[Boost-bugs] [Boost C++ Libraries] #3249: ptr_list of const items

Subject: [Boost-bugs] [Boost C++ Libraries] #3249: ptr_list of const items
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-07-07 15:58:38

#3249: ptr_list of const items
---------------------------------+------------------------------------------
 Reporter:  matcatprg@…          |       Owner:  nesotto      
     Type:  Bugs                 |      Status:  new          
Milestone:  Boost 1.40.0         |   Component:  ptr_container
  Version:  Boost 1.35.0         |    Severity:  Problem      
 Keywords:                       |  
---------------------------------+------------------------------------------
 My code will not compile when I have a ptr_list of const abstract classes
 (i.e: boost::ptr_list<const abstract_class>). When I remove the const
 keyword, the code compiles and works fine. I'm using gcc 4.3 on Ubuntu
 GNU/Linux.

 Does the list need to be able to manipulate its items and therefore they
 can't be const? Or is it some bug? I noticed this line in the output:

 invalid conversion from ‘const void*’ to ‘void*’

 leading me to believe that it can't take consts. If it indeed can't take
 consts, you should mention it in the documentation or faq for
 ptr_container.


 Thanks,
 Matthew A. Todd


 Here is the output from the compiler:

 /usr/include/boost/ptr_container/ptr_sequence_adapter.hpp: In member
 function ‘void boost::ptr_sequence_adapter<T, VoidPtrSeq,
 CloneAllocator>::push_back(typename
 boost::ptr_container_detail::reversible_ptr_container<boost::ptr_container_detail::sequence_config<T,
 VoidPtrSeq>, CloneAllocator>::value_type) [with T = const BASE, VoidPtrSeq
 = std::list<void*, std::allocator<void*> >, CloneAllocator =
 boost::heap_clone_allocator]’:
 main.cpp:42:   instantiated from here
 /usr/include/boost/ptr_container/ptr_sequence_adapter.hpp:183: error:
 invalid conversion from ‘const void*’ to ‘void*’
 /usr/include/boost/ptr_container/ptr_sequence_adapter.hpp:183: error:
 initializing argument 1 of ‘void std::list<_Tp, _Alloc>::push_back(const
 _Tp&) [with _Tp = void*, _Alloc = std::allocator<void*>]’

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Ticket URL: <https://svn.boost.org/trac/boost/ticket/3249>
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