Robert Ramey wrote:

...

binary_oarchive oa(...); Data data(....); oa << data;

...

Now, how do I deserialize it? I can't write

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Data data; ia >> data;

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Since ctor is private. I would guess it's still possible to deserialize this class, but I don't know how.

what's the matter with

Data data(....); ia >> data;

The wrong is that when I create and serialize data, I have something to pass as ctor parameter. But when deserializing, I don't have that something. Let's be more specific: the ctor parameter includes parse tree. I can't serialize it because it requires *lots* of work.

I don't see how the fact you want to construct different ways is related serialization. Unless its a pointer, serialization presumes the instance has already been constructed. How this is done is outside the influence of the serialization library.

What I'm after it telling to serialization lib: "hey, I know this data was not serialized via pointer, but I want to restore it into pointer variable, so that serialization lib creates it itself". Specifically, I look at this code from collection_load_imp.hpp: stack_allocate<type> t;^M load_construct_data(ar, t.address(), 0U);^M ar >> make_nvp("item", t.reference());^M Can the same trick be use from user code? I'm not all all sure it's better than saving Data as pointer in the first place, but I'm exploring possibilities. - Volodya