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// $Id$
14// $Date$
15// $Revision$
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
28namespace boost { namespace mpl {
29
30namespace aux {
31
32template< typename Predicate >
33struct 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
61template<
62 typename BOOST_MPL_AUX_NA_PARAM(Sequence)
63 , typename BOOST_MPL_AUX_NA_PARAM(Predicate)
64 >
65struct 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
75BOOST_MPL_AUX_NA_SPEC(2, count_if)
76
77}}
78
79#endif // BOOST_MPL_COUNT_IF_HPP_INCLUDED
80

source code of boost/libs/mpl/include/boost/mpl/count_if.hpp