I striped the sample down to: typedef make_recursive_variant<int, std::pair<int, recursive_variant_> >::type value; value v; Which compiles fine with MS VC 7.1 and fails to compile on Intel C++ 8. Here is Intel output: C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7/include/utility(51): error: incomplete type is not allowed _Ty2 second; // the second stored value ^ detected during: instantiation of class "std::pair<_Ty1, _Ty2> [with _Ty1=int, _Ty2=boost::recursive_variant_]" at line 252 of "D:\lib\boost\boost/variant/detail/visitation_impl.hpp" instantiation of "Visitor::result_type boost::detail::variant::visitation_impl(const int, const int, Visitor &, VoidPtrCV, boost::mpl::false_, NoBackupFlag, Which *, step0 *) [with Which=boost::mpl::int_<0>, step0=boost::detail::variant::visitation_impl_step<boost::mpl::begin<boo st::variant<boost::detail::variant::recursive_flag<int>, std::pair<int, boost::recursive_variant_>, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>::recursive_enabled_types>::type, boost::mpl::end<boost::variant<boost::detail::variant::recursive_flag<in t>, std::pair<int, boost::recursive_variant_>, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>::recursive_enabled_types>::type>, Visitor=boost::detail::variant::destroyer, VoidPtrCV=void *, NoBackupFlag=boost::variant<boost::detail::variant::recursive_flag<int>, std::pair<int, boost::recursive_variant_>, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>::has_fallback_type_]" at line 1738 of "D:\lib\boost\boost/variant/variant.hpp" instantiation of "Visitor::result_type boost::variant<T0_, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19>::internal_apply_visitor_impl(int, int, Visitor &, VoidPtrCV) [with T0_=boost::detail::variant::recursive_flag<int>, T1=std::pair<int, boost::recursive_variant_>, T2=boost::detail::variant::void_, T3=boost::detail::variant::void_, T4=boost::detail::variant::void_, T5=boost::detail::variant::void_, T6=boost::detail::variant::void_, T7=boost::detail::variant::void_, T8=boost::detail::variant::void_, T9=boost::detail::variant::void_, T10=boost::detail::variant::void_, T11=boost::detail::variant::void_, T12=boost::detail::variant::void_, T13=boost::detail::variant::void_, T14=boost::detail::variant::void_, T15=boost::detail::variant::void_, T16=boost::detail::variant::void_, T17=boost::detail::variant::void_, T18=boost::detail::variant::void_, T19=boost::detail::variant::void_, Visitor=boost::detail::variant::destroyer, VoidPtrCV=void *]" at line 1749 of "D:\lib\boost\boost/variant/variant.hpp" instantiation of "Visitor::result_type boost::variant<T0_, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19>::internal_apply_visitor(Visitor &) [with T0_=boost::detail::variant::recursive_flag<int>, T1=std::pair<int, boost::recursive_variant_>, T2=boost::detail::variant::void_, T3=boost::detail::variant::void_, T4=boost::detail::variant::void_, T5=boost::detail::variant::void_, T6=boost::detail::variant::void_, T7=boost::detail::variant::void_, T8=boost::detail::variant::void_, T9=boost::detail::variant::void_, T10=boost::detail::variant::void_, T11=boost::detail::variant::void_, T12=boost::detail::variant::void_, T13=boost::detail::variant::void_, T14=boost::detail::variant::void_, T15=boost::detail::variant::void_, T16=boost::detail::variant::void_, T17=boost::detail::variant::void_, T18=boost::detail::variant::void_, T19=boost::detail::variant::void_, Visitor=boost::detail::variant::destroyer]" at line 1157 of "D:\lib\boost\boost/variant/variant.hpp" instantiation of "void boost::variant<T0_, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19>::destroy_content() [with T0_=boost::detail::variant::recursive_flag<int>, T1=std::pair<int, boost::recursive_variant_>, T2=boost::detail::variant::void_, T3=boost::detail::variant::void_, T4=boost::detail::variant::void_, T5=boost::detail::variant::void_, T6=boost::detail::variant::void_, T7=boost::detail::variant::void_, T8=boost::detail::variant::void_, T9=boost::detail::variant::void_, T10=boost::detail::variant::void_, T11=boost::detail::variant::void_, T12=boost::detail::variant::void_, T13=boost::detail::variant::void_, T14=boost::detail::variant::void_, T15=boost::detail::variant::void_, T16=boost::detail::variant::void_, T17=boost::detail::variant::void_, T18=boost::detail::variant::void_, T19=boost::detail::variant::void_]" at line 1164 of "D:\lib\boost\boost/variant/variant.hpp" instantiation of "boost::variant<T0_, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19>::~variant() [with T0_=boost::detail::variant::recursive_flag<int>, T1=std::pair<int, boost::recursive_variant_>, T2=boost::detail::variant::void_, T3=boost::detail::variant::void_, T4=boost::detail::variant::void_, T5=boost::detail::variant::void_, T6=boost::detail::variant::void_, T7=boost::detail::variant::void_, T8=boost::detail::variant::void_, T9=boost::detail::variant::void_, T10=boost::detail::variant::void_, T11=boost::detail::variant::void_, T12=boost::detail::variant::void_, T13=boost::detail::variant::void_, T14=boost::detail::variant::void_, T15=boost::detail::variant::void_, T16=boost::detail::variant::void_, T17=boost::detail::variant::void_, T18=boost::detail::variant::void_, T19=boost::detail::variant::void_]"
-----Original Message----- From: Caleb Epstein [mailto:caleb.epstein@gmail.com] Sent: Thursday, November 04, 2004 9:00 PM To: boost@lists.boost.org; Maxim Yegorushkin Subject: const_string + recursive_variant = boom
I've been trying to build a generic "message" type class using boost.variant and have just run across a problem when trying to convert it from using std::string to using the proposed boost::const_string.
Attached is a small test case and the output from gcc 3.3.2 (the latter gzipped due to its hugeness). All is well if the mystring type is std::string.
Any thoughts on how to fix this?
-- Caleb Epstein caleb.epstein@gmail.com