[Boost-bugs] [Boost C++ Libraries] #7503: for_each does not compile with g++-4.7.1

Subject: [Boost-bugs] [Boost C++ Libraries] #7503: for_each does not compile with g++-4.7.1
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-10-13 21:41:52

#7503: for_each does not compile with g++-4.7.1
-----------------------------------------+----------------------------------
 Reporter:  veso <vveesskkoo@…>          |       Owner:  djowel 
     Type:  Bugs                         |      Status:  new    
Milestone:  Boost 1.52.0                 |   Component:  fusion 
  Version:  Boost 1.51.0                 |    Severity:  Problem
 Keywords:                               |  
-----------------------------------------+----------------------------------
 Hello,

 The following code works fine with g++-4.4 and can not compile with
 g++-4.7.1.

 #include    <iostream>
 #include    <string>
 #include    <type_traits>
 #include    <typeinfo>

 #include    <boost/fusion/include/map.hpp>
 #include    <boost/fusion/include/filter_if.hpp>
 #include    <boost/fusion/include/for_each.hpp>

 namespace fusion = boost::fusion;

 template<typename Key_Base_T, typename Pair_T>
 struct is_same_key: public std::is_same<Key_Base_T, typename
 Pair_T::first_type> {};

 struct print_ftor {
     template<typename Key_T, typename Value_T>
     inline void
     operator()(const boost::fusion::pair<Key_T, Value_T>& pair) const {
         std::cout << "type: " << typeid(Key_T).name() << ", value: " <<
 pair.second << std::endl;
     }
 };

 int main () {

     typedef fusion::map<    fusion::pair<int, char>,
                             fusion::pair<double, std::string>   >
             map_type;

     map_type map_sequence(  fusion::make_pair<int>('X'),
                             fusion::make_pair<double>("Men")    );

     fusion::for_each(   fusion::filter_if< is_same_key< double,
 boost::mpl::_1> >(map_sequence),
                         print_ftor());

     return 0;
 }


 The error which the compiler produces is:

 g++-4.7 -o test -std=c++0x -Wall -pedantic
 -I/home/veso/boost_1_52_0_beta1  main.c++
 main.c++: In instantiation of ‘struct is_same_key<double, mpl_::arg<1> >’:
 /home/veso/boost_1_52_0_beta1/boost/fusion/algorithm/iteration/detail/for_each.hpp:32:9:
 required from ‘void boost::fusion::detail::for_each_linear(const First&,
 const Last&, const F&, mpl_::false_) [with First =
 boost::fusion::filter_iterator<boost::mpl::inherit2<boost::fusion::forward_traversal_tag,
 boost::fusion::associative_tag>,
 boost::fusion::basic_iterator<boost::fusion::map_iterator_tag,
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >::category, const
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >, 0>,
 boost::fusion::basic_iterator<boost::fusion::map_iterator_tag,
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >::category, const
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >, 2>,
 is_same_key<double, mpl_::arg<1> > >; Last =
 boost::fusion::filter_iterator<boost::mpl::inherit2<boost::fusion::forward_traversal_tag,
 boost::fusion::associative_tag>,
 boost::fusion::basic_iterator<boost::fusion::map_iterator_tag,
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >::category, const
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >, 2>,
 boost::fusion::basic_iterator<boost::fusion::map_iterator_tag,
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >::category, const
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >, 2>,
 is_same_key<double, mpl_::arg<1> > >; F = print_ftor; mpl_::false_ =
 mpl_::bool_<false>]’
 /home/veso/boost_1_52_0_beta1/boost/fusion/algorithm/iteration/detail/for_each.hpp:42:9:
 required from ‘void boost::fusion::detail::for_each_dispatch(Sequence&,
 const F&, Tag) [with Sequence = const boost::fusion::filter_view<const
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >,
 is_same_key<double, mpl_::arg<1> > >; F = print_ftor; Tag =
 boost::mpl::inherit2<boost::fusion::forward_traversal_tag,
 boost::fusion::associative_tag>]’
 /home/veso/boost_1_52_0_beta1/boost/fusion/algorithm/iteration/detail/for_each.hpp:132:9:
 required from ‘void boost::fusion::detail::for_each(Sequence&, const F&,
 mpl_::false_) [with Sequence = const boost::fusion::filter_view<const
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >,
 is_same_key<double, mpl_::arg<1> > >; F = print_ftor; mpl_::false_ =
 mpl_::bool_<false>]’
 /home/veso/boost_1_52_0_beta1/boost/fusion/algorithm/iteration/for_each.hpp:49:9:
 required from ‘typename
 boost::enable_if<boost::fusion::traits::is_sequence<Sequence>, void>::type
 boost::fusion::for_each(const Sequence&, const F&) [with Sequence =
 boost::fusion::filter_view<const
 boost::fusion::map<boost::fusion::pair<int, char>,
 boost::fusion::pair<double, std::basic_string<char> > >,
 is_same_key<double, mpl_::arg<1> > >; F = print_ftor; typename
 boost::enable_if<boost::fusion::traits::is_sequence<Sequence>, void>::type
 = void]’
 main.c++:33:19:   required from here
 main.c++:13:8: error: no type named ‘first_type’ in ‘struct mpl_::arg<1>’
 make: *** [all] Error 1


 For the test I used Debian stable with g++-4.7 installed from the backport
 repository.

 The bug appears with boost versions 1.42, 1.51, 1.51beta1

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7503>
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