[Boost-users] serialization: pointer reconstruction

Subject: [Boost-users] serialization: pointer reconstruction
From: Noah Roberts (roberts.noah_at_[hidden])
Date: 2010-01-26 12:24:47

A while back I asked about saving a pointer to an item in another class 
that is stored as a direct instance variable (no pointer).  Here's a 
brief illustration:

struct A
{
};

struct B
{
  A a;
};

struct C
{
  A * a; // points to a B::a.
};

I have an idea how to store and restore these relationships but I'd like 
to see if there are any improvement ideas and/or direction to existing 
behavior I'm not seeing in the documentation.

My idea is to first store B::a (which simply makes sense in my problem 
anyway) and when I do this to call some custom support functions to 
generate a unique ID for the object at that address and store it first, 
then the rest of the data in A.  This would appear in A::serialize and 
the unique ID would be stored in the Archive (added behavior) as a map 
from address to uid.

Then when storing C I would request the unique ID for the address the 
pointer stores and store it.

On reading I read B::a first and it sort of reverses the process.  The 
uid is read and then A::serialize stores the uid and 'this' in the 
archive map in a uid->address format.  I then read the uid on reading 
C::a and request the address from the archive using that value.

I've already subclassed the Archive in order to pass around other load 
information needed by classes that didn't have local copies, so that's 
the easy part (though it wasn't a straight forward operation).  The 
question I have though is that since the pointer archiving already must 
use some similar type of API, can I use it instead of rolling my own and 
how would I do that?