Sean Cavanaugh wrote:

Ok I've spent a good chunk of my day making a set of custom archive class, based on the portable_binary_iarchive and portable_binary_oarchive.

I have a non-virtual class hierarchy named Asset, in memory this is a cyclic graph, but my requirements are that this structure cannot be serialized all at once, it has to be broken up at boundaries. So the archiver serializes the first Asset* (which is always the root object passed into operator&). This object serializes as normally as per the boost serialization code, except except that when subsequent Asset*'s are encountered

?which point to a previously serialized object? or any subsequent Asset *?

I send the pointer into an AssetManager class and translate the Asset* into a ResourceID, and serialize the ResourceID instead of the object. This is done by directly calling operator& inside save_override.

******* Hmmm this sounds to me exactly equivalent to what the serialization system does by default for tracked objects. Objects serialized through pointers are tracked by default. Your "ResourceID" seems a re-implemenation of the "object id" used by the serialization libary to track

...

I also have to hard-code the full list of derived Asset types and manually provide specializations for all of them in save_override and load_override.

**** Well, since they're different - I would expect each of them to have a different serialize function. If all the serialize functions are the same, it would seem that something should be moved from the derived class to the base class.

If I use the base class, I end up slicing my class down to its base, and cannot serialize it.

**** serializing through a base class pointer solves this problem as well.

I can't make serialize virtual, since the intrusive serialize methods are templates, but it certainly would solve the problem if it were possible.

*** I suspect that if the other changes suggested were implemented this would disappear as a problem. I don't think I've tried it, but rather than including boiler plate code in each derived class, one might try adding a "mix-in" base class which contains the serialize function.

In addition the bodies of all of my overrides are completely identical except for the classname (AssetModel, AssetTexture, etc).

Which means I'll be wrapping the bodies of a generic save_override and load_override in a macro, and have to manually add all Asset derived classes to a list of classes inside my archive class. Which means that my archiver cannot be generic, even though I have managed to make it a template in the sense that the passed in asset manager and base asset types are template parameters.

*** looks to me that you've gotten off on the wrong foot and stuck with it.

the type ResourceID is a std::string

saving... class asset_oarchive : ... void save_override(const AssetModel& t, int i) { if (!RootAssetSaved) { RootAssetSaved = true; binary_oarchive_impl::save_override(t, i); } else { AssetManagerType::ResourceID ResourceId = TheAssetManager->ResourceIdForAsset(&t); operator&(ResourceId); } }

loading ... class asset_iarchive : ... void load_override(AssetModel*& t, int i) { if (!RootAssetLoaded) { RootAssetLoaded = true; binary_iarchive_impl::load_override(t, i); } else { unsigned char c[10]; for (INT x=0; x<10; ++x) { c[x] = 0xFF; } for (INT x=0; x<4; ++x) { operator&(c[x]); //hackhack } AssetManagerType::ResourceID ResourceId; operator&(ResourceId); AssetType* a = TheAssetManager->FindAsset(ResourceId); if (!a) { a = TheAssetManager->LoadAsset(ResourceId); } // TODO: throw on missing resources, potentially query asset manager for substitutes t = static_cast(a); } }

*** me this is exactly the wrong approach. Now you've coupled your classes to be serialized to a specific archive. This means you won't be able to use any other archive type and you've defeated one of the main benefits to the serialization library. Perhaps it wasn't a suitable library for your task. So I have a working implementation, how do I make it better? **** Maybe you might try doing it in the simplest way. I can't see how what you want to do is different than what everyone else uses the library for. And I can't see how what you want to do is different than what the examples do. Robert Ramey

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