-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi! Am 06.03.12 15:58, schrieb Allan Nielsen:
std::vector<int> data; std::vector<Bar> elements;
Foo() { // do very time consuming calculation to populate "data" and "elements" } };
Consider a change in design: make Foo default constructible and provide a static factory method to populate data and elements: struct Foo { ... Foo() {} // empty members static Foo createWithData() { Foo result; // do very time consuming calculation to // populate "data" and "elements" return result; // will move, not copy data in C++11 } }; The Foo(Archive&) approach will not scale well because I guess proper serialization of Foo will only be possible through a pointer (which implies the object will be constructed on the heap on deserialization.) For serialization through a pointer there is a way to use a non-default constructor as described here: http://www.boost.org/doc/libs/1_48_0/libs/serialization/doc/serialization.ht...
Here is what I have tried:
struct Foo { struct Bar { std::vector<int> * data;
Bar( ) : data( 0 ) { } Bar( std::vector<int> * d ) : data(d) { }
template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & data; // is this correct?
This looks good with the changes in Foo::serialize.
} };
std::vector<int> data; std::vector<Bar> elements;
Foo() { std::cerr << "Running default constructor" << std::endl; data.push_back(1); data.push_back(2); data.push_back(3); data.push_back(4); data.push_back(5); elements.push_back( Bar( &data ) ); elements.push_back( Bar( &data ) ); elements.push_back( Bar( &data ) ); }
template<class Archive> Foo( Archive & ar ) { ar >> data; // is this corrent?
It does not match the save operation: saving a pointer and loading a reference does not match. This is not correct.
ar >> elements; }
private: BOOST_SERIALIZATION_SPLIT_MEMBER(); friend class boost::serialization::access;
template<class Archive> void save(Archive & ar, const unsigned int version) const { const std::vector<int> * data_ptr = &data;
// should data be seriliazed as pointer... // it is used as a pointer in Bar ar << data_ptr; ar << elements; } };
My proposal: do not split into load/save, use the following instead: template<typename Archive> void serialize(Archive &ar, const unsigned int) { auto * data_ptr = &data; ar & data_ptr; // load and save through pointer if(Archive::is_loading::value) { data = std::move(*data_ptr); // no-throw ar.reset_object_address(&data, data_ptr); delete data_ptr; // not sure here } // load elements after reset_object_address() ar & elements; } The alternative is to make data a non-std type, like make a custom struct of it. Then you could just use ar & data & elements in combination with boost::serialization::track_always. http://www.boost.org/doc/libs/1_48_0/libs/serialization/doc/special.html#obj... HTH, Frank -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.17 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: keyserver x-hkp://pool.sks-keyservers.net iEYEARECAAYFAk9WhVEACgkQhAOUmAZhnmpFmACfRD1fVPfgrrkEYZpNlOzbi5VS 2EQAn0dHsN3U3FxV/9Wc0TMe2ESy5fWP =zdeg -----END PGP SIGNATURE-----