[Boost-bugs] [Boost C++ Libraries] #12478: boost::atomic< char* > generates warning on fetch_add on gcc 4.8+

Subject: [Boost-bugs] [Boost C++ Libraries] #12478: boost::atomic< char* > generates warning on fetch_add on gcc 4.8+
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2016-09-23 17:50:45

#12478: boost::atomic< char* > generates warning on fetch_add on gcc 4.8+
--------------------------------------+--------------------------
 Reporter:  Matt Hauck <matthauck@…>  |      Owner:  timblechmann
     Type:  Bugs                      |     Status:  new
Milestone:  To Be Determined          |  Component:  atomic
  Version:  Boost 1.61.0              |   Severity:  Problem
 Keywords:                            |
--------------------------------------+--------------------------
 I have a `boost::atomic< char* >` object, on which I am calling
 `fetch_add` with `ptrdiff_t`, and apparently only on gcc 4.8+, I am
 getting the following warning:

 {{{
 In file included from
 /home/foo/packages/boost_1_61_0/include/boost/atomic/detail/atomic_template.hpp:25:0,
                  from
 /home/foo/packages/boost_1_61_0/include/boost/atomic/atomic.hpp:22,
                  from
 /home/foo/packages/boost_1_61_0/include/boost/atomic.hpp:12,
                  from /home/foo/code/ThingThatUsesAtomic.h:0,
 /home/foo/packages/boost_1_61_0/include/boost/atomic/detail/bitwise_cast.hpp:
 In instantiation of ‘To boost::atomics::detail::bitwise_cast(const From&)
 [with To = char*; From = long unsigned int]’:
 /home/foo/packages/boost_1_61_0/include/boost/atomic/detail/atomic_template.hpp:449:59:
 required from ‘T* boost::atomics::detail::base_atomic<T*,
 void*>::fetch_add(boost::atomics::detail::base_atomic<T*,
 void*>::difference_type, boost::memory_order) volatile [with T = char;
 boost::atomics::detail::base_atomic<T*, void*>::value_type = char*;
 boost::atomics::detail::base_atomic<T*, void*>::difference_type = long
 int]’
 [ actual code references redacted ... ]
 /home/foo/packages/boost_1_61_0/include/boost/atomic/detail/bitwise_cast.hpp:41:5:
 warning: casting ‘char*’ to ‘char&’ does not dereference pointer
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/12478>
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