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- /* Copyright 2016-2017 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::function_collection */
- #include <boost/poly_collection/function_collection.hpp>
- #include <functional>
- #include <memory>
- #include <random>
- #include <vector>
- #include "rolegame.hpp"
- int main()
- {
- //[basic_function_1
- std::vector<std::unique_ptr<sprite>> sprs;
- std::vector<std::string> msgs;
- std::vector<window> wnds;
- //]
- // populate sprs
- std::mt19937 gen{92748}; // some arbitrary random seed
- std::discrete_distribution<> rnd{{1,1,1}};
- for(int i=0;i<4;++i){ // assign each type with 1/3 probability
- switch(rnd(gen)){
- case 0: sprs.push_back(std::make_unique<warrior>(i));;break;
- case 1: sprs.push_back(std::make_unique<juggernaut>(i));break;
- case 2: sprs.push_back(std::make_unique<goblin>(i));break;
- }
- }
- // populate msgs
- msgs.push_back("\"stamina: 10,000\"");
- msgs.push_back("\"game over\"");
- // populate wnds
- wnds.emplace_back("pop-up 1");
- wnds.emplace_back("pop-up 2");
- //[basic_function_2
- //= #include <boost/poly_collection/function_collection.hpp>
- //= ...
- //=
- // function signature accepting std::ostream& and returning nothing
- using render_callback=void(std::ostream&);
-
- boost::function_collection<render_callback> c;
- //]
- //[basic_function_3
- //<-
- auto render_sprite=[](const sprite& s){
- //->
- //= auto render_sprite(const sprite& s){
- return [&](std::ostream& os){s.render(os);};
- }/*<-*/;/*->*/
- //<-
- auto render_message=[](const std::string& m){
- //->
- //= auto render_message(const std::string& m){
- return [&](std::ostream& os){os<<m;};
- }/*<-*/;/*->*/
- //<-
- auto render_window=[](const window& w){
- //->
- //= auto render_window(const window& w){
- return [&](std::ostream& os){w.display(os);};
- }/*<-*/;/*->*/
- //= ...
- //=
- for(const auto& ps:sprs)c.insert(render_sprite(*ps));
- for(const auto& m:msgs)c.insert(render_message(m));
- for(const auto& w:wnds)c.insert(render_window(w));
- //]
- //[basic_function_4
- const char* comma="";
- for(const auto& cbk:c){
- std::cout<<comma;
- cbk(std::cout);
- comma=",";
- }
- std::cout<<"\n";
- //]
- //[basic_function_5
- auto cbk=*c.begin();
- cbk(std::cout); // renders first element to std::cout
- std::function<render_callback> f=cbk;
- f(std::cout); // exactly the same
- //]
- //[basic_function_6
- //= *c.begin()=render_message("last minute message"); // compile-time error
- //]
- }
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