Multiple Window Handling wrapper class : header file for C++

Env.h

//  Derived from: GLFW call to non-static class function in static key_callback
//  https://stackoverflow.com/a/62692209/14376181
//

#ifndef ENV_H
#define ENV_H

#include <GLFW/glfw3.h>
#include <direct.h>
#include <filesystem>
#include <iostream>

class Viewer {
   public:
    GLFWwindow* window;

    Viewer(std::string title) {
        glfwInit();
        window = glfwCreateWindow(640, 480, title.c_str(), NULL, NULL);
        glfwMakeContextCurrent(window);
    }

    static void keyCallbackWrapper(GLFWwindow* window, int key, int scancode, int action, int mods) {
        Viewer* viewer = static_cast<Viewer*>(glfwGetWindowUserPointer(window));
        viewer->keyCallback(window, key, scancode, action, mods);
    }

    void keyCallback(GLFWwindow* window, int key, int scancode, int action, int mods) {
        // basic window handling
        if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) {
            std::cout << "exiting..." << std::endl;
            glfwSetWindowShouldClose(window, GL_TRUE);
        }
        if (key == GLFW_KEY_SPACE && action == GLFW_PRESS) {
            std::cout << "Space bar..." << std::endl;
        }
    }
};

class Env : public Viewer {
   public:
    Env(std::string title) : Viewer(title) {

        // my viewer specific state gets initialized here
        glfwSetWindowUserPointer(this->window, this);
        glfwSetKeyCallback(this->window, Viewer::keyCallbackWrapper);
    };

    void RenderLoop() {
        while (!glfwWindowShouldClose(this->window)) {
            
            // update function gets called here
            update();

            glfwPollEvents();
            glfwSwapBuffers(this->window);
        }
        glfwTerminate();
    }
  void update(){
    // do something while the window is not closed...
  
  }
};
#endif  // ENV_H


// Example usage
int main(){
  Env env("My Window");
  return 0;
}