Re: [boost] [Serialization] Private destructors and extended_type_info_typeid

From: Paul Roberts (usenet_at_[hidden])
Date: 2008-03-23 15:20:49

Robert Ramey wrote:
 > it would seem to me that a private constructor in this context
 >  is a compile time error.
 >
 > In this case we've got
 >
 > A A::a;
 >
 > created at pre-main time by the C++ runtime initialization.  The
 > constructor is public - as it must be to be used in this way. By
 > the same token, the destructor would have to be public also.
 >

Sorry, Robert, that was an unfortunate and distracting artifact of my 
repro case. Here's another repro without the static instance of A.

Here, we have class B containing an instance of A, and A lists B as a 
friend, so A's private destructor is legal. The error in 
boost/serialization/extended_type_info_typeid.hpp is the same.

--
Paul Roberts
paul at pwroberts dot com
http://www.m3fe.com/

#include <boost/serialization/access.hpp>
#include <boost/archive/binary_oarchive.hpp>
#include <fstream>

class A
{
        friend class boost::serialization::access;
        friend class B;
private:
        A() {}
        ~A() {}

        template<typename Archive> void serialize(Archive& ar, const unsigned int version)
        {
        }
};

class B
{
        friend class boost::serialization::access;
        A a;

        template<typename Archive> void serialize(Archive& ar, const unsigned int version)
        {
                ar << a;
        }
};

int main()
{
        std::ofstream ofs("hi");
        {
                boost::archive::binary_oarchive oa(ofs);
                B b;
                oa << b;
        }
}

/*
1>------ Build started: Project: 2k8test, Configuration: Release Win32 ------
1>Compiling...
1>serialization_fun.cpp
1>C:\dev\boost-trunk\boost/serialization/extended_type_info_typeid.hpp(118) : error C2248: 'A::~A' : cannot access private member declared in class 'A'
1>        .\serialization_fun.cpp(16) : compiler has generated 'A::~A' here
1>        .\serialization_fun.cpp(6) : see declaration of 'A'
1>        C:\dev\boost-trunk\boost/serialization/extended_type_info_typeid.hpp(117) : while compiling class template member function 'void boost::serialization::extended_type_info_typeid<T>::destroy(const void *const ) const'
1>        with
1>        [
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(110) : see reference to class template instantiation 'boost::serialization::extended_type_info_typeid<T>' being compiled
1>        with
1>        [
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(107) : while compiling class template member function 'boost::archive::detail::oserializer<Archive,T>::oserializer(void)'
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(234) : see reference to class template instantiation 'boost::archive::detail::oserializer<Archive,T>' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(228) : while compiling class template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::save_standard::invoke(Archive &,const T &)'
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(292) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>::save_standard' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(280) : while compiling class template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::invoke(Archive &,const T &)'
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(498) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/common_oarchive.hpp(64) : see reference to function template instantiation 'void boost::archive::save<Archive,const T>(Archive &,const T &)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/array/oarchive.hpp(118) : see reference to function template instantiation 'void boost::archive::detail::common_oarchive<Archive>::save_override<const T>(T &,int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/basic_binary_oarchive.hpp(64) : see reference to function template instantiation 'void boost::archive::array::oarchive<Archive>::save_override<T>(const T &,unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/binary_oarchive_impl.hpp(45) : see reference to function template instantiation 'void boost::archive::basic_binary_oarchive<Archive>::save_override<T>(const T &,int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/interface_oarchive.hpp(63) : see reference to function template instantiation 'void boost::archive::binary_oarchive_impl<Archive,Elem,Tr>::save_override<T>(T &,int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            Elem=char,
1>            Tr=std::char_traits<char>,
1>            T=A
1>        ]
1>        .\serialization_fun.cpp(25) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_oarchive<Archive>::operator <<<A>(T &)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=A
1>        ]
1>        C:\dev\boost-trunk\boost/serialization/access.hpp(109) : see reference to function template instantiation 'void B::serialize<Archive>(Archive &,const unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive
1>        ]
1>        C:\dev\boost-trunk\boost/serialization/serialization.hpp(81) : see reference to function template instantiation 'void boost::serialization::access::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/serialization/serialization.hpp(140) : see reference to function template instantiation 'void boost::serialization::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(147) : see reference to function template instantiation 'void boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(139) : while compiling class template member function 'void boost::archive::detail::oserializer<Archive,T>::save_object_data(boost::archive::detail::basic_oarchive &,const void *) const'
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(234) : see reference to class template instantiation 'boost::archive::detail::oserializer<Archive,T>' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(228) : while compiling class template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::save_standard::invoke(Archive &,const T &)'
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(292) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>::save_standard' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(280) : while compiling class template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::invoke(Archive &,const T &)'
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/oserializer.hpp(498) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/common_oarchive.hpp(64) : see reference to function template instantiation 'void boost::archive::save<Archive,const T>(Archive &,const T &)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/array/oarchive.hpp(118) : see reference to function template instantiation 'void boost::archive::detail::common_oarchive<Archive>::save_override<const T>(T &,int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/basic_binary_oarchive.hpp(64) : see reference to function template instantiation 'void boost::archive::array::oarchive<Archive>::save_override<T>(const T &,unsigned int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/binary_oarchive_impl.hpp(45) : see reference to function template instantiation 'void boost::archive::basic_binary_oarchive<Archive>::save_override<T>(const T &,int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>        C:\dev\boost-trunk\boost/archive/detail/interface_oarchive.hpp(63) : see reference to function template instantiation 'void boost::archive::binary_oarchive_impl<Archive,Elem,Tr>::save_override<T>(T &,int)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            Elem=char,
1>            Tr=std::char_traits<char>,
1>            T=B
1>        ]
1>        .\serialization_fun.cpp(35) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_oarchive<Archive>::operator <<<B>(T &)' being compiled
1>        with
1>        [
1>            Archive=boost::archive::binary_oarchive,
1>            T=B
1>        ]
1>Build log was saved at "file://c:\dev\work\2k8test\Release\BuildLog.htm"
1>2k8test - 1 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
*/