// 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_DIMENSION_IMPL_HPP | |
#define BOOST_UNITS_DIMENSION_IMPL_HPP | |
#include <boost/mpl/begin_end.hpp> | |
#include <boost/mpl/deref.hpp> | |
#include <boost/mpl/if.hpp> | |
#include <boost/mpl/list.hpp> | |
#include <boost/mpl/next.hpp> | |
#include <boost/mpl/size.hpp> | |
#include <boost/mpl/less.hpp> | |
#include <boost/units/config.hpp> | |
#include <boost/units/dimensionless_type.hpp> | |
#include <boost/units/static_rational.hpp> | |
#include <boost/units/units_fwd.hpp> | |
#include <boost/units/detail/dimension_list.hpp> | |
#include <boost/units/detail/push_front_if.hpp> | |
#include <boost/units/detail/push_front_or_add.hpp> | |
/// \file | |
/// \brief Core class and metaprogramming utilities for compile-time dimensional analysis. | |
namespace boost { | |
namespace units { | |
namespace detail { | |
template<int N> | |
struct insertion_sort_dims_insert; | |
template<bool is_greater> | |
struct insertion_sort_dims_comparison_impl; | |
// have to recursively add the element to the next sequence. | |
template<> | |
struct insertion_sort_dims_comparison_impl<true> { | |
template<class Begin, int N, class T> | |
struct apply { | |
typedef list< | |
typename Begin::item, | |
typename insertion_sort_dims_insert<N - 1>::template apply< | |
typename Begin::next, | |
T | |
>::type | |
> type; | |
}; | |
}; | |
// either prepend the current element or join it to | |
// the first remaining element of the sequence. | |
template<> | |
struct insertion_sort_dims_comparison_impl<false> { | |
template<class Begin, int N, class T> | |
struct apply { | |
typedef typename push_front_or_add<Begin, T>::type type; | |
}; | |
}; | |
template<int N> | |
struct insertion_sort_dims_insert { | |
template<class Begin, class T> | |
struct apply { | |
typedef typename insertion_sort_dims_comparison_impl<mpl::less<typename Begin::item, T>::value>::template apply< | |
Begin, | |
N, | |
T | |
>::type type; | |
}; | |
}; | |
template<> | |
struct insertion_sort_dims_insert<0> { | |
template<class Begin, class T> | |
struct apply { | |
typedef list<T, dimensionless_type> type; | |
}; | |
}; | |
template<int N> | |
struct insertion_sort_dims_mpl_sequence { | |
template<class Begin> | |
struct apply { | |
typedef typename insertion_sort_dims_mpl_sequence<N - 1>::template apply<typename mpl::next<Begin>::type>::type next; | |
typedef typename insertion_sort_dims_insert<(next::size::value)>::template apply<next, typename mpl::deref<Begin>::type>::type type; | |
}; | |
}; | |
template<> | |
struct insertion_sort_dims_mpl_sequence<0> { | |
template<class Begin> | |
struct apply { | |
typedef dimensionless_type type; | |
}; | |
}; | |
template<int N> | |
struct insertion_sort_dims_impl { | |
template<class Begin> | |
struct apply { | |
typedef typename insertion_sort_dims_impl<N - 1>::template apply<typename Begin::next>::type next; | |
typedef typename insertion_sort_dims_insert<(next::size::value)>::template apply<next, typename Begin::item>::type type; | |
}; | |
}; | |
template<> | |
struct insertion_sort_dims_impl<0> { | |
template<class Begin> | |
struct apply { | |
typedef dimensionless_type type; | |
}; | |
}; | |
template<class T> | |
struct sort_dims | |
{ | |
typedef typename insertion_sort_dims_mpl_sequence<mpl::size<T>::value>::template apply<typename mpl::begin<T>::type>::type type; | |
}; | |
template<class T, class Next> | |
struct sort_dims<list<T, Next> > | |
{ | |
typedef typename insertion_sort_dims_impl<list<T, Next>::size::value>::template apply<list<T, Next> >::type type; | |
}; | |
/// sorted sequences can be merged in linear time | |
template<bool less, bool greater> | |
struct merge_dimensions_func; | |
template<int N1, int N2> | |
struct merge_dimensions_impl; | |
template<> | |
struct merge_dimensions_func<true, false> | |
{ | |
template<typename Begin1, typename Begin2, int N1, int N2> | |
struct apply | |
{ | |
typedef list< | |
typename Begin1::item, | |
typename merge_dimensions_impl<N1 - 1, N2>::template apply< | |
typename Begin1::next, | |
Begin2 | |
>::type | |
> type; | |
