Re: [Boost-bugs] [Boost C++ Libraries] #9378: g++ 4.7 -Wshadow warnings need attention

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #9378: g++ 4.7 -Wshadow warnings need attention
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-03-19 02:44:08

#9378: g++ 4.7 -Wshadow warnings need attention
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  Reporter:  Tom Browder <tom.browder@…>  |      Owner:  eric_niebler
      Type:  Bugs                         |     Status:  new
 Milestone:  To Be Determined             |  Component:  xpressive
   Version:  Boost 1.55.0                 |   Severity:  Problem
Resolution:                               |   Keywords:
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Comment (by steven_watanabe):

 Replying to [comment:10 rmann@…]:
 > Obviously it should be fixed by someone who knows what they're doing,
 but in this case it should be mechanical (identifying errors, of course,
 is not. But fixing them such that the code remains equivalent is).
 >

 Mechanically rewriting the code like this has no benefit
 to anyone.

 Either

 a. It's immediately obvious where each variable comes from, or
 b. It isn't obvious what a name refers to.

 If (a) is true, then rewriting the code will not make
 the code more understandable and in fact using mangled
 names can make it harder to follow.  Otherwise, the
 more (b) is true, the more likely it is that these
 mechanical changes will accidentally change the behavior.

 Besides which, if all you want to do is tell the compiler
 to shut up, the safest and most reliable solution is to
 do exactly that, i.e., #pragma GCC warning ignored -Wshadow.

 > Of course Boost can benefit. Right now, you have no idea if you are
 inadvertently referencing the wrong variable.

 I beg to differ.  I'm not.

 > disable_warnings.hpp and enable_warnings.hpp is a pretty hacky fix.

 I don't see why.  It means that library code can be compiled with the
 warning settings that the library author considers useful, rather
 than whatever each user wants.  Suppressing warnings is often necessary
 anyway (e.g. C4512: Assignment operator could not be generated.) and
 these headers are a lot more convenient than writing #ifdefs everywhere.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/9378#comment:11>
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