I reviewed the serialization/variant.hpp. My reaction is: a) Its pretty hard to understand. b) I like it. c) It seems to satisfy all the requirements we wanted. d) I ran the test on my VC 7.1 system and it worked fine e) I made a few cosmetic changes - just to make it look like the rest of serialization code and checked it into CVS Since I made these changes you should check the versions in the main CVS if you want to match up the line numbers. There's still work to be done however - welcome to boost Here is what I get when I try to compile with gcc 3.3: test_variant.cpp Linking to lib file: libboost_serialization-vc6-mt-gd-1_32.lib C:\BoostMainCVS\boost/serialization/variant.hpp(118) : error C2780: 'class boost::_bi::bind_t<R,class boost::_mfi::dm<R,T>,class boost::_bi::list1<class boost::_bi::value<R> > > __cdecl boost::bind(R T::*,A1)' : expects 2 arguments - 3 provided C:\BoostMainCVS\boost/bind.hpp(1501) : see declaration of 'bind' C:\BoostMainCVS\boost/serialization/split_free.hpp(44) : see reference to function template instantiation 'void __cdecl boost::serialization::save(class boost::archive::binary_oarchive &,const class boost::variant<bool,float,int,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct boost::detail::variant::void4,struct boost::detail::variant::void5,struct boost::detail::variant::void6,struct boost::detail::variant::void7,struct boost::detail::variant::void8,struct boost::detail::variant::void9,struct boost::detail::variant::void10,struct boost::detail::variant::void11,struct boost::detail::variant::void12,struct boost::detail::variant::void13,struct boost::detail::variant::void14,struct boost::detail::variant::void15,struct boost::detail::variant::void16,struct boost::detail::variant::void17,struct boost::detail::variant::void18,struct boost::detail::variant::void19> &,unsigned int)' being compiled C:\BoostMainCVS\boost/serialization/variant.hpp(118) : error C2780: 'class boost::_bi::bind_t<R,struct boost::_mfi::cmf8<R,T,B1,B2,B3,B4,B5,B6,B7,B8>,class boost::_bi::list9<class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R> >
__cdecl boost::bind(R (__thiscall T::*)(B1,B2,B3,B4,B5,B6,B7,B8) const,A1,A2,A3,A4,A5,A6,A7,A8,A9)' : expects 10 arguments - 3 provided C:\BoostMainCVS\boost/bind/bind_mf_cc.hpp(222) : see declaration of 'bind' C:\BoostMainCVS\boost/serialization/split_free.hpp(44) : see reference to function template instantiation 'void __cdecl boost::serialization::save(class boost::archive::binary_oarchive &,const class boost::variant<bool,float,int,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct boost::detail::variant::void4,struct boost::detail::variant::void5,struct boost::detail::variant::void6,struct boost::detail::variant::void7,struct boost::detail::variant::void8,struct boost::detail::variant::void9,struct boost::detail::variant::void10,struct boost::detail::variant::void11,struct boost::detail::variant::void12,struct boost::detail::variant::void13,struct boost::detail::variant::void14,struct boost::detail::variant::void15,struct boost::detail::variant::void16,struct boost::detail::variant::void17,struct boost::detail::variant::void18,struct boost::detail::variant::void19> &,unsigned int)' being compiled C:\BoostMainCVS\boost/serialization/variant.hpp(118) : error C2780: 'class boost::_bi::bind_t<R,struct boost::_mfi::mf8<R,T,B1,B2,B3,B4,B5,B6,B7,B8>,class boost::_bi::list9<class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R> > __cdecl boost::bind(R (__thiscall T::*)(B1,B2,B3,B4,B5,B6,B7,B8),A1,A2,A3,A4,A5,A6,A7,A8,A9)' : expects 10 arguments - 3 provided C:\BoostMainCVS\boost/bind/bind_mf_cc.hpp(211) : see declaration of 'bind' C:\BoostMainCVS\boost/serialization/split_free.hpp(44) : see reference to function template instantiation 'void __cdecl boost::serialization::save(class boost::archive::binary_oarchive &,const class boost::variant<bool,float,int,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct boost::detail::variant::void4,struct boost::detail::variant::void5,struct boost::detail::variant::void6,struct boost::detail::variant::void7,struct boost::detail::variant::void8,struct boost::detail::variant::void9,struct boost::detail::variant::void10,struct boost::detail::variant::void11,struct boost::detail::variant::void12,struct boost::detail::variant::void13,struct boost::detail::variant::void14,struct boost::detail::variant::void15,struct boost::detail::variant::void16,struct boost::detail::variant::void17,struct boost::detail::variant::void18,struct boost::detail::variant::void19> &,unsigned int)' being compiled C:\BoostMainCVS\boost/serialization/variant.hpp(118) : error C2780: 'class boost::_bi::bind_t<R,struct boost::_mfi::cmf7<R,T,B1,B2,B3,B4,B5,B6,B7>,class boost::_bi::list8<class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R> > > __cdecl boost::bind(R (__thiscall T::*)(B1,B2,B3,B4,B5,B6,B7) const,A1,A2,A3,A4,A5,A6,A7,A8)' : expects 9 