Implement n3607: 'equal', 'mismatch', and 'is_permutation'

llvm-svn: 181548
diff --git a/libcxx/test/algorithms/alg.nonmodifying/alg.equal/equal.pass.cpp b/libcxx/test/algorithms/alg.nonmodifying/alg.equal/equal.pass.cpp
index 1b1a2ad..6ecd491 100644
--- a/libcxx/test/algorithms/alg.nonmodifying/alg.equal/equal.pass.cpp
+++ b/libcxx/test/algorithms/alg.nonmodifying/alg.equal/equal.pass.cpp
@@ -19,6 +19,10 @@
 
 #include "test_iterators.h"
 
+#if _LIBCPP_STD_VER > 11
+#define	HAS_FOUR_ITERATOR_VERSION
+#endif
+
 int main()
 {
     int ia[] = {0, 1, 2, 3, 4, 5};
@@ -27,7 +31,36 @@
     assert(std::equal(input_iterator<const int*>(ia),
                       input_iterator<const int*>(ia+s),
                       input_iterator<const int*>(ia)));
+#ifdef HAS_FOUR_ITERATOR_VERSION
+    assert(std::equal(input_iterator<const int*>(ia),
+                      input_iterator<const int*>(ia+s),
+                      input_iterator<const int*>(ia),
+                      input_iterator<const int*>(ia+s)));
+    assert(std::equal(random_access_iterator<const int*>(ia),
+                      random_access_iterator<const int*>(ia+s),
+                      random_access_iterator<const int*>(ia),
+                      random_access_iterator<const int*>(ia+s)));
+#endif
     assert(!std::equal(input_iterator<const int*>(ia),
                        input_iterator<const int*>(ia+s),
                        input_iterator<const int*>(ib)));
+#ifdef HAS_FOUR_ITERATOR_VERSION
+    assert(!std::equal(input_iterator<const int*>(ia),
+                       input_iterator<const int*>(ia+s),
+                       input_iterator<const int*>(ib),
+                       input_iterator<const int*>(ib+s)));
+    assert(!std::equal(random_access_iterator<const int*>(ia),
+                       random_access_iterator<const int*>(ia+s),
+                       random_access_iterator<const int*>(ib),
+                       random_access_iterator<const int*>(ib+s)));
+    assert(!std::equal(input_iterator<const int*>(ia),
+                       input_iterator<const int*>(ia+s),
+                       input_iterator<const int*>(ia),
+                       input_iterator<const int*>(ia+s-1)));
+    assert(!std::equal(random_access_iterator<const int*>(ia),
+                       random_access_iterator<const int*>(ia+s),
+                       random_access_iterator<const int*>(ia),
+                       random_access_iterator<const int*>(ia+s-1)));
+    
+#endif
 }
diff --git a/libcxx/test/algorithms/alg.nonmodifying/alg.equal/equal_pred.pass.cpp b/libcxx/test/algorithms/alg.nonmodifying/alg.equal/equal_pred.pass.cpp
index b21d38b6..b898220 100644
--- a/libcxx/test/algorithms/alg.nonmodifying/alg.equal/equal_pred.pass.cpp
+++ b/libcxx/test/algorithms/alg.nonmodifying/alg.equal/equal_pred.pass.cpp
@@ -21,6 +21,17 @@
 
 #include "test_iterators.h"
 
