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Diffstat (limited to 'boost/fusion/algorithm/query/detail/count_if.hpp')
-rw-r--r-- | boost/fusion/algorithm/query/detail/count_if.hpp | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/boost/fusion/algorithm/query/detail/count_if.hpp b/boost/fusion/algorithm/query/detail/count_if.hpp new file mode 100644 index 0000000000..7110071ddf --- /dev/null +++ b/boost/fusion/algorithm/query/detail/count_if.hpp @@ -0,0 +1,170 @@ +/*============================================================================= + Copyright (c) 2001-2011 Joel de Guzman + Copyright (c) 2007 Dan Marsden + + 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) +==============================================================================*/ +#if !defined(BOOST_FUSION_COUNT_IF_09162005_0141) +#define BOOST_FUSION_COUNT_IF_09162005_0141 + +#include <boost/mpl/bool.hpp> +#include <boost/fusion/sequence/intrinsic/begin.hpp> +#include <boost/fusion/sequence/intrinsic/end.hpp> +#include <boost/fusion/iterator/equal_to.hpp> +#include <boost/fusion/iterator/next.hpp> +#include <boost/fusion/iterator/deref.hpp> +#include <boost/fusion/iterator/equal_to.hpp> +#include <boost/fusion/iterator/distance.hpp> +#include <boost/fusion/iterator/advance.hpp> + +namespace boost { namespace fusion { + struct random_access_traversal_tag; +namespace detail +{ + template <typename First, typename Last, typename F> + inline int + linear_count_if(First const&, Last const&, F const&, mpl::true_) + { + return 0; + } + + template <typename First, typename Last, typename F> + inline int + linear_count_if(First const& first, Last const& last, F& f, mpl::false_) + { + int n = + detail::linear_count_if( + fusion::next(first) + , last + , f + , result_of::equal_to<typename result_of::next<First>::type, Last>()); + if (f(*first)) + ++n; + return n; + } + + template <typename Sequence, typename F, typename Tag> + inline int + count_if(Sequence const& seq, F f, Tag) + { + return detail::linear_count_if( + fusion::begin(seq) + , fusion::end(seq) + , f + , result_of::equal_to< + typename result_of::begin<Sequence>::type + , typename result_of::end<Sequence>::type>()); + } + + template<int n> + struct unrolled_count_if + { + template<typename I0, typename F> + static int call(I0 const& i0, F f) + { + int ct = unrolled_count_if<n-4>:: + call(fusion::advance_c<4>(i0), f); + if(f(*i0)) + ++ct; + + typedef typename result_of::next<I0>::type I1; + I1 i1(fusion::next(i0)); + if(f(*i1)) + ++ct; + + typedef typename result_of::next<I1>::type I2; + I2 i2(fusion::next(i1)); + if(f(*i2)) + ++ct; + + typedef typename result_of::next<I2>::type I3; + I3 i3(fusion::next(i2)); + if(f(*i3)) + ++ct; + + return ct; + } + }; + + template<> + struct unrolled_count_if<3> + { + template<typename I0, typename F> + static int call(I0 const& i0, F f) + { + int ct = 0; + if(f(*i0)) + ++ct; + + typedef typename result_of::next<I0>::type I1; + I1 i1(fusion::next(i0)); + if(f(*i1)) + ++ct; + + typedef typename result_of::next<I1>::type I2; + I2 i2(fusion::next(i1)); + if(f(*i2)) + ++ct; + + return ct; + } + }; + + template<> + struct unrolled_count_if<2> + { + template<typename I0, typename F> + static int call(I0 const& i0, F f) + { + int ct = 0; + + if(f(*i0)) + ++ct; + + typedef typename result_of::next<I0>::type I1; + I1 i1(fusion::next(i0)); + if(f(*i1)) + ++ct; + + return ct; + } + }; + + template<> + struct unrolled_count_if<1> + { + template<typename I0, typename F> + static int call(I0 const& i0, F f) + { + int ct = 0; + if(f(*i0)) + ++ct; + return ct; + } + }; + + + template<> + struct unrolled_count_if<0> + { + template<typename I0, typename F> + static int call(I0 const&, F) + { + return 0; + } + }; + + template <typename Sequence, typename F> + inline int + count_if(Sequence const& seq, F f, random_access_traversal_tag) + { + typedef typename result_of::begin<Sequence>::type begin; + typedef typename result_of::end<Sequence>::type end; + return detail::unrolled_count_if<result_of::distance<begin, end>::type::value>:: + call(fusion::begin(seq), f); + } +}}} + +#endif + |