JOAQUIN LOPEZ MU?Z <joaquin <at> tid.es> writes:
OK, I've carefully read the standard and I understand now that convertiblity between X and itself is tantamount to X being copy constructible (my naive understanding was that X is always convertible to X by definition.) For the purposes of my code, I can then replace the calls of the form
is_convertible<X,Y>
with calls to
template<typename From,typename From> struct is_same_or_convertible: mpl::or_< is_same<From,To> is_convertible<From,To> > {};
and thus avoid executing is_convertible<From,To> whith From=To.
I checked this fix (having fixed some obvious typos in it) out with the test case I posted earlier (in multi_index problem thread) - it doesn't help (sigh). The error is: D:\src\3rd-parties\boost/boost/type_traits/is_convertible.hpp(254): error: no suitable user-defined conversion from "const name_record" to "const base_record" exists BOOST_STATIC_CONSTANT(bool, value = ^ detected during: instantiation of class "boost::detail::is_convertible_basic_impl<From, To> [with From=boost::detail::is_convertible_impl<const name_record, const base_record>::ref_type, To=const base_record]" at line 286 instantiation of class "boost::detail::is_convertible_impl<From, To> [with From=const name_record, To=const base_record]" at line 362 instantiation of class "boost::detail::is_convertible_impl_dispatch<From, To> [with From=const name_record, To=const base_record]" at line 409 instantiation of class "boost::is_convertible<From, To> [with From=const name_record, To=const base_record]" at line 25 of "D:\src\3rd- parties\boost/boost/mpl/aux_/preprocessed/plain/or.hpp" instantiation of class "boost::mpl::aux::or_impl<false, T1, T2, T3, T4> [with T1=boost::is_convertible<const name_record, const base_record>, T2=boost::mpl::false_, T3=boost::mpl::false_, T4=boost::mpl::false_]" at line 50 of "D:\src\3rd-parties\boost/boost/mpl/aux_/preprocessed/plain/or.hpp"