ceph/src/boost/libs/units/include/boost/units/detail/absolute_impl.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_ABSOLUTE_IMPL_HPP
  12 #define BOOST_UNITS_ABSOLUTE_IMPL_HPP
  13
  14 #include <iosfwd>
  15
  16 #include <boost/units/config.hpp>
  17 #include <boost/units/conversion.hpp>
  18 #include <boost/units/heterogeneous_system.hpp>
  19 #include <boost/units/units_fwd.hpp>
  20
  21 namespace boost {
  22
  23 namespace units {
  24
  25 /// INTERNAL ONLY
  26 template<class D, class S>
  27 struct reduce_unit<absolute<unit<D, S> > >
  28 {
  29     typedef absolute<typename reduce_unit<unit<D, S> >::type> type;
  30 };
  31
  32 namespace detail {
  33
  34 struct undefined_affine_conversion_base {
  35     static const bool is_defined = false;
  36 };
  37
  38 } // namespace detail
  39
  40 /// INTERNAL ONLY
  41 template<class From, class To>
  42 struct affine_conversion_helper : detail::undefined_affine_conversion_base { };
  43
  44 namespace detail {
  45
  46 template<bool IsDefined, bool ReverseIsDefined>
  47 struct affine_conversion_impl;
  48
  49 template<bool ReverseIsDefined>
  50 struct affine_conversion_impl<true, ReverseIsDefined>
  51 {
  52     template<class Unit1, class Unit2, class T0, class T1>
  53     struct apply {
  54         static T1 value(const T0& t0)
  55         {
  56             return(
  57                 t0 *
  58                 conversion_factor(Unit1(), Unit2()) +
  59                 affine_conversion_helper<typename reduce_unit<Unit1>::type, typename reduce_unit<Unit2>::type>::value());
  60         }
  61     };
  62 };
  63
  64 template<>
  65 struct affine_conversion_impl<false, true>
  66 {
  67     template<class Unit1, class Unit2, class T0, class T1>
  68     struct apply
  69     {
  70         static T1 value(const T0& t0)
  71         {
  72             return(
  73                 (t0 - affine_conversion_helper<typename reduce_unit<Unit2>::type, typename reduce_unit<Unit1>::type>::value()) *
  74                 conversion_factor(Unit1(), Unit2()));
  75         }
  76     };
  77 };
  78
  79 } // namespace detail
  80
  81 /// INTERNAL ONLY
  82 template<class Unit1, class T1, class Unit2, class T2>
  83 struct conversion_helper<quantity<absolute<Unit1>, T1>, quantity<absolute<Unit2>, T2> >
  84 {
  85     typedef quantity<absolute<Unit1>, T1> from_quantity_type;
  86     typedef quantity<absolute<Unit2>, T2> to_quantity_type;
  87     static to_quantity_type convert(const from_quantity_type& source)
  88     {
  89         return(
  90             to_quantity_type::from_value(
  91                 detail::affine_conversion_impl<
  92                     affine_conversion_helper<typename reduce_unit<Unit1>::type, typename reduce_unit<Unit2>::type>::is_defined,
  93                     affine_conversion_helper<typename reduce_unit<Unit2>::type, typename reduce_unit<Unit1>::type>::is_defined
  94                 >::template apply<Unit1, Unit2, T1, T2>::value(source.value())
  95             )
  96         );
  97     }
  98 };
  99
 100 } // namespace units
 101
 102 } // namespace boost
 103
 104 #endif // BOOST_UNITS_ABSOLUTE_IMPL_HPP