'Free heap modifed' after deleting custom class containing Sprite

cocos2d-x C++
1

I’m using Cocos2d-x 3.16 on VS2013.

I made a custom class with sprites in it,
which looks like this

struct Weapon
{
private:
public:
 Weapon();
 ~Weapon();
 Sprite *base, *barrel, *muzzleFlash;
 Sprite *lasMuzzle, *lasBody, *lasImpact;
 //other variables (int, float)
};

class Drone
{
private:
 Node* scene;
 Sprite *Chassis, *Turret, *Shield, *boostAnim;
 cocos2d::MotionStreak* MS;
 std::vector<Weapon*> Weapons; //struct defined above
 //variables and functions below
public:
 ...
 //variables and functions below
};

After deleting drone object, error occurs.

HEAP: Free Heap block XXXXXXXX modified at XXXXXXXX after it was freed

and when I try on the android device, this error occurs.

fatal signal 11 (sigsegv) code 2, fault addr (address)

destructors of Weapon and Drone,

Weapon::~Weapon()
{
 if (muzzleFlash != nullptr)
 {
  muzzleFlash->removeFromParentAndCleanup(true);
 }
 if (barrel != nullptr)
 {
  barrel->removeFromParentAndCleanup(true);
 }
 if (lasMuzzle != nullptr)
 {
  lasMuzzle->removeFromParentAndCleanup(true);
 }
 if (lasBody != nullptr)
 {
  lasBody->removeFromParentAndCleanup(true);
 }
 if (lasImpact != nullptr)
 {
  lasImpact->removeFromParentAndCleanup(true);
 }
 if (base != nullptr)
 {
  base->removeFromParentAndCleanup(true);
 }
}

Drone::~Drone()
{
 for (int loop = 0; loop < Weapons.size(); loop++)
 {
  delete Weapons[loop];
 }
 Weapons.clear();

 if (Shield != nullptr)
 {
  Shield->removeAllChildrenWithCleanup(true);
  Shield->removeFromParentAndCleanup(true);
 }
 if (boostAnim != nullptr)
 {
  boostAnim->removeAllChildrenWithCleanup(true);
  boostAnim->removeFromParentAndCleanup(true);
 }
 if (Turret != nullptr)
 {
  Turret->removeAllChildrenWithCleanup(true);
  Turret->removeFromParentAndCleanup(true);
 }
 if (MS != nullptr)
 {
  MS->removeFromParentAndCleanup(true);
 }
 if (Chassis != nullptr)
 {
  Chassis->removeAllChildrenWithCleanup(true);
  Chassis->removeFromParentAndCleanup(true);
 }
}

I stored objects in std::list, delete like,

for (auto loop = vRobots.begin(); loop != vRobots.end();)
{
	auto bot = *loop;
	if (bot->isDestroyed)
	{
		vRobots.erase(loop++);
		if (bot == EnemyBot)
		{
			endBattle(true);
			return;
		}
		delete bot;
	}
	else
	++loop;
}

Strange thing is, there is Projectile class which is also a custom class,
and deleting projectiles object doesn’t cause problem.

Projectile::~Projectile()
{
	delete fHit; //Factory Function. nothing special.
	image->removeFromParentAndCleanup(true); //the only sprite in the class.
	//CCLOG("Projectile Destruct");
}

Maybe it’s not a good idea to make a class like these?
or maybe I’m blind and missed something? There aren’t any other codes than those really.
I have no idea.

2

Why Weapon is a struct but not a class? In cocos2d-x, always construct game objects inherited from cocos2d::Ref so their retain counts could be easily maintained by the underlying autorelease mechanism:

class Weapon : cocos2d::Ref
class Drone : cocos2d::Ref

Hence containers of cocos2d::Ref objects should be cocos2d::Vector here:

cocos2d::Vector<Weapon*> Weapons;

In such manner you don’t need to clear the list of weapons in the destructor

For those Sprite*, MotionStreak*, or any objects that are inheriting from cocos2d::Node, do not retain or remove them manually as the best practice, and let their parent nodes as the only object to manage their retain counts; on destruction of the root scene, the leaf nodes would be subsequently destructed along the tree of the scene graph.

3

But Drone class doesn’t inherit Ref either.
Drone Class merely has Sprites in them.
Well, yes I should change that struct to class anyway.

4

I mean both Drone and Weapon should be inherited from Ref

5

I followed this one to make my own custom class. Is this not a good practice?

6

He is just throwing out some pseudo codes so that’s not a sample you should follow.

7

I made my classes inherit Node,
didn’t solve anything.
still same heap error, during CCRenderer