source: NonGTP/Boost/boost/mpl/index_if.hpp @ 857

Revision 857, 1.6 KB checked in by igarcia, 19 years ago (diff)
RevLine 
[857]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// $Source: /cvsroot/boost/boost/boost/mpl/index_if.hpp,v $
14// $Date: 2004/09/02 15:40:41 $
15// $Revision: 1.7 $
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
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