Getting error while using Functors without creating a Functor class?

I want to use functors without creating a functor class but My foundVector is showing empty even if i store a matched string in foundVector.

Also tell me is there any better way to use fucntors

I am using Visual Studio 2013. Here is my demo code:

Input:

#include<iostream>
#include<vector>
#include <string>

class Demo
{
   public:
      Demo(const std::string& string) :string_(string){};
      void findFunctor(const std::string& string);
      void operator()(const std::string &string);
      void input();
   private:
      const std::string string_;
      std::vector<std::string> storeVector;
      std::vector<std::string> foundvector;
};

void Demo::input()
{
   storeVector.push_back("test");
   storeVector.push_back("hello");
   storeVector.push_back("world");
   storeVector.push_back("foo");
   storeVector.push_back("hello");
}

void Demo::findFunctor(const std::string& string)
{
   Demo object(string);
   for (auto &elem : storeVector)
   {
      object(elem);
   }
   for (auto elem : foundvector)
   {
      std::cout << elem<<"\n";//Surprisingly Vector is empty and i want to know why??
   }

}

void Demo::operator()(const std::string &string)
{
   if (string == string_)
   {
      foundvector.push_back(string_);//Vector consists of two strings if  matching string is found
   }
}

int main()
{
   Demo dObject("hello");
   dObject.input();
   dObject.findFunctor("hello");
   return 0;
}