boost shared_ptr: difference between operator= and reset?

Question

Are there any differences between the two pieces of code below? Is any of them preferable to the other?

operator=

boost::shared_ptr&         


        

Answer 1

operator= takes another shared_ptr as a parameter thus creating another copy (and upping the reference count) while reset() takes a pointer and optionally a deleter, thus in reality creating a new shared_ptr on top of the current one.

reset is equivalent to (and probably implemented as)

void reset(T p, D d)
{
   shared_ptr shared(p,d);
   swap( shared );
}

operator= is likely to be implemented as:

shared_ptr& operator=( shared_ptr const& other )
{
   shared_ptr shared(other);
   swap(other);
   return *this;
}

The two functions are similar in that they release control of what they are already containing, if any, and manage a different pointer instead.