c++ - should destructior be declared/implemented in pointerless class?

Question

Should destructior be declared/implemented in pointerless class? Is there any advantage of having/not having it ?

What I men is:

class Point
{
public: 
    int X, Y;
    Point(int x, int y);
    //~Point(void);       //should I uncoment it and implement empty destructor ?
}

must read: http://www.parashift.com/c++-faq/dtors.html – abnvp Jan 08 '13 at 15:24 — abnvp, Jan 08 '13 at 15:24

score 5 · Accepted Answer · edited May 23 '17 at 12:04

Should destructior be declared/implemented in pointerless class?

No need^{[conditions apply]}. the compiler will generate one for you.
You should provide one only if you want to perform something specific, which the compiler will not.
For example:

Resource management(Memory managemnt, FIle handling),
Logging,
Close network connections,
In short custom functionality which needs to execute each time a object is destroyed

In general the thumb rule is:
"If you need to provide a copy constructor or a copy assignment operator then you most probably also need to provide your own destructor."
Popularly, this rule is known as the Rule of Three.

^{[conditions apply]} If your class is meant to act as an Base class for Inheritance and your implementation will require calling delete on a Base class pointer pointing to a derived class object then you need to provide a destructor and mark it as virtual in Base class, failure to do so will result in Undefined Behavior.

Is there any advantage of having/not having it?

None, since the compiler does the same there is no need to do the extra typing.

... or if you want the destructor to be virtual. But `Point` would not make a good base class. — aschepler, Jan 08 '13 at 15:03
@aschepler: You caught me in an edit.Added more detail to make it absolutely clear.Hth. — Alok Save, Jan 08 '13 at 15:30

score 2 · Answer 2 · answered Jan 08 '13 at 14:57

No, you shouldn't have a non-virtual destructor if you're not managing resources.

If you expect to derive from the class and plan on polymorphic deletion (i.e. delete a derived object through a base class pointer), you need a virtual destructor.

In fact, you shouldn't be managing resources directly, but have wrappers - i.e. smart pointers instead of raw pointers & manual allocation/deallocation.

c++ - should destructior be declared/implemented in pointerless class?

2 Answers2