Function add

gecode/third-party/boost/numeric/interval/arith3.hpp:25–33

namespace interval_lib {

template<class I> inline
I add(const typename I::base_type& x, const typename I::base_type& y)
{
  typedef typename I::traits_type Policies;
  if (detail::test_input<typename I::base_type, Policies>(x, y))
    return I::empty();
  typename Policies::rounding rnd;
  return I(rnd.add_down(x, y), rnd.add_up(x, y), true);
}

template<class I> inline
I sub(const typename I::base_type& x, const typename I::base_type& y)