সি++ merge

#include <iostream>
#include <map>
using namespace std;

int main() {
  map<string, string> user = {
      {"নাম", "মোঃ আরিফ"}
  };

  map<string, string> info = {
      {"দেশ", "বাংলাদেশ"}
  };

  user.merge(info);

  for (const auto& item : user) {
      cout << item.first << ": " << item.second << endl;
  }
}