Debug Assertion Failed while building SFML blueprint Asteroid game? - c++

Question

I was trying to follow the SFML Blueprint book. I managed to remove all the errors but one error remains in the code.
I have tried to find about the debug-assertion-failed.
I think this issue is arising due to the lists one of them is getting emptied.
My code for the world.cpp
#include "World.h"
#include "Entity.h"
World::World(int x, int y) : _x(x), _y(y) {}
World::~World() { clear(); }
void World::add(Entity* entity){
_entities_tmp.push_back(entity);
}
void World::clear()
{
for (Entity* entity : _entities)
delete entity;
_entities.clear();
for (Entity* entity : _entities_tmp)
delete entity;
_entities_tmp.clear();
_sounds.clear();
}
void World::add(Configuration::Sounds sound_id){
std::unique_ptr<sf::Sound> sound(new sf::Sound(Configuration::sounds.get(sound_id)));
sound->setAttenuation(0);
sound->play();
_sounds.emplace_back(std::move(sound));
}
bool World::isCollide(const Entity& other)
{
for (Entity* entity_ptr : _entities)
if (other.isCollide(*entity_ptr))
return true;
return false;
}
int World::size() {
return _entities.size() + _entities_tmp.size();
}
int World::getX() const{
return _x;
}
int World::getY() const{
return _y;
}
const std::list<Entity*> World::getEntities() const {
return _entities;
}
void World::update(sf::Time deltaTime)
{
if (_entities_tmp.size() > 0)
_entities.merge(_entities_tmp);
for (Entity* entity_ptr : _entities)
{
Entity& entity = *entity_ptr;
entity.update(deltaTime);
sf::Vector2f pos = entity.getPosition();
if (pos.x < 0)
{
pos.x = _x;
pos.y = _y - pos.y;
}
else if (pos.x > _x)
{
pos.x = 0;
pos.y = _y - pos.y;
}
if (pos.y < 0)
pos.y = _y;
else if (pos.y > _y)
pos.y = 0;
entity.setPosition(pos);
}
const auto end = _entities.end();
for (auto it_i = _entities.begin(); it_i != end; ++it_i)
{
Entity& entity_i = **it_i;
auto it_j = it_i;
it_j++;
for (; it_j != end; ++it_j)
{
Entity& entity_j = **it_j;
if (entity_i.isAlive() && entity_i.isCollide(entity_j))
entity_i.onDestroy();
if (entity_j.isAlive() && entity_j.isCollide(entity_i))
entity_j.onDestroy();
}
}
for (auto it = _entities.begin(); it != _entities.end();)
{
if (!(*it)->isAlive()){
delete *it;
it = _entities.erase(it);
}
else ++it;
}
_sounds.remove_if([](const std::unique_ptr<sf::Sound>& sound)->
bool {
return sound->getStatus() != sf::SoundSource::Status::Playing;
});
}
void World::draw(sf::RenderTarget& target, sf::RenderStates states) const
{
for (Entity* entity : _entities)
target.draw(*entity, states);
}
Code for world.hpp
#include <SFML/Graphics.hpp>
#include <SFML/Audio.hpp>
#include <list>
#include <memory>
#include "Configuration.h"
class Entity;
class World : public sf :: Drawable
{
public:
World(const World&) = delete;
World& operator=(const World&) = delete;
World(int x, int y);
~World();
void add(Entity* entity);
void clear();
bool isCollide(const Entity& other);
int size();
void add(Configuration::Sounds sound_id);
const std::list<Entity*> getEntities() const;
int getX() const;
int getY() const;
void update(sf::Time deltaTime);
private:
std::list<Entity*> _entities;
std::list<Entity*> _entities_tmp;
std::list<std::unique_ptr<sf::Sound>> _sounds;
virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;
const int _x;
const int _y;
};
code for Entity.h
class World;
class Entity : public sf::Drawable
{
public:
//Constructors
Entity(const Entity&) = delete;
Entity& operator= (const Entity&) = delete;
Entity(Configuration::Textures tex_id, World& world);
virtual ~Entity();
//Helpers
virtual bool isAlive() const;
const sf::Vector2f& getPosition() const;
template<typename ... Args>
void setPosition(Args&& ... args);
virtual bool isCollide(const Entity& other) const = 0;
//Updates
virtual void update(sf::Time deltaTime) = 0;
virtual void onDestroy();
protected:
friend class Meteor;
friend class Player;
friend class Saucer;
friend class ShootPlayer;
friend class ShootSaucer;
sf::Sprite _sprite;
sf::Vector2f _impulse;
World& _world;
bool _alive;
private:
virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const override;
};

Answer 1

if (_entities_tmp.size() > 0)
_entities.merge(_entities_tmp);
This does not work. merge works with two sorted ranges. And your vector is not sorted. This is why you get an assertion.
If not sorting them is on purpose and you just want to concatenate the two vectors, you can do:
_entities.reserve( _entities.size() + _entities_tmp.size() );
_entities.insert( _entities.end(), _entities_tmp.begin(), _entities_tmp.end() );