arguments - 3 provided C:\BoostMainCVS\boost/bind/bind_mf_cc.hpp(198) : see declaration of 'bind' C:\BoostMainCVS\boost/serialization/split_free.hpp(44) : see reference to function template instantiation 'void __cdecl boost::serialization::save(class boost::archive::binary_oarchive &,const class boost::variant<bool,float,int,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct boost::detail::variant::void4,struct boost::detail::variant::void5,struct boost::detail::variant::void6,struct boost::detail::variant::void7,struct boost::detail::variant::void8,struct boost::detail::variant::void9,struct boost::detail::variant::void10,struct boost::detail::variant::void11,struct boost::detail::variant::void12,struct boost::detail::variant::void13,struct boost::detail::variant::void14,struct boost::detail::variant::void15,struct boost::detail::variant::void16,struct boost::detail::variant::void17,struct boost::detail::variant::void18,struct boost::detail::variant::void19> &,unsigned int)' being compiled C:\BoostMainCVS\boost/serialization/variant.hpp(118) : error C2780: 'class boost::_bi::bind_t<R,struct boost::_mfi::mf7<R,T,B1,B2,B3,B4,B5,B6,B7>,class boost::_bi::list8<class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R> > __cdecl boost::bind(R (__thiscall T::*)(B1,B2,B3,B4,B5,B6,B7),A1,A2,A3,A4,A5,A6,A7,A8)' : expects 9 arguments - 3 provided C:\BoostMainCVS\boost/bind/bind_mf_cc.hpp(187) : see declaration of 'bind' C:\BoostMainCVS\boost/serialization/split_free.hpp(44) : see reference to function template instantiation 'void __cdecl boost::serialization::save(class boost::archive::binary_oarchive &,const class boost::variant<bool,float,int,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct boost::detail::variant::void4,struct boost::detail::variant::void5,struct boost::detail::variant::void6,struct boost::detail::variant::void7,struct boost::detail::variant::void8,struct boost::detail::variant::void9,struct boost::detail::variant::void10,struct boost::detail::variant::void11,struct boost::detail::variant::void12,struct boost::detail::variant::void13,struct boost::detail::variant::void14,struct boost::detail::variant::void15,struct boost::detail::variant::void16,struct boost::detail::variant::void17,struct boost::detail::variant::void18,struct boost::detail::variant::void19> &,unsigned int)' being compiled C:\BoostMainCVS\boost/serialization/variant.hpp(118) : error C2780: 'class boost::_bi::bind_t<R,struct boost::_mfi::cmf6<R,T,B1,B2,B3,B4,B5,B6>,class boost::_bi::list7<class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R>,class boost::_bi::value<R> > > __cdecl boost::bind(R (__thiscall T::*)(B1,B2,B3,B4,B5,B6) const,A1,A2,A3,A4,A5,A6,A7)' : expects 8 arguments - 3 provided C:\BoostMainCVS\boost/bind/bind_mf_cc.hpp(174) : see declaration of 'bind' C:\BoostMainCVS\boost/serialization/split_free.hpp(44) : see reference to function template instantiation 'void __cdecl boost::serialization::save(class boost::archive::binary_oarchive &,const class boost::variant<bool,float,int,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct boost::detail::variant::void4,struct boost::detail::variant::void5,struct boost::detail::variant::void6,struct boost::detail::variant::void7,struct boost::detail::variant::void8,struct boost::detail::variant::void9,struct boost::detail::variant::void10,struct boost::detail::variant::void11,struct boost::detail::variant::void12,struct boost::detail::variant::void13,struct boost::detail::variant::void14,struct boost::detail::variant::void15,struct boost::detail::variant::void16,struct boost::detail::variant::void17,struct boost::detail::variant::void18,struct boost::detail::variant::void19> &,unsigned int)' being compiled C:\BoostMainCVS\boost/serialization/variant.hpp(118) : error C2780: 'class boost::_bi::bind_t<R,struct boost::_mfi::mf6<R,T,B1,B2,B3,B4,B5,B6>,class boost::_bi::list7<class boost::_bi::value<R>,class boost::_bi::value<R>,class...
Here is what I get when I try to compile with VC 8.0: Run output:../../../libs/serialization/test/test_variant.cpp(58): error in "call_test_main": test gets_written == got_read failed [6.4 != 6.4] *** 1 failure detected in test case "call_test_main" EXIT STATUS: 201 Borland also gives compile errors: Error E2401 C:\BoostMainCVS\boost/variant/detail/substitute_fwd.hpp 50: Invalid template argument list Error E2041 C:\BoostMainCVS\boost/variant/detail/substitute_fwd.hpp 50: Incorrect use of default Error E2040 C:\BoostMainCVS\boost/variant/detail/substitute_fwd.hpp 50: Declaration terminated incorrectly Error E2394 C:\BoostMainCVS\boost/variant/detail/substitute.hpp 101: Too few arguments passed to template 'substitute<T,Dest,Source,Arity>' Error E2040 C:\BoostMainCVS\boost/variant/detail/substitute.hpp 101: Declaration terminated incorrectly Error E2228 C:\BoostMainCVS\boost/variant/detail/substitute.hpp 101: Too many error or warning messages Robert Ramey