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