Re: [Boost-bugs] [Boost C++ Libraries] #11801: Recursive modify in multi_index sometimes does not update index correctly

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #11801: Recursive modify in multi_index sometimes does not update index correctly
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-11-19 16:55:15

#11801: Recursive modify in multi_index sometimes does not update index correctly
-------------------------------------+-------------------------------------
  Reporter:  Valentyn Shtronda       |      Owner:  joaquin
  <valiko.ua@…>                      |     Status:  closed
      Type:  Bugs                    |  Component:  multi_index
 Milestone:  To Be Determined        |   Severity:  Problem
   Version:  Boost 1.59.0            |   Keywords:  multi_index
Resolution:  invalid                 |  multi_index_container recursive
                                     |  modify
-------------------------------------+-------------------------------------

Comment (by joaquin):

 This is a combination of the previous solutions, probably somewhat faster
 as it incurs in fewer reindexings:

 {{{
 bool succeeded = deps_map.modify(it,
     [=](node_info_t& node_info)
     {
         if (node_info.deps.size() == 0)
         {
             node_info.layer = 0;
         }
         else
         {
             index_by_name_t& index_by_name = deps_map.get<by_name>();
             node_info.layer = CALCULATION_IN_PROGRESS;
             index_by_name.modify(it,[](node_info_t&){});
             int layer = 0;
             for (const std::string& dep_name : node_info.deps)
             {
                 index_by_name_t::iterator dep_it =
 index_by_name.find(dep_name);
                 if (dep_it == deps_map.end())
                 {
                     node_info.layer = UNINITIALIZED;
                     printf("Unknown dependency.\n");
                     return;
                 }
                 if (!calc_layer(dep_it))
                 {
                     node_info.layer = UNINITIALIZED;
                     return;
                 }
                 layer = std::max(layer, dep_it->layer + 1);
             }
             node_info.layer = layer;
         }
     });
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/11801#comment:5>
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