boost/accumulators/numeric/functional/valarray.hpp
/////////////////////////////////////////////////////////////////////////////// /// \file valarray.hpp /// // Copyright 2005 Eric Niebler. 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_NUMERIC_FUNCTIONAL_VALARRAY_HPP_EAN_12_12_2005 #define BOOST_NUMERIC_FUNCTIONAL_VALARRAY_HPP_EAN_12_12_2005 #ifdef BOOST_NUMERIC_FUNCTIONAL_HPP_INCLUDED # error Include this file before boost/accumulators/numeric/functional.hpp #endif #include <valarray> #include <functional> #include <boost/assert.hpp> #include <boost/mpl/and.hpp> #include <boost/mpl/not.hpp> #include <boost/mpl/assert.hpp> #include <boost/utility/enable_if.hpp> #include <boost/type_traits/is_same.hpp> #include <boost/type_traits/is_scalar.hpp> #include <boost/type_traits/remove_const.hpp> #include <boost/typeof/std/valarray.hpp> #include <boost/accumulators/numeric/functional_fwd.hpp> namespace boost { namespace numeric { namespace operators { namespace acc_detail { template<typename Fun> struct make_valarray { typedef std::valarray<typename Fun::result_type> type; }; } /////////////////////////////////////////////////////////////////////////////// // Handle valarray<Left> / Right where Right is a scalar and Right != Left. template<typename Left, typename Right> typename lazy_enable_if< mpl::and_<is_scalar<Right>, mpl::not_<is_same<Left, Right> > > , acc_detail::make_valarray<functional::divides<Left, Right> > >::type operator /(std::valarray<Left> const &left, Right const &right) { typedef typename functional::divides<Left, Right>::result_type value_type; std::valarray<value_type> result(left.size()); for(std::size_t i = 0, size = result.size(); i != size; ++i) { result[i] = numeric::divides(left[i], right); } return result; } /////////////////////////////////////////////////////////////////////////////// // Handle valarray<Left> * Right where Right is a scalar and Right != Left. template<typename Left, typename Right> typename lazy_enable_if< mpl::and_<is_scalar<Right>, mpl::not_<is_same<Left, Right> > > , acc_detail::make_valarray<functional::multiplies<Left, Right> > >::type operator *(std::valarray<Left> const &left, Right const &right) { typedef typename functional::multiplies<Left, Right>::result_type value_type; std::valarray<value_type> result(left.size()); for(std::size_t i = 0, size = result.size(); i != size; ++i) { result[i] = numeric::multiplies(left[i], right); } return result; } /////////////////////////////////////////////////////////////////////////////// // Handle valarray<Left> + valarray<Right> where Right != Left. template<typename Left, typename Right> typename lazy_disable_if< is_same<Left, Right> , acc_detail::make_valarray<functional::plus<Left, Right> > >::type operator +(std::valarray<Left> const &left, std::valarray<Right> const &right) { typedef typename functional::plus<Left, Right>::result_type value_type; std::valarray<value_type> result(left.size()); for(std::size_t i = 0, size = result.size(); i != size; ++i) { result[i] = numeric::plus(left[i], right[i]); } return result; } } namespace functional { struct std_valarray_tag; template<typename T> struct tag<std::valarray<T> > { typedef std_valarray_tag type; }; #ifdef __GLIBCXX__ template<typename T, typename U> struct tag<std::_Expr<T, U> > { typedef std_valarray_tag type; }; #endif /// INTERNAL ONLY /// // This is necessary because the GCC stdlib uses expression templates, and // typeof(som-valarray-expression) is not an instance of std::valarray #define BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(Name, Op) \ template<typename Left, typename Right> \ struct Name<Left, Right, std_valarray_tag, std_valarray_tag> \ : std::binary_function< \ Left \ , Right \ , std::valarray< \ typename Name< \ typename Left::value_type \ , typename Right::value_type \ >::result_type \ > \ > \ { \ typedef typename Left::value_type left_value_type; \ typedef typename Right::value_type right_value_type; \ typedef \ std::valarray< \ typename Name<left_value_type, right_value_type>::result_type \ > \ result_type; \ result_type \ operator ()(Left &left, Right &right) const \ { \ return numeric::promote<std::valarray<left_value_type> >(left) \ Op numeric::promote<std::valarray<right_value_type> >(right); \ } \ }; \ template<typename Left, typename Right> \ struct Name<Left, Right, std_valarray_tag, void> \ : std::binary_function< \ Left \ , Right \ , std::valarray< \ typename Name<typename Left::value_type, Right>::result_type \ > \ > \ { \ typedef typename Left::value_type left_value_type; \ typedef \ std::valarray< \ typename Name<left_value_type, Right>::result_type \ > \ result_type; \ result_type \ operator ()(Left &left, Right &right) const \ { \ return numeric::promote<std::valarray<left_value_type> >(left) Op right;\ } \ }; \ template<typename