Class destructor c++

Question

I've got a question about destructors in c++.

I've got a class like this :

class X {  

private:
    string m_instanceName
    string m_path;
    ConnexionHashMap m_connexions;
    Module** m_moduleType;
    Powerdomain* m_powerDomain;
    Module ** m_father;
};

Here are some information concerning ConnexionHashMap :

typedef hash_map<const string, Connexion, strptrhash, strptrequal> ConnexionHashMap;

struct Net{
     string name;
     vector<string> connectedPins;
     bool isPin;
};

typedef struct Net Net;

struct Connexion{
    string pin;
    Net* net;
};

typedef struct Connexion Connexion;

If I don't want to delete the m_modulType the m_powerDomain and m_father (because they are likely to be referred to by another object), do I have to explicitely write a destructor method ?

I know that string is a standard object and will be destroy by its own destructor, but will the ConnexionHashMap be destroyed by the standard hashmap template destructor or should i delete it manually somehow ?

(also on a sidenote is there an easy way to see how my memory is managed while my program is running on Eclipse cdt ? )

Quite unrelated comment: In C++ you don't need to explicitly typedef a struct to use it without the struct keyword. A struct is just like a class (but with members declared as public by default). — Christian Rau
Do CDT have a console interface to GDB? If so you can always issue the command x, for example x myptr or x/64xb (show 64 bytes as hexadecimals.) For reference sourceware.org/gdb/current/onlinedocs/gdb/… — Skurmedel

sergio sergio · Accepted Answer · 2011-05-25T14:38:05

If I don't want to delete the m_modulType the m_powerDomain and m_father (because they are likely to be referred to by another object, do I have to explicitely write a destructor method?

m_powerDomain, m_father, and m_modulType are pointers and the objects they point to will not be deleted unless you do so explicitly. So, you should write a destructor if you want them to be deleted, otherwise they need not.

I know that string is a standard object and will be destroy by its own destructor, but will the ConnexionHashMap be destroyed by the standard hashmap template destructor or should i delete it manually somehow ?

It is not that std::string are standard object that will make them deleted automatically, but the fact that you are including a std::string in your class as a member, so the string is physically allocated inside of your object memory and when this one is deleted the former is also (without need of specifying anything in the destructor).

All the same, m_connexions, which is included as an object member, not pointer, will be automatically deleted by the destructor, no need to do anything.

(also on a sidenote is there an easy way to see how my memory is managed while my program is running on Eclipse cdt ? )

you can use a profiler like valgrind or any other you find available...

Class destructor c++

5 Answers