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: Torsten Maehne (Torsten.Maehne_at_[hidden])
Date: 2011-12-27 13:24:28

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:                 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.

>> 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
>
> _______________________________________________
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Best regards,

Torsten Maehne