shared-ptr.cpp

#include <iostream>
#include <memory>

using namespace std;

class Renderer
{
    public:
       int xyz = 99;
    
        Renderer() {
            cout<<"xyz const: " << xyz << endl;
        }
};

class Context
{
public:
    std::shared_ptr<Renderer> renderer;
    std::size_t targetFrameDuration;

    Context() : renderer(nullptr), targetFrameDuration(0) {}

    ~Context() {
        std::cout << "Context was destroyed" << std::endl;
    }
};

auto context = std::make_shared<Context>();

void createRenderer(const std::shared_ptr<Renderer> & renderer)
{
    cout<<"create renderer 1" << endl;
    renderer->xyz = 98;
    context->renderer = renderer;
    cout<<"xyz 1: " << renderer->xyz << endl;
    cout<<"create renderer 2" << endl;
}


int main()
{
    auto renderer = std::make_shared<Renderer>();
    renderer->xyz = 97;
    cout<<"xyz 2: " << renderer->xyz << endl;
    
    createRenderer(renderer);
    
    cout<<"xyz final: " << context->renderer->xyz << endl;
    cout<<"Hello World" << endl;

    return 0;
}