Re: std::list::begin() returns const_iterator?

From:
Ulrich Eckhardt <eckhardt@satorlaser.com>
Newsgroups:
comp.lang.c++.moderated
Date:
Fri, 12 Oct 2007 11:46:21 CST
Message-ID:
<pep3u4-e62.ln1@satorlaser.homedns.org>
Sven wrote:

        typedef helper::USmartPtr<Item> ItemPtr;
        typedef std::list<ItemPtr> ItemList;
        ItemList m_items; //!< list of items in this source

  ...

        for ( ItemList::iterator it( this->m_items.begin() );
                it != this->m_items.end(); ++it ) {
                ...
        }


[...]

Using ItemList::const_iterator works here.


My guess is that you are in a const memberfunction. Inside that function,
only the const overload of list<>::begin() is available, which consequently
also returns a const_iterator.

I would interpret the error message in that way, that the begin()
methods returns something like a const_iterator which cannot be used
in the constructor for a iterator.
But if this is correct, how can I initialize the ItemList::iterator ?


A const memberfunction promises not to change the members. Since the list is
a member, it and its elements are treated as constants, too.

Uli

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