AFAICT, none that'll affect the TR1 interface. In fact, the TR1 module is just a thin wrapper in V2, perhaps it can be used as is?
There appear to be other problems with the comparison operators, these are required to use only operators == and < on the types held by the tuple, but given: struct strict_comparison1{}; struct strict_comparison2{}; bool operator==(const strict_comparison1&, const strict_comparison1&); bool operator<(const strict_comparison1&, const strict_comparison1&); bool operator==(const strict_comparison2&, const strict_comparison2&); bool operator<(const strict_comparison2&, const strict_comparison2&); bool operator==(const strict_comparison1&, const strict_comparison2&); bool operator<(const strict_comparison1&, const strict_comparison2&); bool operator==(const strict_comparison2&, const strict_comparison1&); bool operator<(const strict_comparison2&, const strict_comparison1&); Then trying to instantiate the operators with: // strict comparisons: const std::tr1::tuple<strict_comparison1, strict_comparison2> comp1, comp2; verify_return_type(comp1 == comp2, false); verify_return_type(comp1 != comp2, false); verify_return_type(comp1 < comp2, false); verify_return_type(comp1 > comp2, false); verify_return_type(comp1 <= comp2, false); verify_return_type(comp1 >= comp2, false); Fails with some extremely criptic error messages in operator!= test_tuple_tricky.cpp c:\data\boost\develop\boost\boost\spirit\fusion\sequence\detail\sequence_not_equal_to.hpp(25) : error C2784: 'disable_if<boost::fusion::is_sequence<Seq1>,bool>::type boost::fusion::operator !=(const Seq1 &,const boost::fusion::sequence_base<Seq2> &)' : could not deduce template argument for 'const boost::fusion::sequence_base<T2> &' from 'const boost::add_const<T>::type' with [ T=boost::mpl::v_at<boost::fusion::tuple_data2<strict_comparison1,strict_comparison2>::types,0>::type ] c:\data\boost\develop\boost\boost\spirit\fusion\sequence\not_equal_to.hpp(46) : see declaration of 'boost::fusion::operator`!='' c:\data\boost\develop\boost\boost\spirit\fusion\sequence\detail\sequence_not_equal_to.hpp(54) : see reference to function template instantiation 'bool boost::fusion::detail::sequence_not_equal_to_detail::call<boost::fusion::detail::sequence_not_equal_to<Seq1,Seq2>,I1,I2>(const T &,const I1 &,const I2 &)' being compiled with [ Seq1=const boost::fusion::tuple2<strict_comparison1,strict_comparison2>, Seq2=const boost::fusion::tuple2<strict_comparison1,strict_comparison2>, I1=boost::fusion::meta::begin<const boost::fusion::tuple2<strict_comparison1,strict_comparison2>>::type, I2=boost::fusion::meta::begin<const boost::fusion::tuple2<strict_comparison1,strict_comparison2>>::type, T=boost::fusion::detail::sequence_not_equal_to<const boost::fusion::tuple2<strict_comparison1,strict_comparison2>,const boost::fusion::tuple2<strict_comparison1,strict_comparison2>> ] c:\data\boost\develop\boost\boost\spirit\fusion\sequence\detail\sequence_not_equal_to.hpp(39) : see reference to function template instantiation 'bool boost::fusion::detail::sequence_not_equal_to<Seq1,Seq2>::call<I1,I2>(const I1 &,const I2 &,boost::mpl::false_)' being compiled with [ Seq1=const boost::fusion::tuple2<strict_comparison1,strict_comparison2>, Seq2=const boost::fusion::tuple2<strict_comparison1,strict_comparison2>, I1=boost::fusion::meta::begin<const boost::fusion::tuple2<strict_comparison1,strict_comparison2>>::type, I2=boost::fusion::meta::begin<const boost::fusion::tuple2<strict_comparison1,strict_comparison2>>::type ] c:\data\boost\develop\boost\boost\spirit\fusion\sequence\not_equal_to.hpp(32) : see reference to function template instantiation 'bool boost::fusion::detail::sequence_not_equal_to<Seq1,Seq2>::call<boost::fusion::meta::begin<Sequence>::type,boost::fusion::meta::begin<Sequence>::type>(const I1 &,const I2 &)' being compiled with [ Seq1=const boost::fusion::tuple2<strict_comparison1,strict_comparison2>, Seq2=const boost::fusion::tuple2<strict_comparison1,strict_comparison2>, Sequence=const boost::fusion::tuple2<strict_comparison1,strict_comparison2>, I1=boost::fusion::meta::begin<const boost::fusion::tuple2<strict_comparison1,strict_comparison2>>::type, I2=boost::fusion::meta::begin<const boost::fusion::tuple2<strict_comparison1,strict_comparison2>>::type ] c:\data\boost\develop\boost\libs\tr1\test\test_tuple_tricky.cpp(93) : see reference to function template instantiation 'bool boost::fusion::operator !=<boost::fusion::tuple2<T0,T1>,boost::fusion::tuple2<T0,T1>>(const boost::fusion::sequence_base<Sequence> &,const boost::fusion::sequence_base<Sequence> &)' being compiled with [ T0=strict_comparison1, T1=strict_comparison2, Sequence=boost::fusion::tuple2<strict_comparison1,strict_comparison2> ] c:\data\boost\develop\boost\boost\spirit\fusion\sequence\detail\sequence_not_equal_to.hpp And then many more like that. Any ideas? Note I haven't got around to attemping mixed sequence comparisons yet, so comparing tuple<strict_compare1, strict_compare2> and tuple<strict_compare2, strict_compare1> should also work OK, and again only invoke operators == and <. Regards, John.