Re: [libxml++] NodeList problem.

[Jonathan Wakely <cow compsoc man ac uk>]

On Thu, Jun 09, 2005 at 01:53:03PM -0300, Darko Miletic wrote:

> Jonathan Wakely wrote:
> 
> >Surely not?!?!
> >
> >If the container is empty calling begin() will return an iterator that
> >compares equal to end().  _dereferencing_ that iterator would be an
> >error, but not simply copying it.
> 
> It will be error if you use (as you did) reference to NodeList. You 
> wrote the code like this:
> 
> const xmlpp::Node::NodeList& m_nodeList = root->get_children();
> 
> that means that you take reference to the temporary created nodelist 
> object. It is invalid after that line is executed an hence the access 

Not true, the standard requires that a temporary object bound to a const
reference is kept in scope as long as the reference.

> violation. Therefore you need to copy it. Instead of const 
> xmlpp::Node::NodeList& use just xmlpp::Node::NodeList that way the list 
> will be copied as it should because the declaration of 
> xmlpp::Node::get_children is like this:
> 
> NodeList get_children(const std::string& name = std::string());
> 
> So no reference is returned here.
> 
> The code should be like this:
> 
> xmlpp::Node::NodeList m_nodeList = root->get_children();
> xmlpp::Node::NodeList::const_iterator itr = m_nodeList.begin();

Not true, the original code should work AFAICT.

jon

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