Larry Evans a écrit :
... generating a container of : std::pair< const std::type_info *, boost::any >
But boost::any::type() returns std::type_info const&:
http://www.boost.org/doc/html/boost/any.html#id717459-bb
wouldn't that make the above pair contain redundant information?
In this specific case, yes (Using type_info & as a key is mandatory only when 'assembling' different properties types at run-time) . Now, imagine that you wish to apply another operation than 'any' to all members of an object, the first example to jumps to my mind is the transformation into a XML tag. You would have something like that: template< typename Struct, typename Type, typename Struct::*Member > struct ToXml { static std::string make_tag( const Struct & anObj ) { return "<" + std::string( typeid(Member) + ">" + to_string( anObj->*Member ) + "</" + std::string( typeid(Member) + ">" ; }; Now, you can put these objects in the same list because they have the same type: std::pair< const std::type_info *, &ToXml< myStruct, Type1, Struct::Field1 >::make_tag > std::pair< const std::type_info *, &ToXml< myStruct, Type2, Struct::Field2 >::make_tag > With such a list, plus an object of type Struct, you can apply 'toXml' to all members of the object. And if you need a very specific processing for such or such field, you just need to replace an element in the list. But crd creates the initial list with the compile-time definitions of members (A kind of boost::mpl::tuple ) plus the definition of 'ToXml'.