../../boost_latest/boost/concept_check.hpp: In instantiation of 'boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*>':
../../boost_latest/boost/concept/detail/has_constraints.hpp:42:   instantiated from 'const bool boost::concepts::not_satisfied<boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*> >::value'
../../boost_latest/boost/concept/detail/has_constraints.hpp:45:   instantiated from 'boost::concepts::not_satisfied<boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*> >'
../../boost_latest/boost/mpl/if.hpp:67:   instantiated from 'boost::mpl::if_<boost::concepts::not_satisfied<boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*> >, boost::concepts::constraint<boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*> >, boost::concepts::requirement<boost::concepts::failed************ boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*>::************> >'
../../boost_latest/boost/concept/detail/general.hpp:20:   instantiated from 'boost::concepts::requirement_<void (*)(boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*>)>'
main.cpp:9:   instantiated from here
../../boost_latest/boost/concept_check.hpp:211: error: 'boost::concepts::requirement<boost::concepts::failed************ Model::************>::failed [with Model = boost::concepts::usage_requirements<boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*> >]' is not a valid template argument for type 'void (*)()' because function 'static void boost::concepts::requirement<boost::concepts::failed************ Model::************>::failed() [with Model = boost::concepts::usage_requirements<boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*> >]' has not external linkage
main.cpp: In function 'int main()':
main.cpp:9: error: 'boost::concepts::requirement<boost::concepts::failed************ Model::************>::failed [with Model = boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*>]' is not a valid template argument for type 'void (*)()' because function 'static void boost::concepts::requirement<boost::concepts::failed************ Model::************>::failed() [with Model = boost::Convertible<<unnamed>::Derived*, <unnamed>::Base*>]' has not external linkage
main.cpp:9: error: invalid type in declaration before ';' token