}; | |
}; | |
template<> | |
struct merge_dimensions_func<false, true> { | |
template<typename Begin1, typename Begin2, int N1, int N2> | |
struct apply | |
{ | |
typedef list< | |
typename Begin2::item, | |
typename merge_dimensions_impl<N2 - 1, N1>::template apply< | |
typename Begin2::next, | |
Begin1 | |
>::type | |
> type; | |
}; | |
}; | |
template<> | |
struct merge_dimensions_func<false, false> { | |
template<typename Begin1, typename Begin2, int N1, int N2> | |
struct apply | |
{ | |
typedef typename mpl::plus<typename Begin1::item, typename Begin2::item>::type combined; | |
typedef typename push_front_if<!is_empty_dim<combined>::value>::template apply< | |
typename merge_dimensions_impl<N1 - 1, N2 - 1>::template apply< | |
typename Begin1::next, | |
typename Begin2::next | |
>::type, | |
combined | |
>::type type; | |
}; | |
}; | |
template<int N1, int N2> | |
struct merge_dimensions_impl { | |
template<typename Begin1, typename Begin2> | |
struct apply | |
{ | |
typedef typename Begin1::item dim1; | |
typedef typename Begin2::item dim2; | |
typedef typename merge_dimensions_func<(mpl::less<dim1,dim2>::value == true), | |
(mpl::less<dim2,dim1>::value == true)>::template apply< | |
Begin1, | |
Begin2, | |
N1, | |
N2 | |
>::type type; | |
}; | |
}; | |
template<typename Sequence1, typename Sequence2> | |
struct merge_dimensions | |
{ | |
typedef typename detail::merge_dimensions_impl<Sequence1::size::value, | |
Sequence2::size::value>::template | |
apply< | |
Sequence1, | |
Sequence2 | |
>::type type; | |
}; | |
template<int N> | |
struct iterator_to_list | |
{ | |
template<typename Begin> | |
struct apply | |
{ | |
typedef list< | |
typename Begin::item, | |
typename iterator_to_list<N - 1>::template apply< | |
typename Begin::next | |
>::type | |
> type; | |
}; | |
}; | |
template<> | |
struct iterator_to_list<0> | |
{ | |
template<typename Begin> | |
struct apply { | |
typedef dimensionless_type type; | |
}; | |
}; | |
template<int N> | |
struct merge_dimensions_impl<N, 0> | |
{ | |
template<typename Begin1, typename Begin2> | |
struct apply | |
{ | |
typedef typename iterator_to_list<N>::template apply<Begin1>::type type; | |
}; | |
}; | |
template<int N> | |
struct merge_dimensions_impl<0, N> | |
{ | |
template<typename Begin1, typename Begin2> | |
struct apply | |
{ | |
typedef typename iterator_to_list<N>::template apply<Begin2>::type type; | |
}; | |
}; | |
template<> | |
struct merge_dimensions_impl<0, 0> | |
{ | |
template<typename Begin1, typename Begin2> | |
struct apply | |
{ | |
typedef dimensionless_type type; | |
}; | |
}; | |
template<int N> | |
struct static_inverse_impl | |
{ | |
template<typename Begin> | |
struct apply { | |
typedef list< | |
typename mpl::negate<typename Begin::item>::type, | |
typename static_inverse_impl<N - 1>::template apply< | |
typename Begin::next | |
>::type | |
> type; | |
}; | |
}; | |
template<> | |
struct static_inverse_impl<0> | |
{ | |
template<typename Begin> | |
struct apply | |
{ | |
typedef dimensionless_type type; | |
}; | |
}; | |
template<int N> | |
struct static_power_impl | |
{ | |
template<typename Begin, typename Ex> | |
struct apply | |
{ | |
typedef list< | |
typename mpl::times<typename Begin::item, Ex>::type, | |
typename detail::static_power_impl<N - 1>::template apply<typename Begin::next, Ex>::type | |
> type; | |
}; | |
}; | |
template<> | |
struct static_power_impl<0> | |
{ | |
template<typename Begin, typename Ex> | |
struct apply | |
{ | |
typedef dimensionless_type type; | |
}; | |
}; | |
template<int N> | |
struct static_root_impl { | |
template<class Begin, class Ex> | |
struct apply { | |
typedef list< | |
typename mpl::divides<typename Begin::item, Ex>::type, | |
typename detail::static_root_impl<N - 1>::template apply<typename Begin::next, Ex>::type | |
> type; | |
}; | |
}; | |
template<> | |
struct static_root_impl<0> { | |
template<class Begin, class Ex> | |
struct apply | |
{ | |
typedef dimensionless_type type; | |
}; | |
}; | |
} // namespace detail | |
} // namespace units | |
} // namespace boost | |
#endif // BOOST_UNITS_DIMENSION_IMPL_HPP |