Hi! what do you mean by parent? boost::any does not derive from any other class. Just a note, using that version of cast: boost::any_cast<a*>(&any); or boost::any_cast<a const*>(&any); will not throw, but return a null pointer if any does not contain the expected type. Consider using boost::variant, which supports visitor-pattern for dispatching. Best Regards, Ovanes On Mon, Nov 23, 2009 at 5:18 PM, Yan Cheng Cheok <yccheok@yahoo.com> wrote:
May I know is there any way to determine parent class from boost::any?
#include <iostream> #include <boost/any.hpp>
class a { public: virtual ~a() {} };
class b : public a { };
bool is_class_a(const boost::any& any) { return boost::any_cast<a>(&any) != 0; }
bool is_class_a_v2(const boost::any& any) { try { boost::any_cast<a>(any); return true; } catch(const boost::bad_any_cast &) { return false; } }
int main() { std::cout<< is_class_a(b())<< std::endl; // return 0. but i wish to return 1. std::cout<< is_class_a(a())<< std::endl; // return 1.
std::cout<< is_class_a_v2(b())<< std::endl; // return 0. but i wish to return 1. std::cout<< is_class_a_v2(a())<< std::endl; // return 1. }
_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users