Hi, On 27 December 2011 00:51, Torsten Maehne <Torsten.Maehne@gmx.de> wrote:
Hello,
I'm using Boost.Spirit.Karma to format the output of some nested structs (direct access of the public member variables) and abstract data types (ADTs) (access to the private member variables via getters and setters) in my code. I'm using Boost.Fusion to adapt the ADTs into a sequence of values of primitive data types for output with Boost.Karma. This worked fine till Boost 1.44. Since Boost 1.45 up till 1.48 and the current Boost trunk (I tested svn revs 75505, 75963, and 76196) the output of unsigned integer members of Boost.Fusion-adapted ADTs doesn't work anymore -- even though I took into account the change in the name of macro from BOOST_FUSION_ADAPT_CLASS to BOOST_FUSION_ADAPT_ADT as well as the additionally required header boost/spirit/include/support_adapt_adt_attributes.hpp.
The problem is demonstrated in the attached test case for rational number ADTs and structs, which use signed integer member variables. Compilation of this test case against Boost 1.44.0 will succeed and it will run without any errors. Compilation of this test case against Boost 1.45.0 and 1.46.1 will fail. Compilation against Boost 1.47.0 and 1.48.0 will succeed, but the output of negative values of signed integer members of Boost.Fusion-adapted ADTs will be wrong. The minus sign is output correctly, but it is followed by a wrong value, which seems to be yielded by a cast from a signed to an unsigned integer value instead of taking the absolute value of the signed integer value. This has been observed on Mac OS X 10.7.2 (x86_64) with Xcode 4.2 using Apple's g++ 4.2.1, Apple's clang++ 3.0. Interestingly, compiling the test case against Boost 1.47.0 or Boost 1.48.0 using MacPorts g++ 4.5.3, will yield more output checks to fail for Boost.Fusion-adapted ADTs used in Karma output rules.
Compilation against Boost from the Subversion trunk (I tested revs. 75505, 75963, and 76196) does only succeed using Apple's clang++ 3.0 and execution will yield the same wrong output for negative values of signed integer members of Boost.Fusion-adapted ADTs. Compilation fails with Apple's g++ 4.2.1 and MacPorts g++ 4.5.3.
I'm not able to locate the root cause for this problem, whether it is in Boost.Fusion or Boost.Spirit.Karma. I would appreciate any help to resolve this annoying issue. Until a solution is found, I'm stuck with Boost 1.44.0.
Several things seem to play a role, but I've had a look at as to why the code doesn't compile using boost-trunk and found the cause to be an ambiguity: boost/typeof/native.hpp:30:9: error: reference to 'enable_if' is ambiguous boost/utility/enable_if.hpp:36:10: error: candidates are: template<class Cond, class T> struct boost::enable_if boost/test/tree/decorator.hpp:184:23: error: class boost::unit_test::decorator::enable_if As enable_if is often used without being fully qualified this breaks in a major fashion. Since boost/test/tree/decorator.hpp seems to be quite new (added 2011-10-02 11:00:16 +0200) it might be best fixed there.
Please note that I also submitted a bug report on this issue more than 6 weeks ago without any reaction so far:
<https://svn.boost.org/trac/boost/ticket/6126>
Best regards,
Torsten Maehne
Note: I've included boost@lists.boost.org in the discussion. Kind regards, Jeroen Habraken