[Boost-bugs] [Boost C++ Libraries] #5888: [Documentation] iterator_facade docs -- const correctness problem.

Subject: [Boost-bugs] [Boost C++ Libraries] #5888: [Documentation] iterator_facade docs -- const correctness problem.
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-09-10 19:10:50

#5888: [Documentation] iterator_facade docs -- const correctness problem.
----------------------------------------------+-----------------------------
 Reporter:  Frank Erens <seysayux@…>          |       Owner:  dave    
     Type:  Bugs                              |      Status:  new     
Milestone:  To Be Determined                  |   Component:  iterator
  Version:  Boost 1.47.0                      |    Severity:  Cosmetic
 Keywords:                                    |  
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 On this documentation page, second box:
 http://www.boost.org/doc/libs/1_47_0/libs/iterator/doc/iterator_facade.html#a

 -constant-node-iterator there is a problem with const-correctness on the
 dereference function.

 For the const_node_iterator, Value = const node_base, thus yielding

 {{{
 const node_base& dereference() const {
    return *m_node;
 }

 const node_base* m_node;
 }}}

 However, for node_iterator, Value = node_base:

 {{{
 node_base& dereference() const {
    return *m_node; // Error: cannot convert const variable to non_const
 reference
 }

 node_iterator* m_node;
 }}}

 Correct would be to const-overload dereference:

 {{{
 typedef boost::iterator_facade<
         node_iter<Value>
       , Value
       , boost::forward_traversal_tag
     > super;

 typename super::reference dereference() {
     return *m_node;
 }
 const typename super::reference dereference() const {
     return *m_node;
 }
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5888>
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