[Boost-bugs] [Boost C++ Libraries] #12745: key_nodeptr_comp broken if the key type is void*

Subject: [Boost-bugs] [Boost C++ Libraries] #12745: key_nodeptr_comp broken if the key type is void*
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2017-01-10 19:16:30

#12745: key_nodeptr_comp broken if the key type is void*
------------------------------+------------------------
 Reporter:  andysem           |      Owner:  igaztanaga
     Type:  Bugs              |     Status:  new
Milestone:  To Be Determined  |  Component:  intrusive
  Version:  Boost 1.63.0      |   Severity:  Problem
 Keywords:                    |
------------------------------+------------------------
 This is a regression since 1.60. `boost::intrusive::set::insert_check()`
 fails to compile if called with a key that has type `void*`. The error is
 as follows:

 {{{
 /home/lastique/src/boost-
 xcoder/boost/intrusive/detail/key_nodeptr_comp.hpp:87: error: no match for
 call to
 ‘(MediaBufferBase::callback_list::callback_reference::order_by_key) (const
 MediaBufferBase::callback_list::callback_reference&)’
     {  return base().get()(key_of_value()(*traits_->to_value_ptr(t1)));  }
               ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 }}}

 The problem is in `key_nodeptr_comp` implementation, which has an overload
 of `operator()` whith two formal parameters, the second one being used for
 `enable_if_c` and having the type `void*`. This operator calls user's
 ordering predicate with only one argument, which is naturally not
 expected.

 The suggested solution is to use SFINAE on the return type of the
 operators or use a more distinct type for the hidden argument of the
 operators.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/12745>
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