Question

Here’s my code:

#include <vector>
#include <stdio.h>
#include <iostream>

using namespace std;

class Foo 
{
public:
    Foo()
    {
    }
    ~Foo()
    {
    }
    void Bar()
    {
        cout << "bar" << endl;
    }
};

template <class T>
void deleteVectorOfPointers( T * inVectorOfPointers )
{
    typename T::iterator i;
    for ( i = inVectorOfPointers->begin() ; i < inVectorOfPointers->end(); i++ )
    {
        delete * i;
    }
    delete inVectorOfPointers;
}

int main()
{
    //create pointer to a vector of pointers to foo
    vector<Foo*>* pMyVec = new vector<Foo*>();
    //create a pointer to foo
    Foo* pMyFoo = new Foo();
    //add new foo pointer to pMyVec
    pMyVec->push_back(pMyFoo);
    //call Bar on 0th Foo element of pMyVec
    pMyVec->at(0)->Bar();
    //attempt to delete the pointers inside the vector and the vector itself
    deleteVectorOfPointers(pMyVec);
    //call Bar on 0th Foo element of pMyVec
    pMyVec->at(0)->Bar();
    //call Bar directly from the pointer created in this scope
    pMyFoo->Bar();
    return 0;
}

I am trying to delete a pointer to a vector as well as all the pointers inside of the vector. However, Bar is still executing just fine after I try to do this…

Answer 1

It causes undefined-behavior. It means that anything can happen. This:

*reinterpret_cast<int*>(0x12345678) = 314159;

may also work… So what?