[Boost-users] [serialization] How should I lay down bits?

From: Daryle Walker (darylew_at_[hidden])
Date: 2008-06-27 15:20:39

My class contains an array of bits, currently expressed as  
boost::array<bool, 512>.  Will archives compact representations to  
multiple bits per serialized atom, or will they potentially waste a  
lot of space?

Regardless of the answer, I was thinking of compacting the data  
myself.  One way would be to compact the array into  
boost::array<unsigned char, CEIL(512 / CHAR_BIT)> and serialize  
that.  But I've wondered what happens between systems with differing  
CHAR_BIT values.  The solution I'm leaning towards is to create a  
text string like base-64 (pack every 6 bits together) and serialize  
that.  By the way, a bit stream may not use all 512 bits and I'm also  
tracking (and serializing) a length attribute.  I guess I should make  
sure that the length is serialized first.  How do I serialize an  
arbitrary text string?  How do I write the serialization routines  
knowing that one member (the bit array) is indirectly expressed (i.e.  
translate to/from the text string)?  I guess I need separate save &  
load methods at least.

-- 
Daryle Walker
Mac, Internet, and Video Game Junkie
darylew AT hotmail DOT com