Hi all,

I found a probable bug in mingw.
Here is the minimal code that can not compile:

#include <boost/ptr_container/ptr_list.hpp>

#include <iostream>

class A
{
public:
    A(const int id):_id(id){}
    virtual ~A()=0;
    bool operator==(const A& other) const { return _id == other._id; }
    int _id;
};

A::~A(){}

class B : public A
{
public:
    B(const int id):A(id){}
    virtual ~B() {}
};

class C : public A
{
public:
    C(const int id):A(id){}
    virtual ~C() {}
};

int main() {
    typedef boost::ptr_list<A> AList;
    AList a,b;
    a.push_back( new B(0) );
    a.push_back( new C(1) );
    b.push_back( new B(0) );
    b.push_back( new C(1) );

    return a == b;
}

And the compilation error:

gcc.compile.c++ T:\Analyse1\dist\lib\bin\gcc-mingw-4.3.0\debug\threading-multi\src\main.o
c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/boost_concept_check.h: In instantiation of '__gnu_cxx::_EqualOpConcept<A, A>':
c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/boost_concept_check.h:62:   instantiated from 'void __gnu_cxx::__function_requires() [with _Concept = __gnu_cxx::_EqualOpCon
cept<A, A>]'
c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/stl_algobase.h:943:   instantiated from 'bool std::equal(_II1, _II1, _II2) [with _II1 = boost::void_ptr_iterator<std::_List_
const_iterator<void*>, const A>, _II2 = boost::void_ptr_iterator<std::_List_const_iterator<void*>, const A>]'
T:\Analyse1\3rdParty\boost/boost/ptr_container/detail/reversible_ptr_container.hpp:531:   instantiated from 'bool boost::ptr_container_detail::reversible_ptr_container<Config, CloneA
llocator>::operator==(const boost::ptr_container_detail::reversible_ptr_container<Config, CloneAllocator>&) const [with Config = boost::ptr_container_detail::sequence_config<A, std::
list<void*, std::allocator<void*> > >, CloneAllocator = boost::heap_clone_allocator]'
tests\src\main.cpp:38:   instantiated from here
c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/boost_concept_check.h:296: error: cannot declare field '__gnu_cxx::_EqualOpConcept<A, A>::__a' to be of abstract type 'A'
tests\src\main.cpp:6: note:   because the following virtual functions are pure within 'A':
tests\src\main.cpp:14: note:    virtual A::~A()
c:\qt\mingw\bin\../lib/gcc/mingw32/4.3.0/include/c++/bits/boost_concept_check.h:296: error: cannot declare field '__gnu_cxx::_EqualOpConcept<A, A>::__b' to be of abstract type 'A'
tests\src\main.cpp:6: note:   since type 'A' has pure virtual functions

    "g++" -ftemplate-depth-128 -O0 -fno-inline -Wall -g -mthreads -DBOOST_SYSTEM_DYN_LINK=1 -I"T:\Analyse1\3rdParty\boost" -I"tests\src" -c -o "T:\Analyse1\dist\lib\bin\gcc-mingw-
4.3.0\debug\threading-multi\src\main.o" "tests\src\main.cpp"

The problem might come from this:

#define _GLIBCXX_DEFINE_BINARY_OPERATOR_CONSTRAINT(_OP,_NAME) \
template <class _Ret, class _First, class _Second> \
struct _NAME { \
    void __constraints() { (void)__constraints_(); } \
    _Ret __constraints_() { \
      return __a _OP __b; \
    } \
    _First __a; \
    _Second __b; \
}

I hope it comes from me and not from boost...
If anyone have an idea of what I can do to solve this, It would be great :)

Regards,
Eloi.