[Boost-bugs] [Boost C++ Libraries] #6191: Fix variable shadowing warning in igamma_inverse.hpp

Subject: [Boost-bugs] [Boost C++ Libraries] #6191: Fix variable shadowing warning in igamma_inverse.hpp
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-12-01 17:12:48

#6191: Fix variable shadowing warning in igamma_inverse.hpp
---------------------------------------------------+------------------------
 Reporter:  Vadim Zeitlin <vz-boost@…>             |       Owner:  johnmaddock
     Type:  Bugs                                   |      Status:  new        
Milestone:  To Be Determined                       |   Component:  math       
  Version:  Boost 1.48.0                           |    Severity:  Cosmetic   
 Keywords:                                         |  
---------------------------------------------------+------------------------
 A local variable `s` is redefined in `find_inverse_gamma()` helper defined
 in the file `math/special_functions/detail/igamma_inverse.hpp` resulting
 in annoyingly long warnings from Sun CC compiler (see below for the
 warning in its full glory). I suspect other compilers (e.g. g++ with
 `-Wshadow`) would give this warning as well so I'd like to ask for the
 following trivial patch to be applied to fix it:
 {{{
 #!diff
 --- igamma_inverse.hpp.orig     Thu Dec  1 18:00:20 2011
 +++ igamma_inverse.hpp  Thu Dec  1 18:01:27 2011
 @@ -279,7 +279,6 @@
           {
           // DiDonato and Morris Eq 35:
              T v = log(p) + boost::math::lgamma(ap1, pol);
 -            T s = 1;
              z = exp((v + w) / a);
              s = boost::math::log1p(z / ap1 * (1 + z / (a + 2)));
              z = exp((v + z - s) / a);
 }}}

 Removing the declaration and initialization shouldn't change the meaning
 of the existing code because the variable is not used before it's assigned
 below and the variable with the same name in enclosing scope is not used
 any more. But if you prefer you could also just rename this `s` in nested
 scope to something else (its initialization is still unneeded though).

 TIA!

 P.S. The warning:
 {{{
 ".../boost/math/special_functions/detail/igamma_inverse.hpp", line 282:
 Warning, wvarhidenmem: s hides the same name in an outer scope.
 ".../boost/math/special_functions/detail/igamma_inverse.hpp", line 406:
 Where, temwhileinst: While instantiating
 "boost::math::detail::find_inverse_gamma<double,
 boost::math::policies::policy<boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy>>(double, double, double, const
 boost::math::policies::policy<boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy>&, bool*)".
 ".../boost/math/special_functions/detail/igamma_inverse.hpp", line 406:
 Where, teminstfrom: Instantiated from
 boost::math::detail::gamma_p_inv_imp<double,
 boost::math::policies::policy<boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy>>(double, double, const
 boost::math::policies::policy<boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy,
 boost::math::policies::default_policy>&).
 ".../boost/math/special_functions/detail/igamma_inverse.hpp", line 517:
 Where, teminstend: Instantiated from non-template code.
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6191>
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