boost/boost/mpl/count_if.hpp

   1
   2 #ifndef BOOST_MPL_COUNT_IF_HPP_INCLUDED
   3 #define BOOST_MPL_COUNT_IF_HPP_INCLUDED
   4
   5 // Copyright Aleksey Gurtovoy 2000-2002
   6 //
   7 // Distributed under the Boost Software License, Version 1.0.
   8 // (See accompanying file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10 //
  11 // See http://www.boost.org/libs/mpl for documentation.
  12
  13 // $Id: count_if.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
  14 // $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $
  15 // $Revision: 49267 $
  16
  17 #include <boost/mpl/fold.hpp>
  18 #include <boost/mpl/next.hpp>
  19 #include <boost/mpl/integral_c.hpp>
  20 #include <boost/mpl/identity.hpp>
  21 #include <boost/mpl/eval_if.hpp>
  22 #include <boost/mpl/apply.hpp>
  23 #include <boost/mpl/aux_/msvc_eti_base.hpp>
  24 #include <boost/mpl/aux_/na_spec.hpp>
  25 #include <boost/mpl/aux_/lambda_support.hpp>
  26 #include <boost/mpl/aux_/config/forwarding.hpp>
  27
  28 namespace boost { namespace mpl {
  29
  30 namespace aux {
  31
  32 template< typename Predicate >
  33 struct next_if
  34 {
  35     template<
  36           typename N
  37         , typename T
  38         >
  39     struct apply
  40 #if !defined(BOOST_MPL_CFG_NO_NESTED_FORWARDING)
  41         : eval_if<
  42               typename apply1<Predicate,T>::type
  43             , next<N>
  44             , identity<N>
  45             >
  46     {
  47 #else
  48     {
  49         typedef typename eval_if<
  50               typename apply1<Predicate,T>::type
  51             , next<N>
  52             , identity<N>
  53             >::type type;
  54 #endif
  55     };
  56 };
  57
  58 } // namespace aux
  59
  60
  61 template<
  62       typename BOOST_MPL_AUX_NA_PARAM(Sequence)
  63     , typename BOOST_MPL_AUX_NA_PARAM(Predicate)
  64     >
  65 struct count_if
  66     : aux::msvc_eti_base< typename fold<
  67           Sequence
  68         , integral_c<unsigned long,0>
  69         , protect< aux::next_if<Predicate> >
  70         >::type >
  71 {
  72     BOOST_MPL_AUX_LAMBDA_SUPPORT(2,count_if,(Sequence,Predicate))
  73 };
  74
  75 BOOST_MPL_AUX_NA_SPEC(2, count_if)
  76
  77 }}
  78
  79 #endif // BOOST_MPL_COUNT_IF_HPP_INCLUDED