

	rules.push_back(qi::char_('a')[qi::_r1 = px::val(0)]);
	rules.push_back(qi::char_('b')[qi::_r1 = px::val(1)]);
	rules.push_back(qi::char_('c')[qi::_r1 = px::val(2)]);

	std::vector<rule_t>::iterator i(rules.begin()), last(rules.end());
	
	qi::rule<iterator_t, int()> temp;

	temp = (*i)(qi::_val); //[no_op]

	for(++i; i!=last; ++i)
	{
		temp = temp.copy() | (*i)(qi::_val); //[no_op]
	}

	rule_t grammar;

	grammar = temp[qi::_r1 = qi::_1];

	// Tests

	if(parse_full("a", grammar(px::ref(attr)))) std::cout << attr << std::endl; // Should print: 0
	if(parse_full("b", grammar(px::ref(attr)))) std::cout << attr << std::endl; // Should print: 1
	if(parse_full("c", grammar(px::ref(attr)))) std::cout << attr << std::endl; // Should print: 2

	std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');

	return 0;
}