Vector of shared pointers , memory problems after clearing the vector

Question

I realized that after calling vector.clear() which hold shared pointers, the destructors of the object which own by shared_ptr is not being released. <

Answer 1

The problem arises when the push_back adds a copy of the shared_ptr to the vector, leaving the original dangling until main exists. If you don't make the shared_ptr in main scope, the problem does not happen. Just avoid making the shared_ptr in main scope. Make it as a temporary right in the push_back call.

Output is now:   

constructor
I am almost there
destructor
I am here

New code:

#include 
#include 
#include 

using namespace std;

class A
{
public:
  A(){cout << "constructor" << endl;};
  ~A(){cout << "destructor"  << endl;};
};

int main( )
{
  vector > test;
  test.push_back(shared_ptr(new A));
  cout << "I am almost there" << endl;
  test.clear();
  cout << "I am here" << endl;
  return 0;
}