c++ - How to boost::any_cast into std::string -

i have test snippet

#include <boost/any.hpp> #include <iostream> #include <vector> #include <bitset> #include <string>  class wrapper {   int value;   char character;   std::string str;  public:   wrapper(int i, char c, std::string s) {     value = i;     character = c;     str = s;    }    void get_data(){     std::cout << "value = " << value << std::endl;     std::cout << "character = " << character << std::endl;     std::cout << "string= " << str << std::endl;   } };  int main(){     std::vector<boost::any> container;    container.push_back(10);    container.push_back(1.4);    container.push_back("mayukh");    container.push_back('a');    container.push_back(std::bitset<16>(255) );    wrapper wrap(20, 'm', "alisha");    container.push_back(wrap);     std::cout << boost::any_cast<int>(container[0]) << std::endl;    std::cout << boost::any_cast<double>(container[1]) << std::endl;    std::cout << boost::any_cast<std::string>(container[2]);    std::cout << boost::any_cast<char>(container[3]) << std::endl;    std::cout << boost::any_cast<std::bitset<16>>(container[4]);    auto p = boost::any_cast<wrapper>(container[5]);    p.get_data();  return 0;  } 

in boost::any_cast gives bad_casting exception std::string. means reason not able typecast boost::any std::string. while other classes bitset or own user defined class working. can please tell me why & way out of this?

"mayukh" not std::string, const array of 7 characters {'m', 'a', 'y', 'u', 'k', 'h', '\0'}. in c++14, "mayukh"s std::string after using namespace std::literals::string_literals;.

in c++11, std::string("mayukh") std::string well.

boost::any supports converting exact same type (well, decay/const/etc). not support conversions between types. see boost documentation:

discriminated types contain values of different types not attempt conversion between them, i.e. 5 held strictly int , not implicitly convertible either "5" or 5.0. indifference interpretation awareness of type makes them safe, generic containers of single values, no scope surprises ambiguous conversions.

augmenting any smart conversions can done. example, pseudo-any takes incoming type, , possibly auto-converts (so won't store shorts: converts signed integral types int64_t , unsigned uint64_t, converts "hello" std::string("hello"), etc) before storing it.