不能编译boost spirit example4.cpp

我正在继续学习Boost Spirit库，我有一些问题的例子，我无法编译。您可以在这里找到示例的源代码:源位置。您还可以查看此代码并在Coliru上编译结果。

#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/lex_lexertl.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
#include <iostream>
#include <fstream>
#include <string>
using namespace boost::spirit;
using boost::phoenix::val;
///////////////////////////////////////////////////////////////////////////////
//  Token definition
///////////////////////////////////////////////////////////////////////////////
template <typename Lexer>
struct example4_tokens : lex::lexer<Lexer>
{
    example4_tokens()
    {
        identifier = "[a-zA-Z_][a-zA-Z0-9_]*";
        constant = "[0-9]+";
        if_ = "if";
        else_ = "else";
        while_ = "while";
        this->self = lex::token_def<>('(') | ')' | '{' | '}' | '=' | ';' | constant;
        this->self += if_ | else_ | while_ | identifier;
        this->self("WS")
            =   lex::token_def<>("[ \t\n]+") 
            |   "\/\*[^*]*\*+([^/*][^*]*\*+)*\/"
            ;
    }
    lex::token_def<> if_, else_, while_;
    lex::token_def<std::string> identifier;
    lex::token_def<unsigned int> constant;
//]
};
template <typename Iterator, typename Lexer>
struct example4_grammar 
  : qi::grammar<Iterator, qi::in_state_skipper<Lexer> >
{
    template <typename TokenDef>
    example4_grammar(TokenDef const& tok)
      : example4_grammar::base_type(program)
    {
        using boost::spirit::_val;
        program 
            =  +block
            ;
        block
            =   '{' >> *statement >> '}'
            ;
        statement 
            =   assignment
            |   if_stmt
            |   while_stmt
            ;
        assignment 
            =   (tok.identifier >> '=' >> expression >> ';')
                [
                    std::cout << val("assignment statement to: ") << _1 << "n"
                ]
            ;
        if_stmt
            =   (   tok.if_ >> '(' >> expression >> ')' >> block 
                    >> -(tok.else_ >> block) 
                )
                [
                    std::cout << val("if expression: ") << _2 << "n"
                ]
            ;
        while_stmt 
            =   (tok.while_ >> '(' >> expression >> ')' >> block)
                [
                    std::cout << val("while expression: ") << _2 << "n"
                ]
            ;
        expression 
            =   tok.identifier [ _val = _1 ]
            |   tok.constant   [ _val = _1 ]
            ;
    }
    typedef boost::variant<unsigned int, std::string> expression_type;
    qi::rule<Iterator, qi::in_state_skipper<Lexer> > program, block, statement;
    qi::rule<Iterator, qi::in_state_skipper<Lexer> > assignment, if_stmt;
    qi::rule<Iterator, qi::in_state_skipper<Lexer> > while_stmt;
    qi::rule<Iterator, expression_type(), qi::in_state_skipper<Lexer> >  expression;
};
///////////////////////////////////////////////////////////////////////////////
int main()
{
    typedef std::string::iterator base_iterator_type;
    typedef lex::lexertl::token<base_iterator_type, boost::mpl::vector<unsigned int, std::string> > token_type;
    typedef lex::lexertl::lexer<token_type> lexer_type;
    typedef example4_tokens<lexer_type> example4_tokens;
    typedef example4_tokens::iterator_type iterator_type;
    typedef example4_grammar<iterator_type, example4_tokens::lexer_def> example4_grammar;
    example4_tokens tokens;                         // Our lexer
    example4_grammar calc(tokens);                  // Our parser
    std::string str;
    std::string::iterator it = str.begin();
    iterator_type iter = tokens.begin(it, str.end());
    iterator_type end = tokens.end();
    bool r = qi::phrase_parse(iter, end, calc, qi::in_state("WS")[tokens.self]);
    if (r && iter == end)
    {
        std::cout << "-------------------------n";
        std::cout << "Parsing succeededn";
        std::cout << "-------------------------n";
    }
    else
    {
        std::cout << "-------------------------n";
        std::cout << "Parsing failedn";
        std::cout << "-------------------------n";
    }
    std::cout << "Bye... :-) nn";
    return 0;
}

当我尝试编译它时，我收到了很多错误，请参阅Coliru上的完整列表。

这个例子有什么问题?编译它需要修改什么，为什么需要修改?如何确定哪些编译过程失败?