How to initialize a private static const map in C++?

Question

I need just dictionary or associative array string => int.

There is type map C++ for this case.

But I need only one map forall instances(-> static) and this map can't be changed(-> const);

I have found this way with boost library

 std::map<int, char> example = 
      boost::assign::map_list_of(1, 'a') (2, 'b') (3, 'c');

Is there other solution without this lib? I have tried something like this, but there are always some issues with map initialization.

class myClass{
private:
    static map<int,int> create_map()
        {
          map<int,int> m;
          m[1] = 2;
          m[3] = 4;
          m[5] = 6;
          return m;
        }
    static map<int,int> myMap =  create_map();

};

Answer 1

#include <map>
using namespace std;

struct A{
    static map<int,int> create_map()
        {
          map<int,int> m;
          m[1] = 2;
          m[3] = 4;
          m[5] = 6;
          return m;
        }
    static const map<int,int> myMap;

};

const map<int,int> A:: myMap =  A::create_map();

int main() {
}