Re: [Boost-bugs] [Boost C++ Libraries] #9338: VS2005 compiler errors in swap() definition after including container/memory_util.hpp

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #9338: VS2005 compiler errors in swap() definition after including container/memory_util.hpp
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-11-17 13:16:49

#9338: VS2005 compiler errors in swap() definition after including
container/memory_util.hpp
----------------------------------------+------------------------
  Reporter:  Fedor Trushkin <ted-xp@…>  |      Owner:  igaztanaga
      Type:  Bugs                       |     Status:  new
 Milestone:  To Be Determined           |  Component:  container
   Version:  Boost 1.54.0               |   Severity:  Problem
Resolution:                             |   Keywords:
----------------------------------------+------------------------

Comment (by igaztanaga):

 If the template argument "Fun" has a member swap defined as:

 {{{

 struct Func
 {
   void swap() const
   {}
 };

 }}}

 Then the trait would lie and it would tell us that such member does not
 exist (the wrapper is a derived class that hides the base method). If you
 replace

 {{{

 boost_intrusive_has_member_function_callable_with::private_type swap()
 const;

 }}}

 with (variadic version)

 {{{

 boost_intrusive_has_member_function_callable_with::private_type swap(...)
 const;

 }}}

 then a compilation error would be triggered as

 {{{

 boost::move_detail::declval<FunWrap>().swap()

 }}}

 would be ambiguous (the compiler does not know if the variadic version
 from the wrapper or the base zero argument version should be called.

 In non-zero argument cases, a special argument "dont_care" is used
 generated a very different member overload. If that is selected, then the
 member does not exist. With 0 arguments, this is not possible.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/9338#comment:4>
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