Left, typename Right> \ struct Name<Left, Right, void, std_valarray_tag> \ : std::binary_function< \ Left \ , Right \ , std::valarray< \ typename Name<Left, typename Right::value_type>::result_type \ > \ > \ { \ typedef typename Right::value_type right_value_type; \ typedef \ std::valarray< \ typename Name<Left, right_value_type>::result_type \ > \ result_type; \ result_type \ operator ()(Left &left, Right &right) const \ { \ return left Op numeric::promote<std::valarray<right_value_type> >(right);\ } \ }; BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(plus, +) BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(minus, -) BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(multiplies, *) BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(divides, /) BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP(modulus, %) #undef BOOST_NUMERIC_FUNCTIONAL_DEFINE_VALARRAY_BIN_OP /////////////////////////////////////////////////////////////////////////////// // element-wise min of std::valarray template<typename Left, typename Right> struct min_assign<Left, Right, std_valarray_tag, std_valarray_tag> : std::binary_function<Left, Right, void> { void operator ()(Left &left, Right &right) const { BOOST_ASSERT(left.size() == right.size()); for(std::size_t i = 0, size = left.size(); i != size; ++i) { if(numeric::less(right[i], left[i])) { left[i] = right[i]; } } } }; /////////////////////////////////////////////////////////////////////////////// // element-wise max of std::valarray template<typename Left, typename Right> struct max_assign<Left, Right, std_valarray_tag, std_valarray_tag> : std::binary_function<Left, Right, void> { void operator ()(Left &left, Right &right) const { BOOST_ASSERT(left.size() == right.size()); for(std::size_t i = 0, size = left.size(); i != size; ++i) { if(numeric::greater(right[i], left[i])) { left[i] = right[i]; } } } }; // partial specialization of numeric::average<> for std::valarray. template<typename Left, typename Right, typename RightTag> struct average<Left, Right, std_valarray_tag, RightTag> : mpl::if_< are_integral<typename Left::value_type, Right> , divides<Left, double const> , divides<Left, Right> >::type {}; // promote template<typename To, typename From> struct promote<To, From, std_valarray_tag, std_valarray_tag> : std::unary_function<From, To> { To operator ()(From &arr) const { typename remove_const<To>::type res(arr.size()); for(std::size_t i = 0, size = arr.size(); i != size; ++i) { res[i] = numeric::promote<typename To::value_type>(arr[i]); } return res; } }; template<typename ToFrom> struct promote<ToFrom, ToFrom, std_valarray_tag, std_valarray_tag> : std::unary_function<ToFrom, ToFrom> { ToFrom &operator ()(ToFrom &tofrom) const { return tofrom; } }; // for "promoting" a std::valarray<bool> to a bool, useful for // comparing 2 valarrays for equality: // if(numeric::promote<bool>(a == b)) template<typename From> struct promote<bool, From, void, std_valarray_tag> : std::unary_function<From, bool> { bool operator ()(From &arr) const { BOOST_MPL_ASSERT((is_same<bool, typename From::value_type>)); for(std::size_t i = 0, size = arr.size(); i != size; ++i) { if(!arr[i]) { return false; } } return true; } }; template<typename From> struct promote<bool const, From, void, std_valarray_tag> : promote<bool, From, void, std_valarray_tag> {}; /////////////////////////////////////////////////////////////////////////////// // functional::as_min template<typename T> struct as_min<T, std_valarray_tag> : std::unary_function<T, typename remove_const<T>::type> { typename remove_const<T>::type operator ()(T &arr) const { return 0 == arr.size() ? T() : T(numeric::as_min(arr[0]), arr.size()); } }; /////////////////////////////////////////////////////////////////////////////// // functional::as_max template<typename T> struct as_max<T, std_valarray_tag> : std::unary_function<T, typename remove_const<T>::type> { typename remove_const<T>::type operator ()(T &arr) const { return 0 == arr.size() ? T() : T(numeric::as_max(arr[0]), arr.size()); } }; /////////////////////////////////////////////////////////////////////////////// // functional::as_zero template<typename T> struct as_zero<T, std_valarray_tag> : std::unary_function<T, typename remove_const<T>::type> { typename remove_const<T>::type operator ()(T &arr) const { return 0 == arr.size() ? T() : T(numeric::as_zero(arr[0]), arr.size()); } }; /////////////////////////////////////////////////////////////////////////////// // functional::as_one template<typename T> struct as_one<T, std_valarray_tag> : std::unary_function<T, typename remove_const<T>::type> { typename remove_const<T>::type operator ()(T &arr) const { return 0 == arr.size() ? T() : T(numeric::as_one(arr[0]), arr.size()); } }; } // namespace functional }} // namespace boost::numeric #endif