Chris@16: // Boost.Units - A C++ library for zero-overhead dimensional analysis and 
Chris@16: // unit/quantity manipulation and conversion
Chris@16: //
Chris@16: // Copyright (C) 2003-2008 Matthias Christian Schabel
Chris@16: // Copyright (C) 2008 Steven Watanabe
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_UNITS_ABSOLUTE_IMPL_HPP
Chris@16: #define BOOST_UNITS_ABSOLUTE_IMPL_HPP
Chris@16: 
Chris@16: #include <iosfwd>
Chris@16: 
Chris@16: #include <boost/units/config.hpp>
Chris@16: #include <boost/units/conversion.hpp>
Chris@16: #include <boost/units/heterogeneous_system.hpp>
Chris@16: #include <boost/units/units_fwd.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: namespace units {
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: template<class D, class S>
Chris@16: struct reduce_unit<absolute<unit<D, S> > >
Chris@16: {
Chris@16:     typedef absolute<typename reduce_unit<unit<D, S> >::type> type;
Chris@16: };
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: struct undefined_affine_conversion_base {
Chris@16:     static const bool is_defined = false;
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: template<class From, class To>
Chris@16: struct affine_conversion_helper : detail::undefined_affine_conversion_base { };
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: template<bool IsDefined, bool ReverseIsDefined>
Chris@16: struct affine_conversion_impl;
Chris@16: 
Chris@16: template<bool ReverseIsDefined>
Chris@16: struct affine_conversion_impl<true, ReverseIsDefined>
Chris@16: {
Chris@16:     template<class Unit1, class Unit2, class T0, class T1>
Chris@16:     struct apply {
Chris@16:         static T1 value(const T0& t0)
Chris@16:         {
Chris@16:             return(
Chris@16:                 t0 * 
Chris@16:                 conversion_factor(Unit1(), Unit2()) +
Chris@16:                 affine_conversion_helper<typename reduce_unit<Unit1>::type, typename reduce_unit<Unit2>::type>::value());
Chris@16:         }
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct affine_conversion_impl<false, true>
Chris@16: {
Chris@16:     template<class Unit1, class Unit2, class T0, class T1>
Chris@16:     struct apply
Chris@16:     {
Chris@16:         static T1 value(const T0& t0)
Chris@16:         {
Chris@16:             return(
Chris@16:                 (t0 - affine_conversion_helper<typename reduce_unit<Unit2>::type, typename reduce_unit<Unit1>::type>::value()) * 
Chris@16:                 conversion_factor(Unit1(), Unit2()));
Chris@16:         }
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: template<class Unit1, class T1, class Unit2, class T2>
Chris@16: struct conversion_helper<quantity<absolute<Unit1>, T1>, quantity<absolute<Unit2>, T2> >
Chris@16: {
Chris@16:     typedef quantity<absolute<Unit1>, T1> from_quantity_type;
Chris@16:     typedef quantity<absolute<Unit2>, T2> to_quantity_type;
Chris@16:     static to_quantity_type convert(const from_quantity_type& source)
Chris@16:     {
Chris@16:         return(
Chris@16:             to_quantity_type::from_value(
Chris@16:                 detail::affine_conversion_impl<
Chris@16:                     affine_conversion_helper<typename reduce_unit<Unit1>::type, typename reduce_unit<Unit2>::type>::is_defined,
Chris@16:                     affine_conversion_helper<typename reduce_unit<Unit2>::type, typename reduce_unit<Unit1>::type>::is_defined
Chris@16:                 >::template apply<Unit1, Unit2, T1, T2>::value(source.value())
Chris@16:             )
Chris@16:         );
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: } // namespace units
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_UNITS_ABSOLUTE_IMPL_HPP