Compilation problems with vector >

Question

Consider the following code:

#include 
#include 
#include 

using namespace std;

struct A
{
    int a;
    A(int         


        

Answer 1

Correct, std::auto_ptr cannot be used in std::vector.

What the compiler is complaining about there is the assignment operator for auto_ptr changes the object being assigned from, and so it cannot be const.

You want to use either boost::ptr_vector or a vector of boost::shared_ptrs

Answer 2

auto_ptr has a copy constructor with a non-const parameter, so the compiler can't call it from vector::push_back() since the latter has const parameter.

The reason is when you initialize one auto_ptr instance from another the new instance disconnects the object from the other instance and connects it to self so avoid a dangling pointer situation when one instance deletes the object and the other still holds a pointer to it.