boost/units/make_system.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) 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_MAKE_SYSTEM_HPP
  12 #define BOOST_UNITS_MAKE_SYSTEM_HPP
  13
  14 #include <boost/units/config.hpp>
  15 #include <boost/units/dimensionless_type.hpp>
  16 #include <boost/units/homogeneous_system.hpp>
  17 #include <boost/units/detail/dimension_list.hpp>
  18 #include <boost/units/detail/sort.hpp>
  19
  20 namespace boost {
  21
  22 namespace units {
  23
  24 #ifdef BOOST_UNITS_DOXYGEN
  25
  26 namespace detail {
  27
  28 struct unspecified {};
  29
  30 }
  31
  32 /// Metafunction returning a homogeneous system that can
  33 /// represent any combination of the base units.  There must
  34 /// be no way to represent any of the base units in terms
  35 /// of the others.  make_system<foot_base_unit, meter_base_unit>::type
  36 /// is not allowed, for example.
  37 template<class BaseUnit0, class BaseUnit1, class BaseUnit2, ..., class BaseUnitN>
  38 struct make_system
  39 {
  40     typedef homogeneous_system<detail::unspecified> type;
  41 };
  42
  43 #else
  44
  45 struct na {};
  46
  47 template<
  48     class U0 = na,
  49     class U1 = na,
  50     class U2 = na,
  51     class U3 = na,
  52     class U4 = na,
  53     class U5 = na,
  54     class U6 = na,
  55     class U7 = na,
  56     class U8 = na,
  57     class U9 = na
  58 >
  59 struct make_system;
  60
  61 template<>
  62 struct make_system<>
  63 {
  64     typedef homogeneous_system<dimensionless_type> type;
  65 };
  66
  67 // Codewarrior 9.2 doesn't like using the defaults.  Need
  68 // to specify na explicitly.
  69 template<class T0>
  70 struct make_system<T0, na, na, na, na, na, na, na, na, na>
  71 {
  72     typedef homogeneous_system<list<T0, dimensionless_type> > type;
  73 };
  74
  75 template<class T0, class T1>
  76 struct make_system<T0, T1, na, na, na, na, na, na, na, na>
  77 {
  78     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, dimensionless_type> > >::type> type;
  79 };
  80
  81 template<class T0, class T1, class T2>
  82 struct make_system<T0, T1, T2, na, na, na, na, na, na, na>
  83 {
  84     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, list<T2, dimensionless_type> > > >::type> type;
  85 };
  86
  87 template<class T0, class T1, class T2, class T3>
  88 struct make_system<T0, T1, T2, T3, na, na, na, na, na, na>
  89 {
  90     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, list<T2, list<T3, dimensionless_type> > > > >::type> type;
  91 };
  92
  93 template<class T0, class T1, class T2, class T3, class T4>
  94 struct make_system<T0, T1, T2, T3, T4, na, na, na, na, na>
  95 {
  96     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, list<T2, list<T3, list<T4, dimensionless_type> > > > > >::type> type;
  97 };
  98
  99 template<class T0, class T1, class T2, class T3, class T4, class T5>
 100 struct make_system<T0, T1, T2, T3, T4, T5, na, na, na, na>
 101 {
 102     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, list<T2, list<T3, list<T4, list<T5, dimensionless_type> > > > > > >::type> type;
 103 };
 104
 105 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6>
 106 struct make_system<T0, T1, T2, T3, T4, T5, T6, na, na, na>
 107 {
 108     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, list<T2, list<T3, list<T4, list<T5, list<T6, dimensionless_type> > > > > > > >::type> type;
 109 };
 110
 111 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6, class T7>
 112 struct make_system<T0, T1, T2, T3, T4, T5, T6, T7, na, na>
 113 {
 114     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, list<T2, list<T3, list<T4, list<T5, list<T6, list<T7, dimensionless_type> > > > > > > > >::type> type;
 115 };
 116
 117 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8>
 118 struct make_system<T0, T1, T2, T3, T4, T5, T6, T7, T8, na>
 119 {
 120     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, list<T2, list<T3, list<T4, list<T5, list<T6, list<T7, list<T8, dimensionless_type> > > > > > > > > >::type> type;
 121 };
 122
 123 template<class T0, class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9>
 124 struct make_system
 125 {
 126     typedef homogeneous_system<typename detail::insertion_sort<list<T0, list<T1, list<T2, list<T3, list<T4, list<T5, list<T6, list<T7, list<T8, list<T9, dimensionless_type> > > > > > > > > > >::type> type;
 127 };
 128
 129 #endif
 130
 131 } // namespace units
 132
 133 } // namespace boost
 134
 135 #endif