How can I tell that a directory is really a recycle bin?

#include <windows.h>
#include <shlobj.h>
#include <tchar.h>
#include <stdio.h>

HRESULT GetFolderDescriptionId(LPCWSTR pszPath, SHDESCRIPTIONID *pdid)
{
  HRESULT hr;
  LPITEMIDLIST pidl;
  if (SUCCEEDED(hr = SHParseDisplayName(pszPath, NULL,&pidl, 0, NULL))) {
    IShellFolder *psf;
    LPCITEMIDLIST pidlChild;
    if (SUCCEEDED(hr = SHBindToParent(pidl, IID_IShellFolder, (void**)&psf, &pidlChild))) {
      hr = SHGetDataFromIDList(psf, pidlChild,SHGDFIL_DESCRIPTIONID, pdid, sizeof(*pdid));
      psf->Release();
    }
    CoTaskMemFree(pidl);
  }
  return hr;
}

int __cdecl wmain(int argc, WCHAR **argv)
{
  SHDESCRIPTIONID did;
  if (SUCCEEDED(GetFolderDescriptionId(argv[1], &did)) && did.clsid == CLSID_RecycleBin) {
    printf("is a recycle binn");
  } else {
    printf("is not a recycle binn");
  }
  return 0;
}

C:> checkrecycle C:Windows
is not a recycle bin
C:> checkrecycle C:RECYCLERS-1-5-21-2127521184-1604012920-1887927527-72713
is a recycle bin