From: steven_watanabe_at_[hidden]
Date: 2007-05-29 20:08:08
Author: steven_watanabe
Date: 2007-05-29 20:08:07 EDT (Tue, 29 May 2007)
New Revision: 4357
URL: http://svn.boost.org/trac/boost/changeset/4357
Log:
optimizations
Text files modified:
sandbox/units/boost/units/detail/linear_algebra.hpp | 116 ++++++++++++++++++++++++++++++++-------
sandbox/units/boost/units/scaled_base_unit.hpp | 2
2 files changed, 96 insertions(+), 22 deletions(-)
Modified: sandbox/units/boost/units/detail/linear_algebra.hpp
==============================================================================
--- sandbox/units/boost/units/detail/linear_algebra.hpp (original)
+++ sandbox/units/boost/units/detail/linear_algebra.hpp 2007-05-29 20:08:07 EDT (Tue, 29 May 2007)
@@ -951,6 +951,7 @@
};
};
+
// strip_zeroes erases the first N elements of a list if
// they are all zero, otherwise returns inconsistant
//
@@ -1019,29 +1020,102 @@
// used many times, the cost of creating
// a system is probably not significant.
+template<class T>
+struct is_base_dimension_unit {
+ typedef mpl::false_ type;
+ typedef void base_dimension_type;
+};
+template<class T>
+struct is_base_dimension_unit<dimension_list<dim<T, static_rational<1> >, dimensionless_type> > {
+ typedef mpl::true_ type;
+ typedef T base_dimension_type;
+};
+
+template<int N>
+struct is_simple_system_impl {
+ template<class Begin, class Prev>
+ struct apply {
+ typedef is_base_dimension_unit<typename mpl::deref<Begin>::type::dimension_type> test;
+ typedef mpl::and_<
+ typename test::type,
+ mpl::less<Prev, typename test::base_dimension_type>,
+ typename is_simple_system_impl<N-1>::template apply<
+ typename mpl::next<Begin>::type,
+ typename test::base_dimension_type
+ >
+ > type;
+ static const bool value = (type::value);
+ };
+};
+
+template<>
+struct is_simple_system_impl<0> {
+ template<class Begin, class Prev>
+ struct apply : mpl::true_ {
+ };
+};
+
+template<class T>
+struct is_simple_system {
+ typedef typename mpl::begin<T>::type Begin;
+ typedef is_base_dimension_unit<typename mpl::deref<Begin>::type> test;
+ typedef typename mpl::and_<
+ typename test::type,
+ typename is_simple_system_impl<
+ mpl::size<T>::value - 1
+ >::template apply<
+ typename mpl::next<Begin>::type,
+ typename test::base_dimension_type
+ >
+ >::type type;
+ static const bool value = type::value;
+};
+
+template<bool>
+struct calculate_base_unit_exponents_impl;
+
+template<>
+struct calculate_base_unit_exponents_impl<true> {
+ template<class T, class Dimensions>
+ struct apply {
+ typedef typename expand_dimensions<mpl::size<T>::value>::template apply<
+ typename mpl::begin<typename find_base_dimensions<T>::type>::type,
+ typename mpl::begin<Dimensions>::type
+ >::type type;
+ };
+};
+
+template<>
+struct calculate_base_unit_exponents_impl<false> {
+ template<class T, class Dimensions>
+ struct apply {
+ // find the units that correspond to each base dimension
+ typedef normalize_units<T> base_solutions;
+ // pad the dimension with zeroes so it can just be a
+ // list of numbers, making the multiplication easy
+ // e.g. if the arguments are list<pound, foot> and
+ // dimension_list<mass,time^-2> then this step will
+ // yield list<0,1,-2>
+ typedef typename expand_dimensions<mpl::size<typename base_solutions::dimensions>::value>::template apply<
+ typename mpl::begin<typename base_solutions::dimensions>::type,
+ typename mpl::begin<Dimensions>::type
+ >::type dimensions;
+ // take the unit corresponding to each base unit
+ // multiply each of its exponents by the exponent
+ // of the base_dimension in the result and sum.
+ typedef typename multiply_add_units<mpl::size<dimensions>::value>::template apply<
+ typename mpl::begin<dimensions>::type,
+ typename mpl::begin<typename base_solutions::type>::type
+ >::type units;
+ // Now, verify that the dummy units really
+ // cancel out and remove them.
+ typedef typename strip_zeroes_impl<base_solutions::extra>::template apply<units>::type type;
+ };
+};
+
template<class T, class Dimensions>
struct calculate_base_unit_exponents {
- // find the units that correspond to each base dimension
- typedef normalize_units<T> base_solutions;
- // pad the dimension with zeroes so it can just be a
- // list of numbers, making the multiplication easy
- // e.g. if the arguments are list<pound, foot> and
- // dimension_list<mass,time^-2> then this step will
- // yield list<0,1,-2>
- typedef typename expand_dimensions<mpl::size<typename base_solutions::dimensions>::value>::template apply<
- typename mpl::begin<typename base_solutions::dimensions>::type,
- typename mpl::begin<Dimensions>::type
- >::type dimensions;
- // take the unit corresponding to each base unit
- // multiply each of its exponents by the exponent
- // of the base_dimension in the result and sum.
- typedef typename multiply_add_units<mpl::size<dimensions>::value>::template apply<
- typename mpl::begin<dimensions>::type,
- typename mpl::begin<typename base_solutions::type>::type
- >::type units;
- // Now, verify that the dummy units really
- // cancel out and remove them.
- typedef typename strip_zeroes_impl<base_solutions::extra>::template apply<units>::type type;
+ typedef typename calculate_base_unit_exponents_impl<is_simple_system<T>::value>::template apply<T, Dimensions>::type type;
};
} // namespace detail
Modified: sandbox/units/boost/units/scaled_base_unit.hpp
==============================================================================
--- sandbox/units/boost/units/scaled_base_unit.hpp (original)
+++ sandbox/units/boost/units/scaled_base_unit.hpp 2007-05-29 20:08:07 EDT (Tue, 29 May 2007)
@@ -135,7 +135,7 @@
} // namespace boost
-#ifdef BOOST_UNITS_HAS_BOOST_TYPEOF
+#if BOOST_UNITS_HAS_BOOST_TYPEOF
#include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP()