Re: [boost] [1.36][ublas] VC8/SP1 with ADL problem?

From: Thomas Klimpel (Thomas.Klimpel_at_[hidden])
Date: 2008-08-09 08:19:13

> > 2. Do you have a quick fix workaround for this?
>
> How about "#define NDEBUG" :-)

A better workaround is "#define BOOST_UBLAS_NDEBUG". However, this does not really fix the ADL problem, but just avoids the use of "type_traits<double>::type_sqrt" and "type_traits<double>::type_abs" for this example.

> I'm no expert on ADL, so I have no idea whether
> VC8 is allowed to fail here.

I checked with VC9 and gcc-3.4.4 and they also fail. So this is probably not a bug in VC8, but a problem in ublas. I read a bit about ADL and came to the conclusion that an anonymous namespace might be one possible solution for this problem (see attached patch). At least it seems to work with both VC9 and gcc-3.4.4 for this example.

(The intention behind ADL seems to be that the compiler looks in the namespace of the argument of the method call. So the lookup in the boost::numeric namespace doesn't seem to be intended. The anonymous namespace should avoid the lookup in the boost::numeric namespace, but still allow the lookup in the namespace of the argument of the method call.)

Regards,
Thomas

-----Original Message-----
From: boost-bounces_at_[hidden] [mailto:boost-bounces_at_[hidden]] On Behalf Of Thomas Klimpel
Sent: Donnerstag, 7. August 2008 20:33
To: boost_at_[hidden]
Cc: ublas mailing list
Subject: Re: [boost] [1.36][ublas] VC8/SP1 with ADL problem?

Hello Markus,

> 1. Can you confirm this behaviour?

I can confirm this (VC8, debug).

> 2. Do you have a quick fix workaround for this?

How about "#define NDEBUG" :-)

I'm no expert on ADL, so I have no idea whether VC8 is allowed to fail
here. VC8 seems to fail as soon as I define any template function named
sqrt inside the boost or boost::numeric namespace. I have no idea how to
work around that. Perhaps I should investigate why "#define NDEBUG"
works around the problem.

> 3. Can this be fixed in future versions of boost

I don't even know what causes the problem in the first place. Moving
numeric/interval to a separate namespace would probably avoid the
current problem, but this is not what I would call "fixed".

I think you should report the problem to the ublas mailing list, where
you initially also reported your "non-boiled down" problem.

Regards,
Thomas

-----Original Message-----
From: boost-bounces_at_[hidden]
[mailto:boost-bounces_at_[hidden]] On Behalf Of Markus Werle
Sent: Mittwoch, 6. August 2008 11:28
To: boost_at_[hidden]
Subject: [boost] [1.36][ublas] VC8/SP1 with ADL problem?

Hi!

Posting to devel, since I believe sucking ADL may be the cause ...
I have a headache problem with VC8/SP1 which leads to some questions.

1. Can you confirm this behaviour?
2. Do you have a quick fix workaround for this?
3. Can this be fixed in future versions of boost

The following innocent looking piece of code (boiled down within 2 days
-sigh)

---snip---
#include <boost/numeric/interval.hpp>
#include <boost/numeric/ublas/traits.hpp>

#include <boost/numeric/ublas/vector.hpp>

namespace ublas = boost::numeric::ublas;

void trigger_ublas_compile_error()
{ 
        ublas::vector<double> boom = ublas::zero_vector<double>(5);
}
---EOF---

compiled with VC8 SP1 in DEBUG mode with a command line similar to
(some private include paths ripped off)

/Od /I "PATH_TO\boost_1_36_beta"  /D "WIN32" /D "_WINDOWS" /D "_DEBUG" 
/D "_CRT_SECURE_NO_WARNINGS" /D "_SCL_SECURE_NO_WARNINGS" 
/D "BOOST_PYTHON_STATIC_LIB" /D "_MBCS" /Gm /EHsc /RTC1 /MTd 
/Fo"Debug\\" /Fd"Debug\vc80.pdb" /W3 /nologo /c /ZI /TP 
/errorReport:prompt  /bigobj

bails out with

------ Build started: Project: XXXX, Configuration: Debug Win32 ------
Compiling...
TestBoostUblasError.cpp
[...]\boost_1_36_beta\boost\numeric\ublas\traits.hpp(97) : error C2784: 
'boost::numeric::interval<T,Policies> boost::numeric::sqrt
(const boost::numeric::interval<T,Policies> &)' : 
could not deduce template argument for 
'const boost::numeric::interval<T,Policies> &' from 'const double'
        [...]\boost_1_36_beta\boost\numeric\interval\arith2.hpp(198) : 
see declaration of 'boost::numeric::sqrt'
        [...]\boost_1_36_beta\boost\numeric\ublas\traits.hpp(93) : 
while compiling class template member function 
'double boost::numeric::ublas::scalar_traits<T>::type_sqrt(const double
&)'
        with
        [
            T=double
        ]
        [...]\boost_1_36_beta\boost\numeric\ublas\traits.hpp(151) : 
see reference to class template instantiation 
'boost::numeric::ublas::scalar_traits<T>' being compiled
        with
        [
            T=double
        ]
[...]\boost_1_36_beta\boost\numeric\ublas\traits.hpp(97) : 
fatal error C1903: unable to recover from previous error(s); 
stopping compilation
[...]
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped
==========

Ugly as it is: it will compile in any release mode, be it static or
dynamic 
linkage :-(

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