title: lambda function callback returns error : C++ no suitable conversion function from to exists
body: <p>i try to implement simple lambda callback to open source function like this :</p>
  
  <p>i want to pass to the lambda the :  GLFWwindow* window;
  which is defined in the header of GLFWManager</p>
  
  <pre><code>void GLFWManager::handleExitGame()
  {
      glfwSetKeyCallback(window, [this](GLFWwindow* window, int key, int scancode, int action, int mods)-&gt;GLFWkeyfun {
  
          if (key == GLFW_KEY_ESCAPE &amp;&amp; action == GLFW_RELEASE)
          {
  
          }
  
      });
  }
  </code></pre>
  
  <p>the signetures are :</p>
  
  <pre><code>GLFWAPI GLFWkeyfun glfwSetKeyCallback(GLFWwindow* window, GLFWkeyfun callback);
  typedef void (* GLFWkeyfun)(GLFWwindow*,int,int,int,int);
  </code></pre>
  
  <p>i keep getting this compiler error :  </p>
  
  <pre><code>C++ no suitable conversion function from to exists
  </code></pre>