+#if _LIBCPP_STD_VER > 11
+#define	HAS_FOUR_ITERATOR_VERSION
+#endif
+
+int comparison_count = 0;
+template <typename T>
+bool counting_equals ( const T &a, const T &b ) {
+	++comparison_count;
+	return a == b;
+	}
+
 int main()
 {
     int ia[] = {0, 1, 2, 3, 4, 5};
@@ -30,8 +41,47 @@
                       input_iterator<const int*>(ia+s),
                       input_iterator<const int*>(ia),
                       std::equal_to<int>()));
+#ifdef HAS_FOUR_ITERATOR_VERSION
+    assert(std::equal(input_iterator<const int*>(ia),
+                      input_iterator<const int*>(ia+s),
+                      input_iterator<const int*>(ia),
+                      input_iterator<const int*>(ia+s),
+                      std::equal_to<int>()));
+    assert(std::equal(random_access_iterator<const int*>(ia),
+                      random_access_iterator<const int*>(ia+s),
+                      random_access_iterator<const int*>(ia),
+                      random_access_iterator<const int*>(ia+s),
+                      std::equal_to<int>()));
+
+    comparison_count = 0;
+    assert(!std::equal(input_iterator<const int*>(ia),
+                      input_iterator<const int*>(ia+s),
+                      input_iterator<const int*>(ia),
+                      input_iterator<const int*>(ia+s-1),
+                      counting_equals<int>));
+    assert(comparison_count > 0);
+    comparison_count = 0;
+    assert(!std::equal(random_access_iterator<const int*>(ia),
+                      random_access_iterator<const int*>(ia+s),
+                      random_access_iterator<const int*>(ia),
+                      random_access_iterator<const int*>(ia+s-1),
+                      counting_equals<int>));
+    assert(comparison_count == 0);
+#endif
     assert(!std::equal(input_iterator<const int*>(ia),
                        input_iterator<const int*>(ia+s),
                        input_iterator<const int*>(ib),
                        std::equal_to<int>()));
+#ifdef HAS_FOUR_ITERATOR_VERSION
+    assert(!std::equal(input_iterator<const int*>(ia),
+                       input_iterator<const int*>(ia+s),
+                       input_iterator<const int*>(ib),
+                       input_iterator<const int*>(ib+s),
+                       std::equal_to<int>()));
+    assert(!std::equal(random_access_iterator<const int*>(ia),
+                       random_access_iterator<const int*>(ia+s),
+                       random_access_iterator<const int*>(ib),
+                       random_access_iterator<const int*>(ib+s),
+                       std::equal_to<int>()));
+#endif
 }
diff --git a/libcxx/test/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation.pass.cpp b/libcxx/test/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation.pass.cpp
index f68cced..8b5ba60 100644
--- a/libcxx/test/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation.pass.cpp
+++ b/libcxx/test/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation.pass.cpp
@@ -19,6 +19,10 @@
 
 #include "test_iterators.h"
 
+#if _LIBCPP_STD_VER > 11
+#define	HAS_FOUR_ITERATOR_VERSION
+#endif
+
 int main()
 {
     {
@@ -28,9 +32,25 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + 0),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + 0),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + 0)) == true);
+#endif
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0};
@@ -39,6 +59,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
 
     {
@@ -48,6 +74,16 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0};
@@ -56,6 +92,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0};
@@ -64,6 +106,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0};
@@ -72,6 +120,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1};
@@ -80,6 +134,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1};
@@ -88,6 +148,16 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1};
@@ -96,6 +166,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+#endif
     }
     {
         const int ia[] = {0, 1};
@@ -104,6 +180,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {1, 0};
@@ -112,6 +194,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {1, 0};
@@ -120,6 +208,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+#endif
     }
     {
         const int ia[] = {1, 0};
@@ -128,6 +222,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+#endif
     }
     {
         const int ia[] = {1, 0};
@@ -136,6 +236,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {1, 1};
@@ -144,6 +250,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {1, 1};
@@ -152,6 +264,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {1, 1};
@@ -160,6 +278,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {1, 1};
@@ -168,6 +292,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+#endif
     }
 
