dolfin team mailing list archive

[Johan Hake <johan.hake@xxxxxxxxx>]

On Tuesday February 1 2011 13:46:55 Anders Logg wrote:
> On Tue, Feb 01, 2011 at 01:36:59PM -0800, Johan Hake wrote:
> > On Tuesday February 1 2011 13:18:54 Anders Logg wrote:
> > > What is the correct way to check whether a shared_ptr is NULL?
> > 
> > What with:
> >  bool has_child() const
> >  {
> >  
> >    return _child.count()!=0;
> >  
> >  }
> 
> Will try that.
> 
> > or just or implement a constructor for Hierarchical which initialize the
> > shared_ptr to 0?
> 
> I was under the impression it's always initialized to 0, and
> initialization to zero should be handled by
> 
> _foo = shared_ptr<foo>();

Yes you seem to be correct.

From shared_ptr.hpp:

    shared_ptr(): px(0), pn() // never throws in 1.30+
    {
    }

where px is the pointer and pn the count (which is a shared objects in it 
self!)

Johan

> --
> Anders