Now that 32-bit systems are slowly dying out, more and more people try to compile WinBoard as 64-bit application. And it seems there are some issues there. One of those seems to be the use of SetWindowLong / GetWindowLong. People reported they could only compile on MSVC when they replaced this by SetWindowLongPtr / GetWindowLongPtr.
I am not sure if this formal distinction between copying integers or pointers already exists in 32-bit Windows (where these have equal size). If so, it would be harmless to switch to the xxxPtr versions of these API calls generally. I am not sure that we would have to replace it everywhere. Some calls seem to fetch non-pointer data (GWL_STYLE, GWL_USERDATA). GWL_WNDPROC is obviously an address, and I am not sure what GWL_ID is, and GWL_HINSTANCE is probably a pointer as well.
