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