Why does GLFW window throw access violation only if abstracted to a unique pointer?

I’m trying to use GLFW inside a static library. If I initialize a GLFW window inside the library’s primary function (Application), it works. But if I abstract it to a separate class, I get an access violation error. I’ve linked glfw to both the library and the executable:

#include "glad/glad.h"
#include "glfw3.h"
#include "Window/Window.h"
Application::Application() : m_Camera(1.0f, 1.0f, 1.0f, 1.0f) {
    std::unique_ptr<Window> m_Window;
    m_Window = std::unique_ptr<Window>();

}

bool Application::init() {
    m_Window->init();} //access violation 

class Window:

bool Window::init() {
    if (!glfwInit()) HZ_CORE_CRITICAL("GLFW FAILED");
    //glfwSetErrorCallback(GLFWErrorCallback);
    m_gWindow = glfwCreateWindow(800, 600, "ALAvery", NULL, NULL);
    if (!m_gWindow) { HZ_CORE_CRITICAL("GLFW WINDOW CREATION FAILED"); return false; }
    glfwMakeContextCurrent(m_gWindow);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 4);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    int status = gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
    HZ_CORE_ASSERT(status, "Failed to initialize Glad!");

>Solution :

You are trying everything except for looking for examples of usage.

Application::Application() : m_Camera(1.0f, 1.0f, 1.0f, 1.0f), m_Window{ new Window }
{
    ;   
}

When you have:

Application::Application() : m_Camera(1.0f, 1.0f, 1.0f, 1.0f) {
    std::unique_ptr<Window> m_Window;     // creating a local variable that shadows class m_Window...
    m_Window = std::unique_ptr<Window>(); // copy assigment of empty unique_ptr (std::unique_ptr<Window>() = default construction of unique_ptr)
}

Basically you did same as if you just deleted those lines and did nothing.

Since the c++17 specification you can also use:

m_Window = std::make_unique<Window>(); 

or:

Application::Application() : m_Camera(1.0f, 1.0f, 1.0f, 1.0f), m_Window{ std::make_unique<Window>() }