Re: [boost] [Spirit-general] [karma][fusion] Signed integer members of Boost.Fusion adapted ADTs are not output correctly with Boost.Spirit.Karma rules

Subject: Re: [boost] [Spirit-general] [karma][fusion] Signed integer members of Boost.Fusion adapted ADTs are not output correctly with Boost.Spirit.Karma rules
From: Jeroen Habraken (vexocide_at_[hidden])
Date: 2011-12-27 14:14:14

Hi,

On 27 December 2011 19:24, Torsten Maehne <Torsten.Maehne_at_[hidden]> wrote:
> Hello Jeroen,
>
> thank you for looking on my test case on Boost trunk! Unfortunately,
> Boost trunk doesn't seem to be in a good shape currently for my test
> case, as it seems to trigger additional unrelated problems. Boost 1.48.0
> seems to be currently a more suitable starting point for a diagnosis of
> the original problem.
>
> Please see my comment below regarding your suggestion.
>
> Jeroen Habraken wrote:
>
>> Hi,
>>
>> On 27 December 2011 00:51, Torsten Maehne <Torsten.Maehne_at_[hidden]> 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: Â  Â  Â  Â  Â  Â  Â  Â  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.
>>
>
> On my side, I was not able to reproduce the "enable_if is ambiguous"
> error related to Boost.unit_test that you've observed. I tried with
> Apple g++ 4.2.1 and MacPorts g++ 4.5.3.

Actually, you are. The logs
https://svn.boost.org/trac/boost/attachment/ticket/6126/test_signed_integer_output_with_karma_boost_trunk_gcc42.log
and https://svn.boost.org/trac/boost/attachment/ticket/6126/test_signed_integer_output_with_karma_boost_trunk_gcc45.log
show:

/opt/boost-trunk/include/boost/fusion/iterator/equal_to.hpp:77: error:
expected nested-name-specifier before ‘enable_if’
/opt/boost-trunk/include/boost/fusion/iterator/equal_to.hpp:77: error:
expected initializer before ‘<’ token

These occur because the code states "typename enable_if<Cond,
T>::type" and the typename doesn't make sense in combination with
boost::unit_test::decorator::enable_if. When you remove the typename
(which is essentially what I did when debugging) you'll get the
ambiguity error.

>>> 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>
>
> This ticket contains compile logs of my tests with the two mentioned
> compilers.
>
>>> Best regards,
>>>
>>> Torsten Maehne
>>
>> Note: I've included boost_at_[hidden] in the discussion.
>>
>
> I hope that someone has an idea how to proceed further to separate the
> different problems. My original test case was designed to just expose
> the signed integer output problem. I used Boost.unit_test to facilitate
> its integration into a test suite. Now it seems to cause further side
> effects... at least on your side.
>
>> Kind regards,
>> Jeroen Habraken
>>
>> _______________________________________________
>> Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
>
> Best regards,
>
> Torsten Maehne

I can't comment on
https://svn.boost.org/trac/boost/attachment/ticket/6126/test_signed_integer_output_with_karma_boost148_gcc42_clang3.log,
not (yet) sure what's going on there.

Jeroen