wxFileModificationTime() needs wxDateTime, put it inside wxUSE_DATETIME

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@40394 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/filefn.h

@@ -545,9 +545,13 @@ WXDLLIMPEXP_BASE bool wxFindFileInPath(wxString *pStr, const wxChar *pszPath, co
 // On non-Windows platform, probably just return the empty string.
 WXDLLIMPEXP_BASE wxString wxGetOSDirectory();
 
+#if wxUSE_DATETIME
+
 // Get file modification time
 WXDLLIMPEXP_BASE time_t wxFileModificationTime(const wxString& filename);
 
+#endif // wxUSE_DATETIME
+
 // Parses the wildCard, returning the number of filters.
 // Returns 0 if none or if there's a problem,
 // The arrays will contain an equal number of items found before the error.