[Boost-bugs] [Boost C++ Libraries] #10975: The name exception is ambiguous, exception and std::exception.

Subject: [Boost-bugs] [Boost C++ Libraries] #10975: The name exception is ambiguous, exception and std::exception.
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-01-28 05:26:53

#10975: The name exception is ambiguous, exception and std::exception.
------------------------------+--------------------------------
 Reporter:  Sergey.Sprogis@…  |      Owner:  grafik
     Type:  Bugs              |     Status:  new
Milestone:  To Be Determined  |  Component:  Regression Testing
  Version:  Boost 1.57.0      |   Severity:  Problem
 Keywords:                    |
------------------------------+--------------------------------
 1. Description of the failure.

 On Solaris 11.2  Oracle Studio 12.4 C++ compiler under -std=c++11 option
 produces the following error messages for
 libs/spirit/classic/test/match_tests.cpp  test.

 "/usr/include/math.h", line 215: Error: The name exception is ambiguous,
 exception and std::exception.
 "/usr/include/math.h", line 215: Error: The name exception is ambiguous,
 exception and std::exception.
 ".../boost/exception/exception.hpp", line 140: Error: The name exception
 is ambiguous, exception and std::exception.


 and actually it produces similar error messages for small test like this:

  namespace boost {
   class exception;
  }
  using namespace boost;
  #include <algorithm>

 or like this:

  class exception;
  using namespace std;
  #include <algorithm>

 Note that in the original boost harness "class exception;" can be found
 inside: boost/exception/exception.hpp

 2. Cause of the failure.


 This is a C++ vs Unix or Boost vs Unix issue.

 Standard Unix requires "struct exception" in the global namespace when
 <math.h> is included. This conflicts with std::exception or
 boost::exception,
 but only when there are using-declarations or using-directives that bring
 std::exception or boost::exception into the global namespace.

 When <math.h> is included, user code must avoid all of the following at
 file
 scope (in the global namespace):
 using namespace std;
 using namespace boost;
 using std::exception;
 using boost::exception;

 3. Possible Solution.

  - Remove  line:

      using namespace std;

  - Replace all 'cout' invocations with 'std::cout'

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10975>
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