[Boost-bugs] [Boost C++ Libraries] #3489: using member objects as hooks

Subject: [Boost-bugs] [Boost C++ Libraries] #3489: using member objects as hooks
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-09-26 22:02:36

#3489: using member objects as hooks
------------------------------+---------------------------------------------
 Reporter:  anonymous         |       Owner:  igaztanaga
     Type:  Feature Requests  |      Status:  new       
Milestone:  Boost 1.41.0      |   Component:  intrusive 
  Version:  Boost 1.40.0      |    Severity:  Problem   
 Keywords:                    |  
------------------------------+---------------------------------------------
 boost intrusive supports base hooks and member hooks, but if you need
 something like the following you're off to writing value and node traits:

 struct B : list_base_hook<>{};

 struct A{
   B *b;
 };

 the value type of the list should be A, not B, so neither a base_hook nor
 a member hook can be used here.

 so I suggest to add code like the one attached to this ticket, which
 allows you to do this:


 struct get_b{
   B &operator()(A const &a){
     assert(a.b); return *a.b;
   }
 };

 list<A,member_object_hook<A,list_base_hook<>,get_b> > mylist;

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3489>
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