#include <iostream>
#include <memory>
#include <map>


using namespace std;

class Model {
    string s;
public:
    static int cnt;
    Model(const string& s) : s(s) {
        // Load model from file.
        cout << "Loading model: " << s << endl;
        cnt += 1;
    }
};

int Model::cnt = 0;

class ModelFactory {
    map<string, shared_ptr<Model>> cache;
public:
    shared_ptr<Model> get_model(const string& s) {
        auto it = cache.find(s);
        if (it == cache.end()) {
            auto ret = make_shared<Model>(s);
            cache[s] = ret;
            return ret;
        }

        return it->second;
    }
};

struct Monster {
public:
    int x;
    int y;
    shared_ptr<Model> t;
};


int main() {
    ModelFactory f;
    Monster m1{1, 1, f.get_model("pikachu")};
    Monster m2{2, 1, f.get_model("pikachu")};
    Monster m3{1, 2, f.get_model("snorlax")};
    Monster m4{2, 2, f.get_model("pikachu")};

    cout << "Create " << Model::cnt << " models in memory" << endl;
}