Boost C++ Application Development Cookbook - Second Edition

How to do it...

Boost offers a solution, the Boost.Any library, that has an even better syntax:

#include <boost/any.hpp> #include <iostream> #include <vector> #include <string>  int main() {     std::vector<boost::any> some_values;     some_values.push_back(10);     some_values.push_back("Hello there!");     some_values.push_back(std::string("Wow!"));     std::string& s = boost::any_cast<std::string&>(some_values.back());     s += " That is great!";     std::cout << s; } 

Great, isn't it? By the way, it has an empty state, which could be checked using the empty() member function (just like in standard library containers).

You can get the value from boost::any using two approaches:

void example() {    boost::any variable(std::string("Hello world!")); // Following ...