How to register an object using string or int as key dynamically, and store, access it with the key in C++?

I want to design a data dashboard framework with c++ with the following requirements:

1. clients can register data type to the dashboard using a key (string or integer are both acceptable)
2. clients can store/access the object with the known data type and key

The following example code demonstrates how I want to use it

// data.hpp
struct DataA
{
  DataA();
  int a;
};

struct DataF
{
  DataF();
  float f;
};

// data.cpp
static DataA s_da; 
static DataF s_df;

DataA::DataA()
{
  if(!Dashboard::Register("A", s_da)) {
    cerr << "unable to register DataA, key is used";
  }
}

DataF::DataF()
{
  if(!Dashboard::Register("F", s_df)) {
    cerr << "unable to register DataF, key is used";
  }
}


// main.cpp

int main () 
{
  DataA da;
  da.a = 123;
  Dashboard::Set("A", da);

  DataF df;
  df.f = 3.14;
  Dashboard::Set("F", df);

  cout << ((DataA)Dashboard::Get("A")).a << endl; // 123
  cout << ((DataF)Dashboard::Get("F")).f << endl; // 3.14

  return 0;
}

However, I can't come up with any idea to implement the Dashboard class to provide the interface.

How could I dynamically register an object with a given datatype and key? Is there any design pattern that addresses this requirement?