     {
@@ -177,6 +307,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -185,6 +321,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -193,6 +335,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -201,6 +349,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -209,6 +363,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -217,6 +377,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -225,6 +391,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -233,6 +405,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -241,6 +419,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 1};
@@ -249,6 +433,16 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 1};
@@ -257,6 +451,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2};
@@ -265,6 +465,16 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2};
@@ -273,6 +483,16 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2};
@@ -281,6 +501,16 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2};
@@ -289,6 +519,16 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 1};
@@ -297,6 +537,12 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 1};
@@ -305,6 +551,20 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib + 1),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2, 3, 0, 5, 6, 2, 4, 4};
@@ -313,6 +573,20 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib + 1 ),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1)) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2, 3, 0, 5, 6, 2, 4, 4};
@@ -321,5 +595,11 @@
         assert(std::is_permutation(forward_iterator<const int*>(ia),
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib)) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa)) == false);
+#endif
     }
 }
diff --git a/libcxx/test/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp b/libcxx/test/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp
index 2a3174f..ceb897da 100644
--- a/libcxx/test/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp
+++ b/libcxx/test/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp
@@ -20,6 +20,18 @@
 
 #include "test_iterators.h"
 
+#if _LIBCPP_STD_VER > 11
+#define HAS_FOUR_ITERATOR_VERSION
+#endif
+
+int comparison_count = 0;
+template <typename T>
+bool counting_equals ( const T &a, const T &b ) {
+    ++comparison_count;
+    return a == b;
+    }
+
+
 int main()
 {
     {
@@ -34,6 +46,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0};
@@ -43,6 +67,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
 
     {
@@ -53,6 +84,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0};
@@ -62,6 +105,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0};
@@ -71,6 +121,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0};
@@ -80,6 +137,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1};
@@ -89,6 +153,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1};
@@ -98,6 +169,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1};
@@ -107,6 +190,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1};
@@ -116,6 +211,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {1, 0};
@@ -125,6 +227,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {1, 0};
@@ -134,6 +243,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {1, 0};
@@ -143,6 +264,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {1, 0};
@@ -152,6 +285,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {1, 1};
@@ -161,6 +301,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {1, 1};
@@ -170,6 +317,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {1, 1};
@@ -179,6 +333,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {1, 1};
@@ -188,6 +349,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
 
     {
@@ -198,6 +371,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -207,6 +387,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -216,6 +403,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -225,6 +419,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -234,6 +435,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -243,6 +451,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -252,6 +467,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -261,6 +483,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 0};
@@ -270,6 +499,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 1};
@@ -279,6 +515,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 1};
@@ -288,6 +536,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2};
@@ -297,6 +552,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2};
@@ -306,6 +573,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2};
@@ -315,6 +594,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2};
@@ -324,6 +615,18 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 1};
@@ -333,6 +636,13 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 0, 1};
@@ -342,6 +652,23 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib + 1),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
     {
         const int ia[] = {0, 1, 2, 3, 0, 5, 6, 2, 4, 4};
@@ -351,6 +678,37 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == true);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == true);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib + 1),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   std::equal_to<const int>()) == false);
+        comparison_count = 0;
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa - 1),
+                                   counting_equals<const int>) == false);
+        assert ( comparison_count > 0 );
+        comparison_count = 0;
+        assert(std::is_permutation(random_access_iterator<const int*>(ia),
+                                   random_access_iterator<const int*>(ia + sa),
+                                   random_access_iterator<const int*>(ib),
+                                   random_access_iterator<const int*>(ib + sa - 1),
+                                   counting_equals<const int>) == false);
+        assert ( comparison_count == 0 );
+#endif
     }
     {
         const int ia[] = {0, 1, 2, 3, 0, 5, 6, 2, 4, 4};
@@ -360,5 +718,12 @@
                                    forward_iterator<const int*>(ia + sa),
                                    forward_iterator<const int*>(ib),
                                    std::equal_to<const int>()) == false);
+#ifdef HAS_FOUR_ITERATOR_VERSION
+        assert(std::is_permutation(forward_iterator<const int*>(ia),
+                                   forward_iterator<const int*>(ia + sa),
+                                   forward_iterator<const int*>(ib),
+                                   forward_iterator<const int*>(ib + sa),
+                                   std::equal_to<const int>()) == false);
+#endif
     }
 }
diff --git a/libcxx/test/algorithms/alg.nonmodifying/mismatch/mismatch.pass.cpp b/libcxx/test/algorithms/alg.nonmodifying/mismatch/mismatch.pass.cpp
index 9dfebac..fe67854 100644
--- a/libcxx/test/algorithms/alg.nonmodifying/mismatch/mismatch.pass.cpp
+++ b/libcxx/test/algorithms/alg.nonmodifying/mismatch/mismatch.pass.cpp
@@ -19,6 +19,10 @@
 
