boost/mpl/aux_/filter_iter.hpp
#ifndef BOOST_MPL_AUX_FILTER_ITER_HPP_INCLUDED
#define BOOST_MPL_AUX_FILTER_ITER_HPP_INCLUDED
// Copyright Aleksey Gurtovoy 2000-2004
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/mpl for documentation.
// $Id$
// $Date$
// $Revision$
#include <boost/mpl/find_if.hpp>
#include <boost/mpl/iterator_range.hpp>
#include <boost/mpl/iterator_tags.hpp>
#include <boost/mpl/deref.hpp>
#include <boost/mpl/aux_/lambda_spec.hpp>
#include <boost/mpl/aux_/config/ctps.hpp>
#include <boost/type_traits/is_same.hpp>
namespace boost { namespace mpl {
namespace aux {
template<
typename Iterator
, typename LastIterator
, typename Predicate
>
struct filter_iter;
template<
typename Iterator
, typename LastIterator
, typename Predicate
>
struct next_filter_iter
{
typedef typename find_if<
iterator_range<Iterator,LastIterator>
, Predicate
>::type base_iter_;
typedef filter_iter<base_iter_,LastIterator,Predicate> type;
};
#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
template<
typename Iterator
, typename LastIterator
, typename Predicate
>
struct filter_iter
{
typedef Iterator base;
typedef forward_iterator_tag category;
typedef typename aux::next_filter_iter<
typename mpl::next<base>::type
, LastIterator
, Predicate
>::type next;
typedef typename deref<base>::type type;
};
template<
typename LastIterator
, typename Predicate
>
struct filter_iter< LastIterator,LastIterator,Predicate >
{
typedef LastIterator base;
typedef forward_iterator_tag category;
};
#else
template< bool >
struct filter_iter_impl
{
template<
typename Iterator
, typename LastIterator
, typename Predicate
>
struct result_
{
typedef Iterator base;
typedef forward_iterator_tag category;
typedef typename next_filter_iter<
typename mpl::next<Iterator>::type
, LastIterator
, Predicate
>::type next;
typedef typename deref<base>::type type;
};
};
template<>
struct filter_iter_impl< true >
{
template<
typename Iterator
, typename LastIterator
, typename Predicate
>
struct result_
{
typedef Iterator base;
typedef forward_iterator_tag category;
};
};
template<
typename Iterator
, typename LastIterator
, typename Predicate
>
struct filter_iter
: filter_iter_impl<
::boost::is_same<Iterator,LastIterator>::value
>::template result_< Iterator,LastIterator,Predicate >
{
};
#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
} // namespace aux
BOOST_MPL_AUX_PASS_THROUGH_LAMBDA_SPEC(3, aux::filter_iter)
}}
#endif // BOOST_MPL_AUX_FILTER_ITER_HPP_INCLUDED