Rework the file layout and implementation of 'is_permutation' to match the various versions of the C++ standard. In particular, move the four iterator versions into the cxx14/ directory.

include/boost/algorithm/cxx11/is_permutation.hpp

@@ -9,8 +9,8 @@
 /// \brief Is a sequence a permutation of another sequence
 /// \author Marshall Clow
 
-#ifndef BOOST_ALGORITHM_IS_PERMUTATION_HPP
+#ifndef BOOST_ALGORITHM_IS_PERMUTATION11_HPP
-#define BOOST_ALGORITHM_IS_PERMUTATION_HPP
+#define BOOST_ALGORITHM_IS_PERMUTATION11_HPP
 
 #include <algorithm>    // for std::less, tie, mismatch and is_permutation (if available)
 #include <utility>      // for std::make_pair
@@ -163,58 +163,6 @@ bool is_permutation ( ForwardIterator1 first1, ForwardIterator1 last1, ForwardIt
 
 #endif
 
-#if __cplusplus <= 201103L
-/// \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?
-    return boost::algorithm::detail::is_permutation_tag (
-        first1, last1, first2, 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 )
-{
-    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
-
-
 
 /// \fn is_permutation ( const Range &r, ForwardIterator first2 )
 /// \brief Tests to see if the sequence [first,last) is a permutation of the sequence starting at first2
@@ -245,4 +193,4 @@ is_permutation ( const Range &r, ForwardIterator first2, BinaryPredicate pred )
 
 }}
 
-#endif  // BOOST_ALGORITHM_IS_PERMUTATION_HPP
+#endif  // BOOST_ALGORITHM_IS_PERMUTATION11_HPP

include/boost/algorithm/cxx14/is_permutation.hpp

@@ -0,0 +1,86 @@
+/*
+   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 {
+
+#if __cplusplus <= 201103L
+/// \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
+
+}}
+
+#endif  // BOOST_ALGORITHM_IS_PERMUTATION14_HPP

test/is_permutation_test1.cpp

@@ -11,6 +11,7 @@
 
 #include <boost/config.hpp>
 #include <boost/algorithm/cxx11/is_permutation.hpp>
+#include <boost/algorithm/cxx14/is_permutation.hpp>
 
 #define BOOST_TEST_MAIN
 #include <boost/test/unit_test.hpp>