Re: [Boost-users] cross-platfrom binary serialization?

From: Robert Ramey (ramey_at_[hidden])
Date: 2008-08-29 16:40:09

Just to keep the pot boiling - here's my two cents.

a) Basically, floats can be represent as two integers.
One for the exponent and one for a normalized fraction
of one.

b) The C standard library provides functions which
generate these two integers from any double (frexp)
and retrieves the origninal double from the pair
of integers(ldexp).  I would guess that these functions
are pretty efficient as they only return a subset of
some existing bits.

c) the portable binary archive currently in the libraries
handles integers in a portable manner.  It has been
tested on various platforms and already addresses
issues such as what to do when on attempts to load
an integer > 2^32 to a 32 bit machine.  It also
strips leading bits which don't add anything and makes
the archives smaller.

It would seem using the standard functions - supported
by any standard C library - and using the functionality
already in portable_binary_archive, one could add
floating point functionality relatively easily - and it
would be no less portable than the C library is.

Robert Ramey