accumulators/statistics/count.hpp

0001 ///////////////////////////////////////////////////////////////////////////////
0002 // count.hpp
0003 //
0004 //  Copyright 2005 Eric Niebler. Distributed under the Boost
0005 //  Software License, Version 1.0. (See accompanying file
0006 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007
0008 #ifndef BOOST_ACCUMULATORS_STATISTICS_COUNT_HPP_EAN_28_10_2005
0009 #define BOOST_ACCUMULATORS_STATISTICS_COUNT_HPP_EAN_28_10_2005
0010
0011 #include <boost/mpl/always.hpp>
0012 #include <boost/accumulators/framework/accumulator_base.hpp>
0013 #include <boost/accumulators/framework/extractor.hpp>
0014 #include <boost/accumulators/framework/depends_on.hpp>
0015 #include <boost/accumulators/statistics_fwd.hpp>
0016
0017 namespace boost { namespace accumulators
0018 {
0019
0020 namespace impl
0021 {
0022
0023     ///////////////////////////////////////////////////////////////////////////////
0024     // count_impl
0025     struct count_impl
0026       : accumulator_base
0027     {
0028         // for boost::result_of
0029         typedef std::size_t result_type;
0030
0031         count_impl(dont_care)
0032           : cnt(0)
0033         {
0034         }
0035
0036         void operator ()(dont_care)
0037         {
0038             ++this->cnt;
0039         }
0040
0041         result_type result(dont_care) const
0042         {
0043             return this->cnt;
0044         }
0045
0046         // make this accumulator serializeable
0047         template<class Archive>
0048         void serialize(Archive & ar, const unsigned int /* file_version */)
0049         {
0050             ar & cnt;
0051         }
0052
0053     private:
0054         std::size_t cnt;
0055     };
0056
0057 } // namespace impl
0058
0059 ///////////////////////////////////////////////////////////////////////////////
0060 // tag::count
0061 //
0062 namespace tag
0063 {
0064     struct count
0065       : depends_on<>
0066     {
0067         /// INTERNAL ONLY
0068         ///
0069         typedef mpl::always<accumulators::impl::count_impl> impl;
0070     };
0071 }
0072
0073 ///////////////////////////////////////////////////////////////////////////////
0074 // extract::count
0075 //
0076 namespace extract
0077 {
0078     extractor<tag::count> const count = {};
0079
0080     BOOST_ACCUMULATORS_IGNORE_GLOBAL(count)
0081 }
0082
0083 using extract::count;
0084
0085 }} // namespace boost::accumulators
0086
0087 #endif