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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: 2011-12-28 09:38:24

Hello Jeroen,

Jeroen Habraken <vexocide_at_[hidden]> writes:

> 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
>>>> 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.
> Actually, you are. The logs
> and
> 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.

Thanks for these explanations. Indeed this issue is distinct from my
original problem and maybe should be assigned an own Trac ticket.

>>>> Please note that I also submitted a bug report on this issue more than 6
>>>> weeks ago without any reaction so far:
>>>> <>
>> 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:
>> Best regards,
>> Torsten Maehne
> I can't comment on
> not (yet) sure what's going on there.

I've created a new minimal test case (attached) without the automatisation provided
by Boost.unit_test. It just uses iostream, Boost.rational, Boost.Fusion,
and Boost.Karma and compiles fine against Boost trunk (rev. 76203).
However, the same wrong and compiler-dependent output by the Karma rule
for an ADT remains. Maybe this test case is more suitable for debugging.

> Jeroen
> _______________________________________________
> Unsubscribe & other changes:

Best regards,


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