Re: [Boost-users] Serialization: how to serialize c style strings?

16 Jun 2005


      Serialization of c style strings was excluded on purpose.  The motivation
for this was in large part the security issues involved.  Then there was the
problem of stings with spaces in them when writing to text output/input.
You can so this with the binary_object wrappers which handles the length,
memory pair.   My view was that the std::string was as good or better than
anything else I would use for this.

Robert Ramey


Tom Thorne wrote:
...
I'm trying to understand how to go about serializing allocated c style
string buffers using the serialization library.
The example code below gives a compile error (see bottom)
"left of '.serialize' must have class/struct/union type"
and I don't see how to fix this. Could someone point me in the right
direction?
In the meantime I'm using std::string, but this doesn't meet my needs.
Many thanks for any help.  Tom
-----------------------------
#include <boost/serialization/string.hpp>
#include <fstream>
#include <boost/archive/text_oarchive.hpp>
#include <boost/archive/text_iarchive.hpp>
template<class T>
class test
{
public:
template<class Archive>
  void serialize(Archive &ar, const unsigned int version)
  {
    ar & boost::serialization::make_nvp("p", p);
  }
test()
  {
    p = 0;
  }
  ~test()
  {
    delete p;
  }
  explicit test(const T *t)
  {
    size_t len = std::char_traits<T>::length(t);
    p = new T[len+1];
    std::char_traits<T>::copy(p, t, len+1);
  }
  const T *get() const
  {
    return p;
  }
private:
T *p;
};
void sertest()
{
  test<char> t("Hello");
std::ofstream ofs("test.txt");
  boost::archive::text_oarchive oa(ofs);
oa << t;
  ofs.close();
}
------------------------------
------ Build started: Project: test, Configuration: Debug Win32 ------
Compiling...
sertest.cpp
c:\Proj\boost\include\boost-1_32\boost\serialization\access.hpp(106) :
error C2228: left of '.serialize' must have class/struct/union type
        type is 'type'
c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(7
8) : see reference to function template instantiation 'void
boost::serialization::access::serialize<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(1
21) : see reference to function template instantiation 'void
boost::serialization::serialize<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(15
2) : see reference to function template instantiation 'void
boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\extended_type_info_
typeid.hpp(100) : while compiling class-template member function 'void
boost::archive::detail::oserializer<Archive,T>::save_object_data(boost::
archive::detail::basic_oarchive &,const void *) const'
        with
        [
            Archive=boost::archive::text_oarchive,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(16
3) : see reference to class template instantiation
'boost::archive::detail::oserializer<Archive,T>' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(16
2) : while compiling class-template member function 'const
boost::archive::detail::basic_oserializer
&boost::archive::detail::pointer_oserializer<T,Archive>::get_basic_seria
lizer(void) const'
        with
        [
            T=type,
            Archive=boost::archive::text_oarchive
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(53
0) : see reference to class template instantiation
'boost::archive::detail::pointer_oserializer<T,Archive>' being
        compiled with
        [
            T=type,
            Archive=boost::archive::text_oarchive
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive
.hpp(65) : see reference to function template instantiation 'const
boost::archive::detail::basic_pointer_oserializer
&boost::archive::detail::instantiate_pointer_oserializer<Archive,T>(Arch
ive *,T *)' being compiled
        with
        [
            Archive=boost::ar
chive::text_oarchive,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(33
2) : see reference to function template instantiation 'const
boost::archive::detail::basic_pointer_oserializer
*boost::archive::detail::interface_oarchive<Archive>::register_type<T>(T
*)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(33
1) : while compiling class-template member function 'const
boost::archive::detail::basic_pointer_oserializer
*boost::archive::detail::save_pointer_type<Archive,TPtr>::non_abstract<T
...
...
...
register_type(Archive &)'
        with
        [
            Archive=boost::archive::text_oarchive,
            TPtr=char *,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(34
9) : see reference to class template instantiation
'boost::archive::detail::save_pointer_type<Archive,TPtr>::non_abstract<T
...
' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            TPtr=char *,
            T=type
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(47
5) : see reference to function template instantiation 'const
boost::archive::detail::basic_pointer_oserializer
*boost::archive::detail::save_pointer_type<Archive,TPtr>::register_type<
...
(Archive &,T &)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            TPtr=char *,
            T=char
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(46
2) : while compiling class-template member function 'void
boost::archive::detail::save_pointer_type<Archive,TPtr>::invoke(Archive
&,const TPtr)'
        with
        [
            Archive=boost::archive::text_oarchive,
            TPtr=char *
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(55
1) : see reference to class template instantiation
'boost::archive::detail::save_pointer_type<Archive,TPtr>' being
        compiled with
        [
            Archive=boost::archive::text_oarchive,
            TPtr=char *
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\basic_text_oarchive.hpp(7
1) : see reference to function template instantiation 'void
boost::archive::save<Archive,T>(Archive &,const T & )' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=char *
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive
.hpp(80) : see reference to function template instantiation 'void
boost::archive::basic_text_oarchive<Archive>::save_override<T>(const
T & ,int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=char *
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive
.hpp(110) : see reference to function template instantiation 'Archive
&boost::archive::detail::interface_oarchive<Archive>::operator
<<<T>(const T & )' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=char *
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\nvp.hpp(58)
...
see reference to function template instantiation 'Archive
&boost::archive::detail::interface_oarchive<Archive>::operator &<T>(T
& )' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=char *
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\access.hpp(106) :
see reference to function template instantiation 'void
boost::serialization::nvp<T>::serialize<Archive>(Archive &,const
unsigned int) const' being compiled
        with
        [
            T=char *,
            Archive=boost::archive::text_oarchive
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(7
8) : see reference to function template instantiation 'void
boost::serialization::access::serialize<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(1
21) : see reference to function template instantiation 'void
boost::serialization::serialize<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(22
7) : see reference to function template instantiation 'void
boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(22
2) : while compiling class-template member function 'void
boost::archive::detail::save_non_pointer_type<Archive,T>::save_only::inv
okex(Archive &,const T &)'
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(30
9) : see reference to class template instantiation
'boost::archive::detail::save_non_pointer_type<Archive,T>::save_only'
being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(23
7) : while compiling class-template member function 'void
boost::archive::detail::save_non_pointer_type<Archive,T>::invoke(Archive
&,const T &)'
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(55
1) : see reference to class template instantiation
'boost::archive::detail::save_non_pointer_type<Archive,T>' being
compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\basic_text_oarchive.hpp(7
1) : see reference to function template instantiation 'void
boost::archive::save<Archive,T>(Archive &,const T &)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive
.hpp(87) : see reference to function template instantiation 'void
boost::archive::basic_text_oarchive<Archive>::save_override<T>(const T
&,int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=boost::serialization::nvp<char *>
        ]
        c:\Proj\lnp\core\test\sertest.cpp(14) : see reference to
function template instantiation 'Archive
&boost::archive::detail::interface_oarchive<Archive>::operator
&<boost::serialization::nvp<T>>(const boost::serialization::nvp<T> &)'
being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=char *
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\access.hpp(106) :
see reference to function template instantiation 'void
test<T>::serialize<Archive>(Archive &,const unsigned int)' being
compiled
        with
        [
            T=char,
            Archive=boost::archive::text_oarchive
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(7
8) : see reference to function template instantiation 'void
boost::serialization::access::serialize<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(1
21) : see reference to function template instantiation 'void
boost::serialization::serialize<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(15
2) : see reference to function template instantiation 'void
boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const
unsigned int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\serialization\extended_type_info_
typeid.hpp(100) : while compiling class-template member function 'void
boost::archive::detail::oserializer<Archive,T>::save_object_data(boost::
archive::detail::basic_oarchive &,const void *) const'
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(23
4) : see reference to class template instantiation
'boost::archive::detail::oserializer<Archive,T>' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(23
3) : while compiling class-template member function 'void
boost::archive::detail::save_non_pointer_type<Archive,T>::save::invokex(
Archive &,const T &)'
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(30
9) : see reference to class template instantiation
'boost::archive::detail::save_non_pointer_type<Archive,T>::save' being
compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(23
7) : while compiling class-template member function 'void
boost::archive::detail::save_non_pointer_type<Archive,T>::invoke(Archive
&,const T &)'
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(55
1) : see reference to class template instantiation
'boost::archive::detail::save_non_pointer_type<Archive,T>' being
compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\basic_text_oarchive.hpp(7
1) : see reference to function template instantiation 'void
boost::archive::save<Archive,T>(Archive &,const T &)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive
.hpp(80) : see reference to function template instantiation 'void
boost::archive::basic_text_oarchive<Archive>::save_override<T>(const T
&,int)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=test<char>
        ]
c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive
.hpp(105) : see reference to function template instantiation 'Archive
&boost::archive::detail::interface_oarchive<Archive>::operator
<<<test<T>>(const test<T> &)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=char
        ]
        c:\Proj\lnp\core\test\sertest.cpp(55) : see reference to
function template instantiation 'Archive
&boost::archive::detail::interface_oarchive<Archive>::operator
<<<test<T>>(test<T> &)' being compiled
        with
        [
            Archive=boost::archive::text_oarchive,
            T=char
        ]
test - 1 error(s), 0 warning(s)
---------------------- Done ----------------------
Build: 0 succeeded, 1 failed, 0 skipped