First part of P0202: Adding constexpr modifiers to functions in <algorithm> and <utility>. This commit is all the is_XXX algorithms.

llvm-svn: 322489

2 files changed, 40 insertions, 2 deletions

diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation.pass.cpp
index e3f7c3cd87d..cde76d5ca06 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation.pass.cpp
@@ -10,7 +10,7 @@
 // <algorithm>
 
 // template<class ForwardIterator1, class ForwardIterator2>
-//   bool
+//   constexpr bool   // constexpr after C++17
 //   is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
 //                  ForwardIterator2 first2);
 
@@ -21,6 +21,21 @@
 
 #include "test_macros.h"
 
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR int test_constexpr() {
+    int ia[] = {0, 0, 0};
+    int ib[] = {1, 1, 0};
+    int ic[] = {1, 0, 1};
+    int id[] = {1};
+    return !std::is_permutation(std::begin(ia), std::end(ia), std::begin(ib))
+        && !std::is_permutation(std::begin(ia), std::end(ia), std::begin(ib), std::end(ib))
+        &&  std::is_permutation(std::begin(ib), std::end(ib), std::begin(ic))
+        &&  std::is_permutation(std::begin(ib), std::end(ib), std::begin(ic), std::end(ic))
+        && !std::is_permutation(std::begin(ic), std::end(ic), std::begin(id), std::end(id))
+        ;
+    }
+#endif
+
 int main()
 {
     {
@@ -600,4 +615,8 @@ int main()
                                    forward_iterator<const int*>(ib + sa)) == false);
 #endif
     }
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }
diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp
index 6e9cdaabd30..13129289629 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.is_permutation/is_permutation_pred.pass.cpp
@@ -10,7 +10,7 @@
 // <algorithm>
 
 // template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-//   bool
+//   constexpr bool   // constexpr after C++17
 //   is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
 //                  ForwardIterator2 first2, BinaryPredicate pred);
 
@@ -28,6 +28,21 @@ bool counting_equals ( const T &a, const T &b ) {
     return a == b;
     }
 
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR int test_constexpr() {
+    int ia[] = {0, 0, 0};
+    int ib[] = {1, 1, 0};
+    int ic[] = {1, 0, 1};
+    int id[] = {1};
+    std::equal_to<int> c;
+    return !std::is_permutation(std::begin(ia), std::end(ia), std::begin(ib)              , c)
+        && !std::is_permutation(std::begin(ia), std::end(ia), std::begin(ib), std::end(ib), c)
+        &&  std::is_permutation(std::begin(ib), std::end(ib), std::begin(ic)              , c)
+        &&  std::is_permutation(std::begin(ib), std::end(ib), std::begin(ic), std::end(ic), c)
+        && !std::is_permutation(std::begin(ic), std::end(ic), std::begin(id), std::end(id), c)
+        ;
+    }
+#endif
 
 int main()
 {
@@ -723,4 +738,8 @@ int main()
                                    std::equal_to<const int>()) == false);
 #endif
     }
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }