DeleteLater works... but why?

[TheGrimace]

Would I get the same same result if the instance of A&C were inside of B?

IE

A&C -> signals -> B

B -> signals -> D (the object that created B) to delete it.

but A and C are new instances of those classes created in B.

kind of like:

class A : public QObject{ 
      //...
      signals:
        void sigA(QObject *);};
class B : public QObject{
      //...
      B() { a= new A();  b=new B();  connect(AtoB);  connect(CtoB);}
      signals:
        void sigB(int);
      public slots:
        void slotB(QObject *o){  emit sigB(m_list.indexOf(o)); }
      };
class C : public QObject {
      //...
      public slots:
        void slotC(QObject *o){...}
      };
class D : public QObject {
       //...
       public:
       D() {  b = new B(); connect(B to D);}
       public slots:
       DSlot() { delete b or deletelater b}
       };

class A : public QObject{ 
      //...
      signals:
        void sigA(QObject *);};
class B : public QObject{
      //...
      B() { a= new A();  b=new B();  connect(AtoB);  connect(CtoB);}
      signals:
        void sigB(int);
      public slots:
        void slotB(QObject *o){  emit sigB(m_list.indexOf(o)); }
      };
class C : public QObject {
      //...
      public slots:
        void slotC(QObject *o){...}
      };
class D : public QObject {
       //...
       public:
       D() {  b = new B(); connect(B to D);}
       public slots:
       DSlot() { delete b or deletelater b}
       };

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and B initiates a call to the D Slot which deletes it and its children.

[wysota]

The relationship doesn't matter. The only thing that matters is that more than one slot operates on the same object that gets deleted in one of the slots. If that is the case, you have to use deleteLater() or somehow check if the pointer is stil valid (checking for null won't do).

[TheGrimace]

That is most likely what was going wrong then.

Thank You for your help.