[Boost-users] Serialization: how to inject context into save/load free functions?

Subject: [Boost-users] Serialization: how to inject context into save/load free functions?
From: Michael Schuerig (michael.lists_at_[hidden])
Date: 2011-06-15 09:34:28

I have a POD struct that I de/serialize through appropriately overloaded 
save and load free functions[*].

In my case, de/serialization involves translating between different 
representations (uid <-> username, gid <-> groupname). This translation 
is encapsulated in a class Etc and currently I just have a local 
variable of class Etc in both methods. I'd prefer a way to inject the 
Etc instance into save and load.

The ideal solution would meet these criteria:

* The Etc instance is created externally to save/load.
* No global or quasi-global (static or singleton) variables.
* No changes to the serialized struct (i.e. not an additional pointer to 
an Etc instance).
* Usable with existing archive classes without extension.

As far as I can tell, so far, I can't get all of these. I'm hoping that 
there is a way that I have overlooked.

Michael

[*] 
https://github.com/mschuerig/preserfs/blob/master/src/DirectoryMetadata.cpp#L146
-- 
Michael Schuerig
mailto:michael_at_[hidden]
http://www.schuerig.de/michael/