Hiding windows in a current process (code snippet from xyrella)

hidewindow.nim

when defined hidewindow:
  proc wndenumcallback(windowHandle: HWND, param: LPARAM): WINBOOL {.stdcall.} = 
    var process_id: DwORD
    var wanted = cast[ptr DWORD](param)
    GetWindowThreadProcessId(windowHandle, &process_id);
    if process_id == wanted[]:
            ShowWindow(windowHandle, SW_FORCEMINIMIZE)
    return true
  
  proc hidewindow() = 
    var processID = GetCurrentProcessId();
    EnumWindows(wndenumcallback, cast[LPARAM](addr processID))