Re: [Boost-bugs] [Boost C++ Libraries] #10462: throw exception inherits two std::exception

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #10462: throw exception inherits two std::exception
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-09-05 03:03:19

#10462: throw exception inherits two std::exception
-------------------------------------+------------------------------------
  Reporter:  gilles.guerre-chaley@…  |      Owner:  emildotchevski
      Type:  Bugs                    |     Status:  new
 Milestone:  To Be Determined        |  Component:  exception
   Version:  Boost 1.56.0            |   Severity:  Optimization
Resolution:                          |   Keywords:  visual studio 2013 x64
-------------------------------------+------------------------------------

Comment (by emildotchevski):

 There are checks which should fail with ambiguous implicit conversion
 errors in case std::exception is derived from multiple times. I'm
 noticing, however, that the relevant unit test throw_exception_test.cpp
 doesn't explicitly verify this.

 Could you help me diagnose the error? Insert the following snipped into
 throw_exception_test.cpp, run it, and let me know if it fails for you. It
 works on my darwin build (the idea of this insertion is that if
 std::exception is derived from multiple times, the catch(std::exception&)
 would fail since the conversion would be ambiguous.)


 {{{
 @@ -76,7 +76,21 @@ throw_fwd( void (*thrower)(int) )
      {
      try
          {
 -        thrower(42);
 +        try
 +            {
 +            thrower(42);
 +            }
 +        catch(
 +        std::exception & )
 +            {
 +            throw;
 +            }
 +        catch(
 +        ... )
 +            {
 +            BOOST_ERROR("throw_fwd failed to catch std::exception,
 possibly because it was derived from multiply.");
 +            throw;
 +            }
          }
      catch(
      boost::exception & x )

 }}}

 Thanks,
 Emil

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10462#comment:1>
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