How do virtual destructors work?
bounds-checker, c++, destructor, visual-c++
Solution
Deleting a derived-class object through a base-class pointer when the base class does not have a virtual destructor leads to undefined behavior.
What you've observed (that the derived-class portion of the object never gets destroyed and therefore its members never get deallocated) is probably the most common of many possible behaviors, and a good example of why it's important to make sure your destructors are virtual when you use polymorphism this way.
Problem
Few hours back I was fiddling with a Memory Leak issue and it turned out that I really got some basic stuff about virtual destructors wrong! Let me put explain my class design. ``` class Base { virtual push_elements() {} }; class Derived:public Base { vector<int> x; public: void push_elements(){ for(int i=0;i <5;i++) x.push_back(i); } }; void main() { Base* b = new Derived(); b->push_elements(); delete b; } ``` The bounds checker tool reported a memory leak in the derived class vector. And I figured out that the destructor is not virtual and the derived class destructor is not called. And it surprisingly got fixed when I made the destructor virtual. Isn't the vector deallocated automatically even if the derived class destructor is not called? Is that a quirk in BoundsChecker tool or is my understanding of virtual destructor wrong?