gistfile1.cpp

#include <iostream>
#include <string>
#include <vector>

#include <entityx/entityx.h>

struct TestComponent : entityx::Component<TestComponent> {
    explicit TestComponent(std::string _name = "test") {
        name = _name;
    }
    std::string name;
};

struct TestSystem : public entityx::System<TestSystem> {
    void update(entityx::ptr<entityx::EntityManager> es, entityx::ptr<entityx::EventManager> events, double dt) override {

        entityx::EntityManager::View entities = es->entities_with_components<TestComponent>();
        entityx::ptr<TestComponent> test;
        for (auto entity : entities) {
            // entityx::ptr<TestComponent> test = entity.component<TestComponent>();
            entity.unpack<TestComponent>(test);
            if (test) { //null test
                std::cout << "test: " << test->name << "\n";
            }
        }
        std::cout << "=====================\n";
    }
};

class GameManager : public entityx::Manager {
public:

    void configure() {
        system_manager->add<TestSystem>();
    }

    void initialize() {
        //create any starting entities here.

        //create a test entity.
        entityx::Entity testEntity1 = entity_manager->create();
        
        //create a component, and assign it to this entity
        entityx::ptr<TestComponent> testComponent1 = testEntity1.assign<TestComponent>("test component from assign");
        
        //create a test entity using syntax as given in EntityX README
        entityx::Entity testEntity2 = entity_manager->create();
        
        entityx::ptr<TestComponent> testComponent2 = new TestComponent("test component from new");
        //ERROR GIVEN BY ABOVE LINE: No viable conversion from 'TestComponent *' to 'entityx::ptr<TestComponent>' (aka 'std::__1::shared_ptr<TestComponent>')
        testEntity2.assign(testComponent2);
       
    }

    void update(double dt) {
        //call all the subsystems here, in order.
        system_manager->update<TestSystem>(dt);
    }
};

int main(int argc, const char * argv[])
{
    GameManager* game = new GameManager();
    game->start();

    // insert code here...
    std::cout << "Hello, World!\n";

    float loop_time_s = 1;
    while(true) {

        sleep(loop_time_s);
        game->update(loop_time_s);

        std::cout << "looped.\n";

    }
    
    game->stop();

    return 0;
}

//Current output shows no entities printed:
//GOT:
/*
Hello, World!
=====================
looped.
=====================
looped.
=====================
looped.
*/

//EXPECTED:
/*
Hello, World!
test: test entity from initialize.
test: test entity from main.
=====================
looped.
test: test entity from initialize.
test: test entity from main.
=====================
looped.
test: test entity from initialize.
test: test entity from main.
=====================
looped.
*/