Hi Zeljko,
Zeljko Vrba wrote:
The following simple program crashes with assertion failure when compiled under
Solaris 11 with SunCC: Sun C++ 5.8 Patch 121018-10 2007/02/21
Assertion failed: node_algorithms::unique(to_insert),
file boost/boost/intrusive/list.hpp, line 168
I'm using the latest Boost.Intrusive from CVS (snapshot taken 2007-06-03).
I have tracked the problem, but I don't know wheter it's the code or compiler
problem; see below the code for cause.
Now I must confess it: Boost.Intrusive uses a non-standard and
non-portable hack to make member hooks as small as base hooks. This hack
uses the fact that for a member stored in a class or in a superclass
without any virtual inheritance relationship a pointer to member is just
the offset of that member in the class. This offset is encoded
differently for different compilers. If you see the file
boost/intrusive/detail/parent_from_member.hpp you have the following
function:
template
std::size_t offset_from_pointer_to_member(const Member Parent::*
ptr_to_member)
{
//The implementation of a pointer to member is compiler dependent.
#if defined(BOOST_MSVC) || defined(__GNUC__) || \
defined(BOOST_INTEL) || defined(__HP_aCC) || \
defined(__EDG_VERSION__)
//This works with gcc, msvc, edg, ac++
return *(const std::size_t*)(const void*)&ptr_to_member;
#else
//This is the traditional C-front approach: CW 9.4, dmc
return *(const std::size_t*)(const void*)&ptr_to_member - 1;
#endif
}
This function takes a pointer to member and tries to guess the offset
between the class that owns the member and the member. As you can see,
for Visual, Intel and GCC a pointer to data member it's just the offset.
For compilers like DMC and CW is the offset minus 1.
Since I don't have access to a SunCC compiler you will need to help me
discover how SunCC implements pointer to data members. I will need for
example the size of a pointer to data member (a simple
sizeof(ptr_to_member) would be enough), and what the binary value of of
that pointer to member for different layouts, say:
struct klass {
void *data_klass[N];
boost::intrusive::list_member_hook<> hook_;
typedef
boost::intrusive::list<
boost::intrusive::list_member_hook<>::value_traits<
klass, &klass::hook_>,
false> list;
};
changing the value of N. Willing to help?
Regards,
Ion
P.S.: I'm not sure if EDG-based compilers and HP compiler work because I
don't have such compilers. If someone wants to help on those, I would be
glad.
