TODO list for the Interval Arithmetic library
  Comments from the review process
  
    - It would be nice to have a 100% portable Rounding policy class based
    on LIA-1 only, with no additional requirement such as IEEE 754 or even
    more.
- For pi and other constants, we should fetch them from the Math
    constants library when it is ready.
Various items
  
    - Support the -mfpmath=sseoption of g++ for Pentium IV
    optimized code. This requires a different rounding policy class.
- Have an optimized specialization of
    interval<double>using SSE2 instructions? Tricky.
- Write a traits specialization for interval<MPFR>,
    and other non-built-in number types.
- Have a robust implementation of transcendental functions over the
    built-in floating point types (e.g. using MPFR)?
- Safe conversions from interval<double>tointerval<float>? Requires partial specialization.
- It would be nice to use the expression template mechanism to
    automatically use the more efficient unprotected rounding mode version
    for small subexpressions (although you can do bigger expressions by
    hand).
  
  Revised 
  2006-12-24
  Copyright © 2002 Guillaume Melquiond, Sylvain Pion, Hervé
  Brönnimann, Polytechnic University
  Distributed under the Boost Software License, Version 1.0. (See
  accompanying file LICENSE_1_0.txt
  or copy at http://www.boost.org/LICENSE_1_0.txt)