[2433] introduced dns_fwd.h, a set of forward declarations for libdns++.

totally independent from the subject of the task, but we'll need this
type of thing sooner or later (and sooner is better).

src/lib/dns/dns_fwd.h

@@ -0,0 +1,64 @@
+// Copyright (C) 2012  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#ifndef DNS_FWD_H
+#define DNS_FWD_H 1
+
+/// \file dns_fwd.h
+/// \brief Forward declarations for definitions of libdns++
+///
+/// This file provides a set of forward declarations for definitions commonly
+/// used in libdns++ to help minimize dependency when actual the definition
+/// is not necessary.
+
+namespace isc {
+namespace dns {
+
+class EDNS;
+class Name;
+class MasterLoader;
+class MasterLoaderCallbacks;
+class Message;
+class AbstractMessageRenderer;
+class MessageRenderer;
+class NSEC3Hash;
+class NSEC3HashCreator;
+class Opcode;
+class Question;
+class Rcode;
+namespace rdata {
+class Rdata;
+}
+class RRCollator;
+class RRClass;
+class RRType;
+class RRTTL;
+class AbstractRRset;
+class RdataIterator;
+class RRsetCollectionBase;
+class RRsetCollection;
+class Serial;
+class TSIGContext;
+class TSIGError;
+class TSIGKey;
+class TSIGKeyRing;
+class TSIGRecord;
+
+} // namespace dns
+} // namespace isc
+#endif  // DNS_FWD_H
+
+// Local Variables:
+// mode: c++
+// End: