Serializing Boost.Tuple
Hi, Just thought I would share some code that serializes Boost.Tuple using Boost.Serialization: #include <boost/tuple/tuple.hpp> #include <boost/serialization/nvp.hpp> #include <boost/preprocessor/repetition.hpp> namespace boost { namespace serialization { #define GENERATE_ELEMENT_SERIALIZE(z,which,unused) \ ar & boost::serialization::make_nvp("element",t.get< which >()); #define GENERATE_TUPLE_SERIALIZE(z,nargs,unused) \ template< typename Archive, BOOST_PP_ENUM_PARAMS(nargs,typename T) > \ void serialize(Archive & ar, \ boost::tuple< BOOST_PP_ENUM_PARAMS(nargs,T) > & t, \ const unsigned int version) \ { \ BOOST_PP_REPEAT_FROM_TO(0,nargs,GENERATE_ELEMENT_SERIALIZE,~) \ } BOOST_PP_REPEAT_FROM_TO(1,10,GENERATE_TUPLE_SERIALIZE,~); }} It does not handle 0-element tuples (not sure that it should, actually!) Kudos to the insanity that produced Boost.Preprocessor. -- Sohail Somani http://uint32t.blogspot.com
On Thu, 27 Mar 2008 15:27:46 -0300, Felipe Magno de Almeida wrote:
Is there any plan to include this code to a tuple header? tuple_serialization.hpp ?
I think the best way to get it looked at would be to file a bug. Anyway, if there was an is_tuple<T> metafunction, there would be a more elegant way to do it: // not compiled or tested namespace boost { namespace serialization { template<typename TupleType, int Which> struct serialize { template<typename Archive> static void call(Archive & ar, TupleType & t) { ar & t.get<Which>(); serialize<TupleType,Which-1>::call(ar,t); } }; template<typename TupleType> struct serialize<TupleType,0> { template<typename Archive> static void call(Archive & ar, TupleType & t) { ar & t.get<0>(); } }; template<typename Archive, typename TupleType> typename boost::enable_if<is_tuple<TupleType>::value,void>::type void serialize(Archive & ar, TupleType & t, int fv) { return serialize<TupleType,TupleType::size-1>::call(ar,t); } }} -- Sohail Somani http://uint32t.blogspot.com
On Thu, 27 Mar 2008 19:00:34 +0000, Sohail Somani wrote:
Hmm, no I lied. You couldn't do it this way because then the overload would be ambiguous when it matched. I think... -- Sohail Somani http://uint32t.blogspot.com
On Thu, 27 Mar 2008 16:32:25 -0300, Felipe Magno de Almeida wrote:
Ambiguous with the other boost::serialization::serialize function. I was thinking of: template<typename Archive, typename TupleType> boost::enable_if<is_tuple<TupleType>::value,void>::type serialize(Archive & ar, TupleType & t, const unsigned int); But the function that gets called when anything is serialized is: template<typename Archive, typename T> void serialize(Archive & ar, T & t, const unsigned int); So when is_tuple<TupleType>::value is true, then there are two functions which match the required signature => ambiguous. Atleast in my head anyway. Anyway, the Boost.PP version is fine :-) -- Sohail Somani http://uint32t.blogspot.com
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Sohail Somani