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// Copyright (c) 2018-2025 Jean-Louis Leroy
// Distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
#include <iostream>
#include <memory>
#include <string>
#include <boost/openmethod.hpp>
#include <boost/openmethod/initialize.hpp>
using boost::openmethod::virtual_ptr;
struct Character {
virtual ~Character() {
}
};
struct Warrior : Character {};
struct Device {
virtual ~Device() {
}
};
struct Hands : Device {};
struct Axe : Device {};
struct Banana : Device {};
struct Creature {
virtual ~Creature() {
}
};
struct Dragon : Creature {};
struct Bear : Creature {};
BOOST_OPENMETHOD_CLASSES(
Character, Warrior, Device, Hands, Axe, Banana, Creature, Dragon, Bear);
BOOST_OPENMETHOD(
fight, (virtual_ptr<Character>, virtual_ptr<Creature>, virtual_ptr<Device>),
std::string);
BOOST_OPENMETHOD_OVERRIDE(
fight, (virtual_ptr<Character>, virtual_ptr<Creature>, virtual_ptr<Banana>),
std::string) {
return "are you insane?";
}
BOOST_OPENMETHOD_OVERRIDE(
fight, (virtual_ptr<Character>, virtual_ptr<Creature>, virtual_ptr<Axe>),
std::string) {
return "not agile enough to wield";
}
BOOST_OPENMETHOD_OVERRIDE(
fight, (virtual_ptr<Warrior>, virtual_ptr<Creature>, virtual_ptr<Axe>),
std::string) {
return "and cuts it into pieces";
}
BOOST_OPENMETHOD_OVERRIDE(
fight, (virtual_ptr<Warrior>, virtual_ptr<Dragon>, virtual_ptr<Axe>),
std::string) {
return "and dies a honorable death";
}
BOOST_OPENMETHOD_OVERRIDE(
fight, (virtual_ptr<Character>, virtual_ptr<Dragon>, virtual_ptr<Hands>),
std::string) {
return "Congratulations! You have just vainquished a dragon with your bare "
"hands"
" (unbelievable, isn't it?)";
}
auto main() -> int {
boost::openmethod::initialize();
std::unique_ptr<Character> bob = std::make_unique<Character>(),
rambo = std::make_unique<Warrior>();
std::unique_ptr<Creature> elliott = std::make_unique<Dragon>(),
paddington = std::make_unique<Bear>();
std::unique_ptr<Device> hands = std::make_unique<Hands>(),
axe = std::make_unique<Axe>(),
chiquita = std::make_unique<Banana>();
std::cout << "bob fights elliot with axe:\n"
<< fight(*bob, *elliott, *axe) << "\n";
// bob fights elliot with axe:
// not agile enough to wield
std::cout << "rambo fights paddington with axe:\n"
<< fight(*rambo, *paddington, *axe) << "\n";
// rambo fights paddington with axe:
// and cuts it into pieces
std::cout << "rambo fights paddington with banana:\n"
<< fight(*rambo, *paddington, *chiquita) << "\n";
// rambo fights paddington with banana:
// are you insane?
std::cout << "rambo fights elliott with axe:\n"
<< fight(*rambo, *elliott, *axe) << "\n";
// rambo fights elliott with axe:
// and dies a honorable death
std::cout << "bob fights elliot with hands:\n"
<< fight(*bob, *elliott, *hands) << "\n";
// bob fights elliot with hands: Congratulations! You have just vainquished
// a dragon with your bare hands (unbelievable, isn't it?)
std::cout << "rambo fights elliot with hands:\n"
<< fight(*rambo, *elliott, *hands) << "\n";
// rambo fights elliot with hands:
// you just killed a dragon with your bare hands. Incredible isn't it?
return 0;
}
auto call_fight(Character& character, Creature& creature, Device& device) {
return fight(character, creature, device);
}
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