boost/mpl/max_element.hpp

0001
0002 #ifndef BOOST_MPL_MAX_ELEMENT_HPP_INCLUDED
0003 #define BOOST_MPL_MAX_ELEMENT_HPP_INCLUDED
0004
0005 // Copyright Aleksey Gurtovoy 2000-2004
0006 //
0007 // Distributed under the Boost Software License, Version 1.0.
0008 // (See accompanying file LICENSE_1_0.txt or copy at
0009 // http://www.boost.org/LICENSE_1_0.txt)
0010 //
0011 // See http://www.boost.org/libs/mpl for documentation.
0012
0013 // $Id$
0014 // $Date$
0015 // $Revision$
0016
0017 #include <boost/mpl/less.hpp>
0018 #include <boost/mpl/iter_fold.hpp>
0019 #include <boost/mpl/begin_end.hpp>
0020 #include <boost/mpl/if.hpp>
0021 #include <boost/mpl/deref.hpp>
0022 #include <boost/mpl/apply.hpp>
0023 #include <boost/mpl/aux_/common_name_wknd.hpp>
0024 #include <boost/mpl/aux_/na_spec.hpp>
0025
0026 namespace boost { namespace mpl {
0027
0028 BOOST_MPL_AUX_COMMON_NAME_WKND(max_element)
0029
0030 namespace aux {
0031
0032 template< typename Predicate >
0033 struct select_max
0034 {
0035     template< typename OldIterator, typename Iterator >
0036     struct apply
0037     {
0038         typedef typename apply2<
0039               Predicate
0040             , typename deref<OldIterator>::type
0041             , typename deref<Iterator>::type
0042             >::type condition_;
0043
0044         typedef typename if_<
0045               condition_
0046             , Iterator
0047             , OldIterator
0048             >::type type;
0049     };
0050 };
0051
0052 } // namespace aux
0053
0054
0055 template<
0056       typename BOOST_MPL_AUX_NA_PARAM(Sequence)
0057     , typename Predicate = less<_,_>
0058     >
0059 struct max_element
0060     : iter_fold<
0061           Sequence
0062         , typename begin<Sequence>::type
0063         , protect< aux::select_max<Predicate> >
0064         >
0065 {
0066 };
0067
0068 BOOST_MPL_AUX_NA_SPEC(1, max_element)
0069
0070 }}
0071
0072 #endif // BOOST_MPL_MAX_ELEMENT_HPP_INCLUDED