Re: [Boost-users] Calculating needed space for Boost.Serialization

From: Robert Ramey (ramey_at_[hidden])
Date: 2008-06-23 12:42:12

You're making this way, way, way too hard.

All current archives are implemented in terms of standard library 
input/output.
Study the standard library.

You will find that you can make your own custom streambuf and
attach that to stream.  This is how stringstream is implemented.
Then instanticiate an archive using a stream with your custom
streambuf and serialize to that.  This is not hard to do and
would provide a universal solution for all archives.  Actually
I would expect a web search would turn up source code
for making a custom streambuf as this is the way the
standard library was designed to be used.

Of course if you're really lazy, you can just serialize
to a string stream, retrieve the size of the string
and throw it away.  But that's too lazy - even for me.

Robert Ramey

Oh - if you've got nothing else to do, you can make a streambuf
which does nothing but calcuates a CRC.  I would find that
useful.
RR

Ioannis Papadopoulos wrote:
> Hi,
>
> I want to calculate exactly how much space it is needed to serialize a
> number of objects. What I'm thinking is another class that implements
> the Saving Archive concept and only invokes sizeof() rather than
> actually writing anything.
>
> From what I understand I should overload the << and & operators for
> this class to call save() or serialize() on the object, unless it is a
> POD (in which case the size is already known).
>
> Has this been done before?
>
> Thanks