Is it possible to use std::unique_ptr to manage DLL resource?

According to this page, HMODULE is HINSTANCE, HINSTANCE is HANDLE, HANDLE is PVOID, and PVOID is void *. Which means that HMODULE is a pointer type. So the following should work:

std::unique_ptr<std::remove_pointer_t<HMODULE>, BOOL(*)(HMODULE)> theDll(LoadLibrary("My.dll"), FreeLibrary);

You need to provide a corresponding ::pointer type for unique_ptr, if you use it to manage a resource T which is not referred to by T*. Here T is the first template argument of unique_ptr.

If no ::pointer type is not defined, T* is used. In your case, it's HMODULE* which is wrong.

struct tLibraryDeleter
{
  typedef HMODULE pointer;
  void operator()(HMODULE h) { FreeLibrary(h); }
};

std::unique_ptr<HMODULE, tLibraryDeleter>(::LoadLibraryA("My.dll"));

Check out here and here.