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_DETAIL_HETEROGENEOUS_CONVERSION_HPP
Chris@16: #define BOOST_UNITS_DETAIL_HETEROGENEOUS_CONVERSION_HPP
Chris@16: 
Chris@16: #include <boost/mpl/minus.hpp>
Chris@16: #include <boost/mpl/times.hpp>
Chris@16: 
Chris@16: #include <boost/units/static_rational.hpp>
Chris@16: #include <boost/units/homogeneous_system.hpp>
Chris@16: #include <boost/units/detail/linear_algebra.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: namespace units {
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: struct solve_end {
Chris@16:     template<class Begin, class Y>
Chris@16:     struct apply {
Chris@16:         typedef dimensionless_type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: struct no_solution {};
Chris@16: 
Chris@16: template<class X1, class X2, class Next>
Chris@16: struct solve_normal {
Chris@16:     template<class Begin, class Y>
Chris@16:     struct apply {
Chris@16:         typedef typename Begin::next next;
Chris@16:         typedef list<
Chris@16:             typename mpl::minus<
Chris@16:                 typename mpl::times<X1, Y>::type,
Chris@16:                 typename mpl::times<X2, typename Begin::item>::type
Chris@16:             >::type,
Chris@16:             typename Next::template apply<next, Y>::type
Chris@16:         > type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<class Next>
Chris@16: struct solve_leading_zeroes {
Chris@16:     template<class Begin>
Chris@16:     struct apply {
Chris@16:         typedef list<
Chris@16:             typename Begin::item,
Chris@16:             typename Next::template apply<typename Begin::next>::type
Chris@16:         > type;
Chris@16:     };
Chris@16:     typedef solve_leading_zeroes type;
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct solve_leading_zeroes<no_solution> {
Chris@16:     typedef no_solution type;
Chris@16: };
Chris@16: 
Chris@16: template<class Next>
Chris@16: struct solve_first_non_zero {
Chris@16:     template<class Begin>
Chris@16:     struct apply {
Chris@16:         typedef typename Next::template apply<
Chris@16:             typename Begin::next,
Chris@16:             typename Begin::item
Chris@16:         >::type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<class Next>
Chris@16: struct solve_internal_zero {
Chris@16:     template<class Begin, class Y>
Chris@16:     struct apply {
Chris@16:         typedef list<
Chris@16:             typename Begin::item,
Chris@16:             typename Next::template apply<typename Begin::next, Y>::type
Chris@16:         > type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<class T>
Chris@16: struct make_solve_list_internal_zero {
Chris@16:     template<class Next, class X>
Chris@16:     struct apply {
Chris@16:         typedef solve_normal<T, X, Next> type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct make_solve_list_internal_zero<static_rational<0> > {
Chris@16:     template<class Next, class X>
Chris@16:     struct apply {
Chris@16:         typedef solve_internal_zero<Next> type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<int N>
Chris@16: struct make_solve_list_normal {
Chris@16:     template<class Begin, class X>
Chris@16:     struct apply {
Chris@16:         typedef typename make_solve_list_internal_zero<
Chris@16:             typename Begin::item
Chris@16:         >::template apply<
Chris@16:             typename make_solve_list_normal<N-1>::template apply<typename Begin::next, X>::type,
Chris@16:             X
Chris@16:         >::type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct make_solve_list_normal<0> {
Chris@16:     template<class Begin, class X>
Chris@16:     struct apply {
Chris@16:         typedef solve_end type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<int N>
Chris@16: struct make_solve_list_leading_zeroes;
Chris@16: 
Chris@16: template<class T>
Chris@16: struct make_solve_list_first_non_zero {
Chris@16:     template<class Begin, int N>
Chris@16:     struct apply {
Chris@16:         typedef solve_first_non_zero<
Chris@16:             typename make_solve_list_normal<N-1>::template apply<
Chris@16:                 typename Begin::next,
Chris@16:                 typename Begin::item
Chris@16:             >::type
Chris@16:         > type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct make_solve_list_first_non_zero<static_rational<0> > {
Chris@16:     template<class Begin, int N>
Chris@16:     struct apply {
Chris@16:         typedef typename solve_leading_zeroes<
Chris@16:             typename make_solve_list_leading_zeroes<N-1>::template apply<
Chris@16:                 typename Begin::next
Chris@16:             >::type
Chris@16:         >::type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<int N>
Chris@16: struct make_solve_list_leading_zeroes {
Chris@16:     template<class Begin>
Chris@16:     struct apply {
Chris@16:         typedef typename make_solve_list_first_non_zero<typename Begin::item>::template apply<Begin, N>::type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct make_solve_list_leading_zeroes<0> {
Chris@16:     template<class Begin>
Chris@16:     struct apply {
