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/*
Copyright (c) Marshall Clow 2014.
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)
*/
/// \file is_permutation.hpp
/// \brief Is a sequence a permutation of another sequence (four iterator versions)
/// \author Marshall Clow
#ifndef BOOST_ALGORITHM_IS_PERMUTATION14_HPP
#define BOOST_ALGORITHM_IS_PERMUTATION14_HPP
#include <algorithm> // for std::less, tie, mismatch and is_permutation (if available)
#include <utility> // for std::make_pair
#include <functional> // for std::equal_to
#include <iterator>
#include <boost/algorithm/cxx11/is_permutation.hpp>
#include <boost/algorithm/cxx14/mismatch.hpp>
namespace boost { namespace algorithm {
/// \fn is_permutation ( ForwardIterator1 first, ForwardIterator1 last,
/// ForwardIterator2 first2, ForwardIterator2 last2 )
/// \brief Tests to see if the sequence [first,last) is a permutation of the sequence starting at first2
///
/// \param first1 The start of the input sequence
/// \param last2 One past the end of the input sequence
/// \param first2 The start of the second sequence
/// \param last1 One past the end of the second sequence
/// \note This function is part of the C++2014 standard library.
/// We will use the standard one if it is available,
/// otherwise we have our own implementation.
template< class ForwardIterator1, class ForwardIterator2 >
bool is_permutation ( ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2 )
{
// How should I deal with the idea that ForwardIterator1::value_type
// and ForwardIterator2::value_type could be different? Define my own comparison predicate?
std::pair<ForwardIterator1, ForwardIterator2> eq = boost::algorithm::mismatch
( first1, last1, first2, last2 );
if ( eq.first == last1 && eq.second == last2)
return true;
return boost::algorithm::detail::is_permutation_tag (
eq.first, last1, eq.second, last2,
std::equal_to<typename std::iterator_traits<ForwardIterator1>::value_type> (),
typename std::iterator_traits<ForwardIterator1>::iterator_category (),
typename std::iterator_traits<ForwardIterator2>::iterator_category ());
}
/// \fn is_permutation ( ForwardIterator1 first, ForwardIterator1 last,
/// ForwardIterator2 first2, ForwardIterator2 last2,
/// BinaryPredicate p )
/// \brief Tests to see if the sequence [first,last) is a permutation of the sequence starting at first2
///
/// \param first1 The start of the input sequence
/// \param last1 One past the end of the input sequence
/// \param first2 The start of the second sequence
/// \param last2 One past the end of the second sequence
/// \param pred The predicate to compare elements with
///
/// \note This function is part of the C++2014 standard library.
/// We will use the standard one if it is available,
/// otherwise we have our own implementation.
template< class ForwardIterator1, class ForwardIterator2, class BinaryPredicate >
bool is_permutation ( ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred )
{
std::pair<ForwardIterator1, ForwardIterator2> eq = boost::algorithm::mismatch
( first1, last1, first2, last2, pred );
if ( eq.first == last1 && eq.second == last2)
return true;
return boost::algorithm::detail::is_permutation_tag (
first1, last1, first2, last2, pred,
typename std::iterator_traits<ForwardIterator1>::iterator_category (),
typename std::iterator_traits<ForwardIterator2>::iterator_category ());
}
}}
#endif // BOOST_ALGORITHM_IS_PERMUTATION14_HPP
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