Boost Fusion compile failure when number of arguments to BOOST_FUSION_ADAPT_STRUCT is 2

Question

Why does this fail to compile with g++ -c filename.cpp:

#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix_core.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
#include <boost/spirit/include/phoenix_object.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <boost/fusion/include/io.hpp>
#include <boost/lambda/lambda.hpp>
#include <boost/spirit/include/phoenix_stl.hpp>
#include <boost/variant/variant.hpp>
#include <iostream>

namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
namespace phoenix = boost::phoenix;
namespace lambda = boost::lambda;

using namespace std;


struct Intensity
{
    int intensity_;
};

BOOST_FUSION_ADAPT_STRUCT(
    Intensity,
    (int, intensity_)
)

template <typename Iterator>
struct InternalParser : qi::grammar<Iterator, Intensity(), ascii::space_type>
{
    InternalParser() : InternalParser::base_type(intensity)
    {
        intensity %= qi::int_;
    }
    qi::rule<Iterator, Intensity(), ascii::space_type> intensity;
};

typedef InternalParser<string::const_iterator> TheParser;

TheParser parser;

But if I add a new field to the struct Intensity it works:

#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix_core.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
#include <boost/spirit/include/phoenix_object.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <boost/fusion/include/io.hpp>
#include <boost/lambda/lambda.hpp>
#include <boost/spirit/include/phoenix_stl.hpp>
#include <boost/variant/variant.hpp>
#include <iostream>

namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
namespace phoenix = boost::phoenix;
namespace lambda = boost::lambda;

using namespace std;


struct Intensity
{
    int dummy_;
    int intensity_;
};

BOOST_FUSION_ADAPT_STRUCT(
    Intensity,
    (int, dummy_)
    (int, intensity_)
)

template <typename Iterator>
struct InternalParser : qi::grammar<Iterator, Intensity(), ascii::space_type>
{
    InternalParser() : InternalParser::base_type(intensity)
    {
        intensity %= qi::int_ >> qi::int_;
    }
    qi::rule<Iterator, Intensity(), ascii::space_type> intensity;
};

typedef InternalParser<string::const_iterator> TheParser;

TheParser parser;

Version of g++: gcc version 4.4.6 20110731 (Red Hat 4.4.6-3) (GCC)

Boost version: 1.41.0

Answer 1

It's a bug in boost 1.41.0. I compiled the 1st example with 1.49.0 and it worked.