On 6/21/2012 10:00 AM, Daniel Larimer wrote:
On Jun 20, 2012, at 9:57 PM, Daniel Larimer wrote:
On Jun 20, 2012, at 7:36 PM, Joel de Guzman wrote:
On 6/20/2012 1:37 PM, Daniel Larimer wrote:
I recently attempted to update to gcc 4.7 and code that compiled with 4.5.3 broke.
It appears that boost::fusion expects boost::fusion::random_access_traversal_tag to implicitly cast to mpl::bool_<false>.
Switching the 3rd argument from mpl::bool_<false> to an extra template arg (that was ignored), seems to fix the compilation errors.
Compiled with std=c++11
Do you have a minimal test case?
#include<boost/fusion/container/vector.hpp> #include<boost/fusion/algorithm.hpp> #include<boost/fusion/include/make_vector.hpp>
struct visitor { template<typename T> void operator()( T t )const{} };
int main() { visitor v; boost::fusion::for_each( boost::fusion::make_vector(5,6.6), v ); return 0; }
I could get things to compile by editing boost/fusion/algorithm/iteration/detail/for_each.hpp and changing the last parameter to Ty. It appears that parameter was ignored anyway and that we didn't care about the type.
template<typename Sequence, typename F, typename Ty> inline void for_each(Sequence& seq, F const& f, Ty) // unsegmented implementation { detail::for_each_dispatch(seq, f, typename traits::category_of<Sequence>::type()); }
No, that is not a proper fix. It just bypasses the problem, which seems to be a gcc 4.7 problem. There is nothing wrong with Fusion code AFAICT. Fusion does not expect boost::fusion::random_access_traversal_tag to be converted to an mpl::bool_<false>. That function (detail::for_each) is called this way: detail::for_each(seq, f, typename traits::is_segmented<Sequence>::type()); And there is nothing wrong with that code AFAICT. Sorry, I do not have gcc 4.7 ATM, but at any rate, what errors do you get with the code above. Both VC10 and gcc-4.6 compiles it just fine. Your previous error report is very suspicious: /usr/local/include/boost/fusion/algorithm/iteration/for_each.hpp:32:9: error: no matching function for call to 'for_each(boost::fusion::vector2< double, double>&, const mace::rpc::detail::unpack_sequence<mace::rpc:: function_filter<mace::rpc::connection<mace::rpc::json::io> > >&, boost::fusion::detail::fusion_category_of<boost::fusion::vector2< double, double> >::type)' Fusion never calls for_each with fusion_category_of. It calls for_each_dispatch, (not for_each) with fusion_category_of as third parameter. I don't know how that happened. Regards, -- Joel de Guzman http://www.boostpro.com http://boost-spirit.com