Passing a bitsery buffer to a C API

[VelocityRa]

I want to pass some serialized state to a C API, but I don't really see a way of doing that without an additional copy.
By "additional copy" I mean, currently I am using a std::vector BufferWriter. The std::vector will be destroyed after my C API call returns because of RAII. I can't stop that. So I have to use malloc + copy that data somewhere else, which is wasteful.

To be clear, I am the developer of that C API. I want to expose "load" and "save" functions for some state.
So perhaps I could use an opaque pointer that holds a newed std::vector? But that sounds hacky.
Maybe there's a solution where OutputBufferAdapter can be implemented to use malloc + realloc.

Excuse my quick + maybe unclear problem description.
Also if this is not currently feasible, I understand.

Thanks.

[fraillt]

If I understood your problem correctly, you can use C-style array or even pointer+size as a buffer. Here is specializations provided for both cases. Also you could look at working example here

[VelocityRa]

Right, but that example is for a C static array and for the other one, I don't know the total size of the serialized data that will be saved ahead of time.
I have lots of objects serialized recursively and some are dynamic.
I don't see a specialization there that would allow for that use-case I think.

For example, a possible solution would be to give bitsery a malloced buffer of some initial size, and then it would realloc as it needs space (just as it does .push_back for std::vector OutputBufferAdapters). Or just give it a ** and it would malloc too and put the pointer there.

Hopefully I explained the problem more clearly now.

[fraillt]

You left with only one solution then. You will need to provide a custom buffer implementation and specialize it for ContainerTraits and BufferAdapterTraits. Hope that helped:)

[VelocityRa]

Ok I see, thank you.