Let us start here, from square one. No, from Zero!

rawinput/hotplug.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <windows.h>
+
+namespace rawinput {
+
+    class RawInputManager;
+
+    class HotplugManager {
+    private:
+        RawInputManager *ri_mgr;
+        HANDLE hotplug_hid;
+
+    public:
+        HotplugManager(RawInputManager *ri_mgr, HWND hwnd);
+        ~HotplugManager();
+
+        LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
+    };
+}