How to detect if a pointer was deleted and securely delete it?

Question

In C++ How to decide or know if a pointer was deleted before??

when i tried to delete a pointer that was previously deleted in another part of the c

Answer 1

use shared_ptr<> and shared_array<>, remember shared_ptr<> can be used to manage memory allocated to an array only if appropriate Deleter is provided, otherwise use shared_array<> to manage your arrays

A* a_tab=new A[100];
boost::shared_ptr a_tab_ok(a_tab,ArrayDeleter()); 

//only ok if

template 
    class ArrayDeleter
    {
    public:
        void operator () (T* d) const
        {
            delete [] d; //will delete array!
        }
    };

is provided