Hi If I serialize a struct, while ignoring one of its members, the member retains its value. I understand that this is the inteded serialization semantics - what you ignore for reading and writing remains intact. However, if I do this with a vector, the ingored members of its elements get reset to their "default" values. I'm too lazy to pore over the sources, but I'm guessing this might be happening because the implementation of vector serialization calls its constructor (and assignment?) where a resize could probably be better. Here is the specific code I boiled down the manifestation of this feature/bug to: // creates writes "remove_me" file #include <iostream> #include <fstream> #include <vector> #include #include #include #include struct s { s() : i(0), j(0) {} s(int i, int j) : i(i), j(j) {} int i, j; private: friend class boost::serialization::access; template<typename Archive> void serialize(Archive& ar, const unsigned version) { // ignore j ar & i; } }; struct v { v(const s& x) : data(5, x) {} std::vector<s> data; void write(const char* name) const { std::ofstream out(name); boost::archive::text_oarchive ar(out); ar << *this; } void read(const char* name) { std::ifstream in(name); boost::archive::text_iarchive ar(in); ar >> *this; } private: friend class boost::serialization::access; template<typename Archive> void serialize(Archive& ar, const unsigned version) { ar & data; } }; int main() { using namespace std; const char name[] = "remove_me"; s si(1, 2); // j == 2 v vi(si); vi.write(name); vi.read(name); std::cout << vi.data[0].j << std::endl; // j == 0 }