 #include "test_iterators.h"
 
+#if _LIBCPP_STD_VER > 11
+#define HAS_FOUR_ITERATOR_VERSION
+#endif
+
 int main()
 {
     int ia[] = {0, 1, 2, 2, 0, 1, 2, 3};
@@ -31,4 +35,24 @@
                                     input_iterator<const int*> >(
                             input_iterator<const int*>(ia+3),
                             input_iterator<const int*>(ib+3))));
+
+#ifdef HAS_FOUR_ITERATOR_VERSION
+    assert(std::mismatch(input_iterator<const int*>(ia),
+                         input_iterator<const int*>(ia + sa),
+                         input_iterator<const int*>(ib),
+                         input_iterator<const int*>(ib + sa)) ==
+                         (std::pair<input_iterator<const int*>,
+                                    input_iterator<const int*> >(
+                            input_iterator<const int*>(ia+3),
+                            input_iterator<const int*>(ib+3))));
+
+    assert(std::mismatch(input_iterator<const int*>(ia),
+                         input_iterator<const int*>(ia + sa),
+                         input_iterator<const int*>(ib),
+                         input_iterator<const int*>(ib + 2)) ==
+                         (std::pair<input_iterator<const int*>,
+                                    input_iterator<const int*> >(
+                            input_iterator<const int*>(ia+2),
+                            input_iterator<const int*>(ib+2))));
+#endif
 }
diff --git a/libcxx/test/algorithms/alg.nonmodifying/mismatch/mismatch_pred.pass.cpp b/libcxx/test/algorithms/alg.nonmodifying/mismatch/mismatch_pred.pass.cpp
index 0258479..202a1b7 100644
--- a/libcxx/test/algorithms/alg.nonmodifying/mismatch/mismatch_pred.pass.cpp
+++ b/libcxx/test/algorithms/alg.nonmodifying/mismatch/mismatch_pred.pass.cpp
@@ -21,6 +21,11 @@
 
 #include "test_iterators.h"
 
+#if _LIBCPP_STD_VER > 11
+#define HAS_FOUR_ITERATOR_VERSION
+#endif
+
+
 int main()
 {
     int ia[] = {0, 1, 2, 2, 0, 1, 2, 3};
@@ -34,6 +39,24 @@
                                     input_iterator<const int*> >(
                             input_iterator<const int*>(ia+3),
                             input_iterator<const int*>(ib+3))));
+#ifdef HAS_FOUR_ITERATOR_VERSION
+    assert(std::mismatch(input_iterator<const int*>(ia),
+                         input_iterator<const int*>(ia + sa),
+                         input_iterator<const int*>(ib),
+                         input_iterator<const int*>(ib + sa),
+                         std::equal_to<int>()) ==
+                         (std::pair<input_iterator<const int*>,
+                                    input_iterator<const int*> >(
+                            input_iterator<const int*>(ia+3),
+                            input_iterator<const int*>(ib+3))));
+#endif
+
     assert(std::mismatch(ia, ia + sa, ib, std::equal_to<int>()) ==
            (std::pair<int*,int*>(ia+3,ib+3)));
+#ifdef HAS_FOUR_ITERATOR_VERSION
+    assert(std::mismatch(ia, ia + sa, ib, ib + sa, std::equal_to<int>()) ==
+           (std::pair<int*,int*>(ia+3,ib+3)));
+    assert(std::mismatch(ia, ia + sa, ib, ib + 2, std::equal_to<int>()) ==
+           (std::pair<int*,int*>(ia+2,ib+2)));
+#endif
 }