message: Return nullptr if window creation fails
diff: @@ -964,7 +964,7 @@ HWND VulkanExampleBase::setupWindow(HINSTANCE hinstance, WNDPROC wndproc)
  }
  else
  {
  - return false;
  + return nullptr;
  }
  }
  }
  @@ -1019,7 +1019,7 @@ HWND VulkanExampleBase::setupWindow(HINSTANCE hinstance, WNDPROC wndproc)
  {
  printf("Could not create window!\n");
  fflush(stdout);
  - return 0;
  + return nullptr;
  exit(1);
  }
  