Question

So given this simple scenario:

class A{
public:        
    A(){
        n = new int(10);
    }
    ~A(){
        delete n;
    }
    int* n;
};

int main(){
    A* a = new A();
}

Can this cause heap corruption (problems in general), since a-pointer hasn’t finished allocating, while I’m making a new allocation?

If so, using std::vector inside heap constructors in also prohibited, right?

Thank you.

Answer 1

Your a pointer has finished allocating.

New works as follows (oversimplified)

• Allocate
• Construct

So in your case

• Allocate A
• Construct A
  • Allocate int
  • Construct int – initialize
• Finish Construct A

This ignores cases involving exceptions..