Chris@16:         typedef no_solution type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<int N>
Chris@16: struct try_add_unit_impl {
Chris@16:     template<class Begin, class L>
Chris@16:     struct apply {
Chris@16:         typedef typename try_add_unit_impl<N-1>::template apply<typename Begin::next, L>::type next;
Chris@16:         typedef typename Begin::item::template apply<next>::type type;
Chris@16:         BOOST_STATIC_ASSERT((next::size::value - 1 == type::size::value));
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct try_add_unit_impl<0> {
Chris@16:     template<class Begin, class L>
Chris@16:     struct apply {
Chris@16:         typedef L type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<int N>
Chris@16: struct make_homogeneous_system_impl;
Chris@16: 
Chris@16: template<class T, bool is_done>
Chris@16: struct make_homogeneous_system_func;
Chris@16: 
Chris@16: template<class T>
Chris@16: struct make_homogeneous_system_func<T, false> {
Chris@16:     template<class Begin, class Current, class Units, class Dimensions, int N>
Chris@16:     struct apply {
Chris@16:         typedef typename make_homogeneous_system_impl<N-1>::template apply<
Chris@16:             typename Begin::next,
Chris@16:             list<T, Current>,
Chris@16:             list<typename Begin::item, Units>,
Chris@16:             Dimensions
Chris@16:         >::type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<class T>
Chris@16: struct make_homogeneous_system_func<T, true> {
Chris@16:     template<class Begin, class Current, class Units, class Dimensions, int N>
Chris@16:     struct apply {
Chris@16:         typedef list<typename Begin::item, Units> type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct make_homogeneous_system_func<no_solution, false> {
Chris@16:     template<class Begin, class Current, class Units, class Dimensions, int N>
Chris@16:     struct apply {
Chris@16:         typedef typename make_homogeneous_system_impl<N-1>::template apply<
Chris@16:             typename Begin::next,
Chris@16:             Current,
Chris@16:             Units,
Chris@16:             Dimensions
Chris@16:         >::type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct make_homogeneous_system_func<no_solution, true> {
Chris@16:     template<class Begin, class Current, class Units, class Dimensions, int N>
Chris@16:     struct apply {
Chris@16:         typedef typename make_homogeneous_system_impl<N-1>::template apply<
Chris@16:             typename Begin::next,
Chris@16:             Current,
Chris@16:             Units,
Chris@16:             Dimensions
Chris@16:         >::type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<int N>
Chris@16: struct make_homogeneous_system_impl {
Chris@16:     template<class Begin, class Current, class Units, class Dimensions>
Chris@16:     struct apply {
Chris@16:         typedef typename expand_dimensions<Dimensions::size::value>::template apply<
Chris@16:             Dimensions,
Chris@16:             typename Begin::item::dimension_type
Chris@16:         >::type dimensions;
Chris@16:         typedef typename try_add_unit_impl<Current::size::value>::template apply<Current, dimensions>::type new_element;
Chris@16:         typedef typename make_solve_list_leading_zeroes<new_element::size::value>::template apply<new_element>::type new_func;
Chris@16:         typedef typename make_homogeneous_system_func<
Chris@16:             new_func,
Chris@16:             ((Current::size::value)+1) == (Dimensions::size::value)
Chris@16:         >::template apply<Begin, Current, Units, Dimensions, N>::type type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct make_homogeneous_system_impl<0> {
Chris@16:     template<class Begin, class Current, class Units, class Dimensions>
Chris@16:     struct apply {
Chris@16:         typedef Units type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<class Units>
Chris@16: struct make_homogeneous_system {
Chris@16:     typedef typename find_base_dimensions<Units>::type base_dimensions;
Chris@16:     typedef homogeneous_system<
Chris@16:         typename insertion_sort<
Chris@16:             typename make_homogeneous_system_impl<
Chris@16:                 Units::size::value
Chris@16:             >::template apply<
Chris@16:                 Units,
Chris@16:                 dimensionless_type,
Chris@16:                 dimensionless_type,
Chris@16:                 base_dimensions
Chris@16:             >::type
Chris@16:         >::type
Chris@16:     > type;
Chris@16: };
Chris@16: 
Chris@16: template<int N>
Chris@16: struct extract_base_units {
Chris@16:     template<class Begin, class T>
Chris@16:     struct apply {
Chris@16:         typedef list<
Chris@16:             typename Begin::item::tag_type,
Chris@16:             typename extract_base_units<N-1>::template apply<typename Begin::next, T>::type
Chris@16:         > type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct extract_base_units<0> {
Chris@16:     template<class Begin, class T>
Chris@16:     struct apply {
Chris@16:         typedef T type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: #endif