ceph/src/boost/libs/units/include/boost/units/detail/dimensionless_unit.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_DIMENSIONLESS_UNIT_HPP
  12 #define BOOST_UNITS_DETAIL_DIMENSIONLESS_UNIT_HPP
  13
  14 #include <boost/mpl/bool.hpp>
  15 #include <boost/units/units_fwd.hpp>
  16
  17 namespace boost {
  18 namespace units {
  19
  20 template<class T>
  21 struct heterogeneous_system;
  22
  23 template<class T>
  24 struct homogeneous_system;
  25
  26 template<class T1, class T2, class Scale>
  27 struct heterogeneous_system_impl;
  28
  29 typedef boost::units::heterogeneous_system<
  30     boost::units::heterogeneous_system_impl<
  31         boost::units::dimensionless_type,
  32         boost::units::dimensionless_type,
  33         boost::units::dimensionless_type
  34     >
  35 > heterogeneous_dimensionless_system;
  36
  37 namespace detail {
  38
  39 template<class System>
  40 struct void_if_dimensionless {
  41     typedef int type;
  42 };
  43
  44 template<class T>
  45 struct void_if_dimensionless<boost::units::homogeneous_system<T> > {
  46     typedef void type;
  47 };
  48
  49 template<>
  50 struct void_if_dimensionless<heterogeneous_dimensionless_system> {
  51     typedef void type;
  52 };
  53
  54 template<class System, class Test = void>
  55 struct void_if_heterogeneous {
  56     typedef void type;
  57 };
  58
  59 template<class System>
  60 struct void_if_heterogeneous<System, typename void_if_dimensionless<System>::type> {
  61     typedef int type;
  62 };
  63
  64 template<class System, class Enable=void>
  65 struct is_dimensionless_system : mpl::false_ {};
  66
  67 template<class System>
  68 struct is_dimensionless_system<System, typename void_if_dimensionless<System>::type> : mpl::true_ {};
  69
  70 #define BOOST_UNITS_DIMENSIONLESS_UNIT(T)\
  71     boost::units::unit<\
  72         boost::units::dimensionless_type,\
  73         T,\
  74         typename ::boost::units::detail::void_if_dimensionless<T>::type\
  75     >
  76
  77 #define BOOST_UNITS_HETEROGENEOUS_DIMENSIONLESS_UNIT(T)\
  78     boost::units::unit<\
  79         boost::units::dimensionless_type,\
  80         T,\
  81         typename ::boost::units::detail::void_if_heterogeneous<T>::type\
  82     >
  83
  84 }
  85 }
  86 }
  87
  88 #endif