/indra/test/lldoubledispatch_tut.cpp
https://bitbucket.org/lindenlab/viewer-beta/ · C++ · 239 lines · 143 code · 27 blank · 69 comment · 0 complexity · 6c869bd1c0d0ce72089590d657239eb2 MD5 · raw file
- /**
- * @file lldoubledispatch_tut.cpp
- * @author Nat Goodspeed
- * @date 2008-11-13
- * @brief Test for lldoubledispatch.h
- *
- * This program tests the DoubleDispatch class, using a variation on the example
- * from Scott Meyers' "More Effective C++", Item 31.
- *
- * $LicenseInfo:firstyear=2008&license=viewerlgpl$
- * Second Life Viewer Source Code
- * Copyright (C) 2010, Linden Research, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License only.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
- * $/LicenseInfo$
- */
- // Precompiled header
- #include "linden_common.h"
- // associated header
- #include "lldoubledispatch.h"
- // STL headers
- // std headers
- #include <string>
- #include <iostream>
- #include <typeinfo>
- // external library headers
- // other Linden headers
- #include "lltut.h"
- /*---------------------------- Class hierarchy -----------------------------*/
- // All objects are GameObjects.
- class GameObject
- {
- public:
- GameObject(const std::string& name): mName(name) {}
- virtual ~GameObject() {}
- virtual std::string stringize() { return std::string(typeid(*this).name()) + " " + mName; }
- protected:
- std::string mName;
- };
- // SpaceStation, Asteroid and SpaceShip are peer GameObjects.
- struct SpaceStation: public GameObject
- {
- SpaceStation(const std::string& name): GameObject(name) {}
- // Only a dummy SpaceStation is constructed without a name
- SpaceStation(): GameObject("dummy") {}
- };
- struct Asteroid: public GameObject
- {
- Asteroid(const std::string& name): GameObject(name) {}
- Asteroid(): GameObject("dummy") {}
- };
- struct SpaceShip: public GameObject
- {
- SpaceShip(const std::string& name): GameObject(name) {}
- SpaceShip(): GameObject("dummy") {}
- };
- // SpaceShip is specialized further into CommercialShip and MilitaryShip.
- struct CommercialShip: public SpaceShip
- {
- CommercialShip(const std::string& name): SpaceShip(name) {}
- CommercialShip(): SpaceShip("dummy") {}
- };
- struct MilitaryShip: public SpaceShip
- {
- MilitaryShip(const std::string& name): SpaceShip(name) {}
- MilitaryShip(): SpaceShip("dummy") {}
- };
- /*-------------------------- Collision functions ---------------------------*/
- // This mechanism permits us to overcome a limitation of Meyers' approach: we
- // can declare the parameter types exactly as we want, rather than having to
- // make them all GameObject& parameters.
- std::string shipAsteroid(SpaceShip& ship, Asteroid& rock)
- {
- // std::cout << rock.stringize() << " has pulverized " << ship.stringize() << std::endl;
- return "shipAsteroid";
- }
- std::string militaryShipAsteroid(MilitaryShip& ship, Asteroid& rock)
- {
- // std::cout << rock.stringize() << " has severely damaged " << ship.stringize() << std::endl;
- return "militaryShipAsteroid";
- }
- std::string shipStation(SpaceShip& ship, SpaceStation& dock)
- {
- // std::cout << ship.stringize() << " has docked at " << dock.stringize() << std::endl;
- return "shipStation";
- }
- std::string asteroidStation(Asteroid& rock, SpaceStation& dock)
- {
- // std::cout << rock.stringize() << " has damaged " << dock.stringize() << std::endl;
- return "asteroidStation";
- }
- /*------------------------------- Test code --------------------------------*/
- namespace tut
- {
- struct dispatch_data
- {
- dispatch_data():
- home(new SpaceStation("Terra Station")),
- obstacle(new Asteroid("Ganymede")),
- tug(new CommercialShip("Pilotfish")),
- patrol(new MilitaryShip("Enterprise"))
- {}
- // Instantiate and populate the DoubleDispatch object.
- typedef LLDoubleDispatch<std::string, GameObject> DD;
- DD dispatcher;
- // Instantiate a few GameObjects. Make sure we refer to them
- // polymorphically, and don't let them leak.
- std::auto_ptr<GameObject> home;
- std::auto_ptr<GameObject> obstacle;
- std::auto_ptr<GameObject> tug;
- std::auto_ptr<GameObject> patrol;
- // prototype objects
- Asteroid dummyAsteroid;
- SpaceShip dummyShip;
- MilitaryShip dummyMilitary;
- CommercialShip dummyCommercial;
- SpaceStation dummyStation;
- };
- typedef test_group<dispatch_data> dispatch_group;
- typedef dispatch_group::object dispatch_object;
- tut::dispatch_group ddgr("double dispatch");
- template<> template<>
- void dispatch_object::test<1>()
- {
- // Describe param types using explicit DD::Type objects
- // (order-sensitive add() variant)
- dispatcher.add(DD::Type<SpaceShip>(), DD::Type<Asteroid>(), shipAsteroid, true);
- // naive adding, won't work
- dispatcher.add(DD::Type<MilitaryShip>(), DD::Type<Asteroid>(), militaryShipAsteroid, true);
- dispatcher.add(DD::Type<SpaceShip>(), DD::Type<SpaceStation>(), shipStation, true);
- dispatcher.add(DD::Type<Asteroid>(), DD::Type<SpaceStation>(), asteroidStation, true);
- // Try colliding them.
- ensure_equals(dispatcher(*home, *tug), // reverse params, SpaceShip subclass
- "shipStation");
- ensure_equals(dispatcher(*patrol, *home), // forward params, SpaceShip subclass
- "shipStation");
- ensure_equals(dispatcher(*obstacle, *home), // forward params
- "asteroidStation");
- ensure_equals(dispatcher(*home, *obstacle), // reverse params
- "asteroidStation");
- ensure_equals(dispatcher(*tug, *obstacle), // forward params, SpaceShip subclass
- "shipAsteroid");
- ensure_equals(dispatcher(*obstacle, *patrol), // reverse params, SpaceShip subclass
- // won't use militaryShipAsteroid() because it was added
- // in wrong order
- "shipAsteroid");
- }
- template<> template<>
- void dispatch_object::test<2>()
- {
- // Describe param types using explicit DD::Type objects
- // (order-sensitive add() variant)
- // adding in correct order
- dispatcher.add(DD::Type<MilitaryShip>(), DD::Type<Asteroid>(), militaryShipAsteroid, true);
- dispatcher.add(DD::Type<SpaceShip>(), DD::Type<Asteroid>(), shipAsteroid, true);
- dispatcher.add(DD::Type<SpaceShip>(), DD::Type<SpaceStation>(), shipStation, true);
- dispatcher.add(DD::Type<Asteroid>(), DD::Type<SpaceStation>(), asteroidStation, true);
-
- ensure_equals(dispatcher(*patrol, *obstacle), "militaryShipAsteroid");
- ensure_equals(dispatcher(*tug, *obstacle), "shipAsteroid");
- }
- template<> template<>
- void dispatch_object::test<3>()
- {
- // Describe param types with actual prototype instances
- // (order-insensitive add() variant)
- dispatcher.add(dummyMilitary, dummyAsteroid, militaryShipAsteroid);
- dispatcher.add(dummyShip, dummyAsteroid, shipAsteroid);
- dispatcher.add(dummyShip, dummyStation, shipStation);
- dispatcher.add(dummyAsteroid, dummyStation, asteroidStation);
- ensure_equals(dispatcher(*patrol, *obstacle), "militaryShipAsteroid");
- ensure_equals(dispatcher(*tug, *obstacle), "shipAsteroid");
- ensure_equals(dispatcher(*obstacle, *patrol), "");
- }
- template<> template<>
- void dispatch_object::test<4>()
- {
- // Describe param types with actual prototype instances
- // (order-insensitive add() variant)
- dispatcher.add(dummyShip, dummyAsteroid, shipAsteroid);
- // Even if we add the militaryShipAsteroid in the wrong order, it
- // should still work.
- dispatcher.add(dummyMilitary, dummyAsteroid, militaryShipAsteroid);
- dispatcher.add(dummyShip, dummyStation, shipStation);
- dispatcher.add(dummyAsteroid, dummyStation, asteroidStation);
- ensure_equals(dispatcher(*patrol, *obstacle), "militaryShipAsteroid");
- ensure_equals(dispatcher(*tug, *obstacle), "shipAsteroid");
- }
- template<> template<>
- void dispatch_object::test<5>()
- {
- dispatcher.add<SpaceShip, Asteroid>(shipAsteroid);
- dispatcher.add<MilitaryShip, Asteroid>(militaryShipAsteroid);
- dispatcher.add<SpaceShip, SpaceStation>(shipStation);
- dispatcher.add<Asteroid, SpaceStation>(asteroidStation);
- ensure_equals(dispatcher(*patrol, *obstacle), "militaryShipAsteroid");
- ensure_equals(dispatcher(*tug, *obstacle), "shipAsteroid");
- }
- } // namespace tut