[boost] [rational] Over/underflow checked update ready for comments

25 Aug 2012

      For those interested in rational, there is an updated version
in https://svn.boost.org/svn/boost/sandbox/rational ready
for comments.

Quick overview of the update: the original usage and
code of the template class remains mostly as before, ie
boost::rational<int> RationalVar; should work as
in the original version. Adding 'true' as a second
template parameter, however, allows an exception to
be raised if an operation with a class variable results
in a value that can't accurately be represented, ie
boost::rational<int,true> RationalVarChecked.
Checking is only needed on limited precision integer
types, and it has been tested with signed char, short, int
and long long.

Thank you for your constructive comments.

Dan Searles