1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
/* Copyright 2024 Joaquin M Lopez Munoz.
* 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)
*
* See http://www.boost.org/libs/poly_collection for library home page.
*/
/* basic usage of boost::variant_collection */
#include <boost/poly_collection/variant_collection.hpp>
#include <random>
#include "rolegame.hpp"
template<typename... Ts>
struct overloaded:Ts...{using Ts::operator()...;};
template<class... Ts>
overloaded(Ts...)->overloaded<Ts...>;
int main()
{
//[basic_variant_1
//= #include <boost/poly_collection/variant_collection.hpp>
//= ...
//=
boost::variant_collection<
boost::mp11::mp_list<warrior,juggernaut,goblin,elf,std::string,window>
> c;
//]
{
//[basic_variant_2
boost::variant_collection_of<
warrior,juggernaut,goblin,elf,std::string,window
> c;
//]
}
// populate with sprites
std::mt19937 gen{92754}; // some arbitrary random seed
std::discrete_distribution<> rnd{{1,1,1,1}};
for(int i=0;i<5;++i){ // assign each type with 1/4 probability
switch(rnd(gen)){
case 0: c.insert(warrior{i});break;
case 1: c.insert(juggernaut{i});break;
case 2: c.insert(goblin{i});break;
case 3: c.insert(elf{i});break;
}
}
// populate with messages
c.insert(std::string{"\"stamina: 10,000\""});
c.insert(std::string{"\"game over\""});
// populate with windows
c.insert(window{"pop-up 1"});
c.insert(window{"pop-up 2"});
{
//[basic_variant_3
//= // usual utility to construct a visitor
//= template<typename... Ts>
//= struct overloaded:Ts...{using Ts::operator()...;};
//= template<class... Ts>
//= overloaded(Ts...)->overloaded<Ts...>;
const char* comma="";
for(const auto& r:c){
std::cout<<comma;
visit(overloaded{
[](const sprite& s) { s.render(std::cout); },
[](const std::string& str){ std::cout<<str; },
[](const window& w) { w.display(std::cout); }
},r);
comma=",";
}
std::cout<<"\n";
//]
}
{
//[basic_variant_4
auto print_sprite=[](const sprite& s) { s.render(std::cout); };
auto print_string=[](const std::string& str){ std::cout<<str; };
auto print_window=[](const window& w) { w.display(std::cout); };
const char* comma="";
for(const auto& r:c){
std::cout<<comma;
visit_by_index(
r,
print_sprite, // type #0: warrior
print_sprite, // type #1: juggernaut
print_sprite, // type #2: goblin
print_sprite, // type #3: elf
print_string, // type #4
print_window); // type #5
comma=",";
}
std::cout<<"\n";
//]
}
}
|
