1
2#ifndef BOOST_MPL_INDEX_IF_HPP_INCLUDED
3#define BOOST_MPL_INDEX_IF_HPP_INCLUDED
4
5// Copyright Eric Friedman 2003
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/aux_/find_if_pred.hpp>
18#include <boost/mpl/begin_end.hpp>
19#include <boost/mpl/if.hpp>
20#include <boost/mpl/int.hpp>
21#include <boost/mpl/iter_fold_if.hpp>
22#include <boost/mpl/next.hpp>
23#include <boost/mpl/void.hpp>
24#include <boost/mpl/aux_/na_spec.hpp>
25#include <boost/mpl/aux_/lambda_support.hpp>
26#include <boost/type_traits/is_same.hpp>
27
28namespace boost { namespace mpl {
29
30template<
31 typename BOOST_MPL_AUX_NA_PARAM(Sequence)
32 , typename BOOST_MPL_AUX_NA_PARAM(Predicate)
33 >
34struct index_if
35{
36 typedef typename iter_fold_if<
37 Sequence
38 , int_<0>
39 , next<>
40 , aux::find_if_pred<Predicate>
41 >::type result_;
42
43 typedef typename end<Sequence>::type not_found_;
44 typedef typename first<result_>::type result_index_;
45 typedef typename second<result_>::type result_iterator_;
46
47 typedef typename if_<
48 is_same< result_iterator_,not_found_ >
49 , void_
50 , result_index_
51 >::type type;
52
53 BOOST_MPL_AUX_LAMBDA_SUPPORT(2,index_if,(Sequence,Predicate))
54};
55
56BOOST_MPL_AUX_NA_SPEC(2, index_if)
57
58}}
59
60#endif // BOOST_MPL_INDEX_IF_HPP_INCLUDED
61

source code of boost/boost/mpl/index_if.hpp