Re: [Boost-bugs] [Boost C++ Libraries] #3603: Fix warnings when compiling test cases

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #3603: Fix warnings when compiling test cases
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-11-19 07:28:12

#3603: Fix warnings when compiling test cases
-------------------------------------------+--------------------------------
 Reporter:  s.ochsenknecht@…               |       Owner:  vladimir_prus  
     Type:  Bugs                           |      Status:  new            
Milestone:  Boost 1.41.0                   |   Component:  program_options
  Version:  Boost 1.40.0                   |    Severity:  Cosmetic       
 Keywords:                                 |  
-------------------------------------------+--------------------------------

Comment(by s_ochsenknecht):

 I guess I found the problem, my first approach was due to
 misunderstanding. Sorry for confusion.

 Here is what the gcc manual says about this warning:
 {{{
 Warn if the return type of a function has a type qualifier such as const.
 For ISO C such a type qualifier has no effect, since the value returned by
 a function is not an lvalue.
 }}}

 So, the any cast is supposed to return "const T* const" due to the
 template parameter <const T>. Here is declaration of the any_cast:
 {{{
 template<typename ValueType> const ValueType * any_cast(const any *
 operand);
 }}}

 So, the line in detail/value_semantic.hpp has to be changed from:
 {{{
 const T* value = boost::any_cast<const T>(&value_store);
 }}}
 to
 {{{
 const T* value = boost::any_cast<T>(&value_store);
 }}}

 I attached a new any_cast_warning.2.patch and a test case any_warning.cpp

 Cheers,
 Sascha

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3603#comment:8>
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