Question

I’m new to C++ and I recently found out that we can initialize a collection of strings by using the following code:

map <string,string> myArray;
myArray["key1"] = "value1";
myArray["key2"] = "value2";

cout<<myArray["key1"]<<endl; //result: value1

But what if I have to assign to key2 not a string but another collection? Here is how I suppose it would look:

map <string, ???another map???> myArray;

map<string,string> secondArray;
secondArray["foo"] = "bar";

myArray["key1"] = "value1";
myArray["key2"] = secondArray;

cout<<myArray["key2"]["foo"]<<endl; //expected result: bar

Is that possible?

Answer 1

As the questioner seems to have accepted one of the answers, this is just a
supplement.
If Boost is allowed, Boost.Variant might meet the purpose.
For example, the following code prints bar as in the question.

#include <boost/variant.hpp>
#include <map>
#include <string>
#include <iostream>

int main() {
  using namespace std;
  using namespace boost;
  typedef map<string,string> map_t;
  map <string, variant<string, map_t> > myArray;

  map_t secondArray;
  secondArray["foo"] = "bar";

  myArray["key1"] = "value1";
  myArray["key2"] = secondArray;

  cout<<get< map_t >( myArray["key2"] )["foo"]<<endl;
}

Here is a test on ideone.