CODEWITHSUNDEEP
c++auto-ptr
FireAphis
FireAphis

Reputation: 6790

Returning multiple auto_ptrs from a function

I have a function that allocates two variables on the heap and returns them to the caller. Something like this:

void Create1(Obj** obj1, Obj** obj2)
{
    *obj1 = new Obj;
    *obj2 = new Obj;
}

Usually, in similar cases, when I have a function with one variable I use the "source" trick with auto_ptr:

auto_ptr<Obj> Create2()
{
    return new Obj;
}

I would like to rewrite Create1 using auto_ptr but not sure how to do it. As far as I understand I cannot return auto_ptr by reference, am I right? So is it possible at all?

Upvotes: 2

Views: 699

Answers (2)

Timbo
Timbo

Reputation: 28050

You can assign to a std::auto_ptr by calling its reset method:

void f( std::auto_ptr<Obj>& pObj1, std::auto_ptr<Obj>& pObj2 )
{
    pObj1.reset( new Obj );
    pObj2.reset( new Obj );
}

The reset call will properly delete whatever the auto_ptr was pointing to before.

Upvotes: 4

Fred Larson
Fred Larson

Reputation: 62053

Related question: Returning multiple values from a C++ function

I wouldn't expect problems using auto_ptr in a pair or tuple. Returning a struct containing a couple of auto_ptr members should work too.

Upvotes: 4

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