What if C++ were a scripting language that you could eval from your native C++?

ChaiScript: http://chaiscript.com

Example (from the homepage):

#include <chaiscript/chaiscript.hpp>

std::string helloWorld(const std::string &t_name)
{
  return "Hello " + t_name + "!";
}

int main()
{
  chaiscript::ChaiScript chai;
  chai.add(chaiscript::fun(&helloWorld), 
           "helloWorld");

  chai.eval("puts(helloWorld("Bob"));");
}