Boost Any provides the class boost::any which like JavaScript variables can store arbitrary types of information.

#include 
     
      #include 
      
       #include 
       
        int main() {  boost::any a = 1;  std::cout << boost::any_cast
        
         (a) << std::endl;  if (!a.empyt()) {    const std::type_info& ti = a.type();    std::cout << ti.name() << std::endl;  }  a = 3.14;  std::cout << boost::any_cast
         
          (a) << std::endl;  a = true;  std::cout << std::boolalpha << boost::any_cast
          
           (a) << std::endl; return 0;}
          
         
        
       
      
     

Variables of type boost::any are not completely unlimited in what they can store; Any value stored in a variable of type boost::any must be copy-constructible.

By passing the appropriate type as a template parameter to boost::any_cast, the value of the variable is converted. If an invalid type is specified, an exception of type boost::bad_any_cast will be thrown.

To check whether or not a variable of type boost::any contains information, use the member function empty(). To check the type of the stored information, use the member function type().