[boost] [BGL] [variant] problem (and perhaps solution?) with strong_components.hpp and variant

29 Oct 2009

      Hi,

it seems the problem is indeed a conflict between the get function of
variant.hpp and the get function of two_bit_color_map. After renaming
get by getTEST in

1) two_bit_color_map.hpp line 61
2) breadth_first_search.hpp line 78
3) property_map.hpp line 164

the compiling error has disappeared.

Of course it is certainly not the right way to fix that bug, maybe
wrapping two_bit_color_map get (and alike) function name under some
namespace... but I'm not confident enough to take such decision. Maybe
there is a better way.

Please if someone is more knowledgeable could help me fix that bug.

Thanks for your help
Nil

On Tue, Oct 27, 2009 at 7:31 AM, Nil Geisweiller
<ngeiswei@googlemail.com> wrote:
...
Hi,
I resend that email with the right title header.
---------- Forwarded message ----------
From: Nil Geisweiller <ngeiswei@googlemail.com>
Date: Sun, Oct 25, 2009 at 6:11 PM
Subject: [Graph] problem with strong_components.hpp and variant
To: boost@lists.boost.org
Hi,
it seems there is a conflict between strong_components.hpp and
variant, maybe the method boost::get is wrongly overloaded.
The problem occurs with 1.40 but not with 1.37, and it is still occurs
with the last svn.
I attach a minimal code to reproduce the bug + compile error
######
test.cpp
######
//uncomment the line below to get the bug
#include <boost/graph/strong_components.hpp>
#include <boost/variant.hpp>
typedef boost::variant < int, float > intorfloat;
int main() {
 int i(2);
 intorfloat iof(i);
 return boost::get<int>(iof); //problem is here
}
###########
compile error
###########
a-lin@a-lin-desktop:~/OpenCog/test/bin$ make
[100%] Building CXX object CMakeFiles/test.dir/test.cpp.o
In file included from /usr/include/boost/graph/graph_concepts.hpp:17,
                from /usr/include/boost/graph/depth_first_search.hpp:18,
                from /usr/include/boost/graph/strong_components.hpp:17,
                from /home/a-lin/OpenCog/test/test.cpp:2:
/usr/include/boost/property_map/property_map.hpp: In instantiation of
‘boost::property_traits<int>’:
/usr/include/boost/graph/two_bit_color_map.hpp:46:   instantiated from
‘boost::two_bit_color_map<int>’
/home/a-lin/OpenCog/test/test.cpp:10:   instantiated from here
/usr/include/boost/property_map/property_map.hpp:31: error: ‘int’ is
not a class, struct, or union type
/usr/include/boost/property_map/property_map.hpp:32: error: ‘int’ is
not a class, struct, or union type
/usr/include/boost/property_map/property_map.hpp:33: error: ‘int’ is
not a class, struct, or union type
/usr/include/boost/property_map/property_map.hpp:34: error: ‘int’ is
not a class, struct, or union type
make[2]: *** [CMakeFiles/test.dir/test.cpp.o] Error 1
make[1]: *** [CMakeFiles/test.dir/all] Error 2
make: *** [all] Error 2
Is it a bug? Thanks a lot!
Nil