[Boost-bugs] [Boost C++ Libraries] #7507: BGL subgraph copy constructor buggy

Subject: [Boost-bugs] [Boost C++ Libraries] #7507: BGL subgraph copy constructor buggy
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-10-15 14:45:45

#7507: BGL subgraph copy constructor buggy
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 Reporter:  Amyn Bennamane <amynbe@…>                 |       Owner:  jewillco
     Type:  Bugs                                      |      Status:  new     
Milestone:  To Be Determined                          |   Component:  graph   
  Version:  Boost 1.51.0                              |    Severity:  Problem 
 Keywords:  copy-on-write, subgraph copy constructor  |  
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 Hello,

 I store subgraph objects in a std::list.

 After this, most of the data contained in subgraphs are lost.

 Attached is a minimalist code that creates a root graph and two childen,
 and then displays them directly, then insert them into a (copy-on-write)
 list, then displays them again.

 The root redisplays too much, and children lose data.

 I am on MacOSX with gcc 6; maybe on other platforms the copy would not
 happen, since I don't modify the graphs between insertion and display.

 Here is my output:

 {{{

 From the stack:
 (root) graph: 6(0,2) 4(1,2)
 num_edges= 2
 subgraph: 0(0,1)
 num_edges= 1
 subgraph: 0(0,1)
 num_edges= 1

 From list:
 graph: 0(0,1) 1(1,2) 2(1,3) 6(2,5) 3(4,1) 4(4,5) 5(5,3)
 num_edges= 7
 graph:
 num_edges= 0
 graph:
 num_edges= 0
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7507>
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