delete by base class pointer?

[Gernot Frisch]

class Base{};
class Obj : public Base{};

std::vector<Base*> vpBase;
Obj o = new Obj();
vpBase.push_back(&o);

// Can I safely do this: ?
delete vpBase[0];

Thank you,

 

[Peter Koch Larsen]

class Base{};
class Obj : public Base{};

std::vector<Base*> vpBase;
Obj o = new Obj();
vpBase.push_back(&o);

// Can I safely do this: ?
delete vpBase[0];

Thank you,

No - undefined. But for most implementations this will turn out okay. Still
it is a silly example - there's not much going on here.

/Peter

 

[Karl Heinz Buchegger]

class Base{};
class Obj : public Base{};

std::vector<Base*> vpBase;
Obj o = new Obj();
vpBase.push_back(&o);

// Can I safely do this: ?
delete vpBase[0];

No. The destructor in the base class has
to be virtual.

class Base
{
public:
virtual ~Base() {}
};

Now you are safe.

 

[Gernot Frisch]

class Base{};
class Obj : public Base{};

std::vector<Base*> vpBase;
Obj o = new Obj();
vpBase.push_back(&o);

// Can I safely do this: ?
delete vpBase[0];

No. The destructor in the base class has
to be virtual.

class Base
{
public:
virtual ~Base() {}
};

Now you are safe.

Bingo. Now I completele understand 'virtual'. Thank you very much.