boost/units/detail/ordinal.hpp

   1 // Boost.Units - A C++ library for zero-overhead dimensional analysis and
   2 // unit/quantity manipulation and conversion
   3 //
   4 // Copyright (C) 2003-2008 Matthias Christian Schabel
   5 // Copyright (C) 2007-2008 Steven Watanabe
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See
   8 // accompanying file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10
  11 #ifndef BOOST_UNITS_DETAIL_ORDINAL_HPP_INCLUDED
  12 #define BOOST_UNITS_DETAIL_ORDINAL_HPP_INCLUDED
  13
  14 #include <boost/mpl/less.hpp>
  15 #include <boost/mpl/bool.hpp>
  16
  17 namespace boost {
  18 namespace units {
  19
  20 namespace detail {
  21
  22 struct ordinal_tag {};
  23
  24 }
  25
  26 template<int N>
  27 struct ordinal {
  28     typedef detail::ordinal_tag tag;
  29     static const long value = N;
  30 };
  31
  32 template<int N>
  33 const long ordinal<N>::value;
  34
  35 }
  36
  37 namespace mpl {
  38
  39 template<>
  40 struct less_impl<units::detail::ordinal_tag, units::detail::ordinal_tag> {
  41     template<class T1, class T2>
  42     struct apply : bool_<(T1::value) < (T2::value)> {};
  43 };
  44
  45 }
  46
  47 }
  48
  49 #endif