CODEWITHSUNDEEP
c++
hft654
hft654

Reputation: 51

Why only static member can access private destructor?

#include <iostream>
using namespace std;

class MonsterDB
{
private:
    ~MonsterDB() {}; //private destructor
public:
    static void DestroyInstance(MonsterDB* pInstance)
    {
        //static member can access private destructor
        delete pInstance;
    }
    //...other methods
};
int main()
{
    // instantiation in heap
    MonsterDB* pMyDatabase = new MonsterDB();

    MonsterDB::DestroyInstance(pMyDatabase);
    
    return 0;
}

guys , why only static member can access private destructor?

When i remove static from this :

static void DestroyInstance(MonsterDB* pInstance)

i get an error!

The reason i asked the question is that :

#include <iostream>
using namespace std;

class MonsterDB
{
private:
    int variable;

    
    
public:
    void printer()
    {
        cout<<variable<<endl;
    }
    void instancer(int s)
    {
        variable = s;
    }
    
    //...other methods
};

int main()
{
    MonsterDB obj1;
    int var = 5;
    obj1.instancer(var);
    obj1.printer();
}

In the above code I made, both functions : printer and instancer accessed private variable without having to specify static keyword in those functions.

Sorry for your time, advance thanks! hoping to give real intuition behind this.

Upvotes: 0

Views: 70

Answers (1)

IWonderWhatThisAPIDoes
IWonderWhatThisAPIDoes

Reputation: 1048

As you might recall, static (in this context) means that the function behaves like a global function, meaning it is not bound to a single instance of the class.

MonsterDB::DestroyInstance(pMyDatabase);

Obviously, if DestroyInstance is not static, this line will always fail (and it has nothing to do with private destructors). Calling it like this

pMyDatabase->DestroyInstance(pMyDatabase);

will work even if the method is not static (although it is very awkward, it makes more sense to make this method static).

Upvotes: 1

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