[Boost-bugs] [Boost C++ Libraries] #10520: Conversion warning in intrusive/detail/utilities.hpp

Subject: [Boost-bugs] [Boost C++ Libraries] #10520: Conversion warning in intrusive/detail/utilities.hpp
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-09-20 16:47:53

#10520: Conversion warning in intrusive/detail/utilities.hpp
------------------------------+------------------------
 Reporter:  mbradle@…         |      Owner:  igaztanaga
     Type:  Bugs              |     Status:  new
Milestone:  To Be Determined  |  Component:  intrusive
  Version:  Boost 1.56.0      |   Severity:  Cosmetic
 Keywords:                    |
------------------------------+------------------------
 Hello,

 When I compile the following simple code test.cpp

 {{{
 #include <boost/intrusive/detail/utilities.hpp>

 int main()
 {
   return 0;
 }
 }}}
 with g++ version 4.8.1, Boost 1.56, and the compilation line
 {{{
 g++ -I/home/mbradle/boost -Wconversion test.cpp
 }}}
 I get the warning
 {{{
 In file included from test.cpp:1:0:
 /home/mbradle/boost/boost/intrusive/detail/utilities.hpp: In function
 ‘float boost::intrusive::detail::fast_log2(float)’:
 /home/mbradle/boost/boost/intrusive/detail/utilities.hpp:592:18: warning:
 conversion to ‘float’ from ‘int’ may alter its value [-Wconversion]
     return (val + log_2);
                   ^
 }}}
 Casting log_2 as a float removes the warning, but, given that I do not get
 this warning if I compile against Boost 1.55 and that I see no difference
 between the fast_log2 routines in the two versions, I suspect that casting
 is not the correct fix.  Thanks, and best wishes.

 Brad Meyer

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10520>
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