Window crashes when closing a window

[HanProg]

im using SFML 2.4 and Code::blocks as IDE and also glew+glm

i've followed Hopson's tutorial on how to make minecraft in c++ with sfml
and then on closing the window i get an error like "segmentation error"

code for display.cpp

(click to show/hide)

#include "Display.h"
#include <memory>

#include <SFML/Graphics.hpp>
#include <GL/glew.h>
#include <iostream>
namespace Display
{
    std::unique_ptr<sf::RenderWindow> window;
    void init()
    {
        constexpr static int WIDTH = 800;
        constexpr static int HEIGHT = 600;
        sf::ContextSettings settings;
        settings.depthBits = 24;
        settings.majorVersion = 3;
        settings.minorVersion = 3; // means OpenGL 3.3

        window = std::make_unique<sf::RenderWindow>(sf::VideoMode(WIDTH, HEIGHT),
                                                    "OpenGL Window",
                                                    sf::Style::Close,
                                                    settings);

        glewInit();
        glViewport(0, 0, WIDTH, HEIGHT);
    }

    void close()
    {
        window->close();
    }

    void clear()
    {
        glClearColor(0.0, 0.0, 0.0, 1.0);
        glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
    }

    void update()
    {
        window->display();
    }

    void checkForClose()
    {
        //std::cout << "Checking for close.." << std::endl;
        sf::Event e;
        while(window->pollEvent(e))
        {
            if (e.type == sf::Event::Closed)
            {
                std::cout << "closing.." << std::endl;
                close();
                std::cout << "Successfully executed close();" << std::endl;
            }
        }
    }

    bool isOpen()
    {
        return window->isOpen();
    }

}

and code for display.h

(click to show/hide)

#ifndef DISPLAY_H_INCLUDED
#define DISPLAY_H_INCLUDED

namespace Display
{
    void init();
    void close();

    void clear();
    void update();

    void checkForClose();
    bool isOpen();
}

#endif // DISPLAY_H_INCLUDED

[eXpl0it3r]

Don't use hlobal SFML resources (i.e. your global window unique_ptr).

Manually dispose the unique_ptr before leaving main.