More constexpr (re P0202) - equal and mismatch

llvm-svn: 322527

1 files changed, 35 insertions, 1 deletions

diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.equal/equal_pred.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.equal/equal_pred.pass.cpp
index d57e365a919..53f52e0e370 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.equal/equal_pred.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.equal/equal_pred.pass.cpp
@@ -12,8 +12,16 @@
 // template<InputIterator Iter1, InputIterator Iter2,
 //          Predicate<auto, Iter1::value_type, Iter2::value_type> Pred>
 //   requires CopyConstructible<Pred>
-//   bool
+//   constexpr bool     // constexpr after c++17
 //   equal(Iter1 first1, Iter1 last1, Iter2 first2, Pred pred);
+//
+//	Introduced in C++14:
+// template<InputIterator Iter1, InputIterator Iter2,
+//          Predicate<auto, Iter1::value_type, Iter2::value_type> Pred>
+//   requires CopyConstructible<Pred>
+//   constexpr bool     // constexpr after c++17
+//   equal(Iter1 first1, Iter1 last1, Iter2 first2, Iter2 last2, Pred pred);
+
 
 #include <algorithm>
 #include <functional>
@@ -22,6 +30,28 @@
 #include "test_macros.h"
 #include "test_iterators.h"
 
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR bool eq(int a, int b) { return a == b; }
+
+TEST_CONSTEXPR bool test_constexpr() {
+    int ia[] = {1, 3, 6, 7};
+    int ib[] = {1, 3};
+    int ic[] = {1, 3, 5, 7};
+    typedef input_iterator<int*>         II;
+    typedef bidirectional_iterator<int*> BI;
+
+    return !std::equal(std::begin(ia), std::end(ia), std::begin(ic)              , eq)
+        && !std::equal(std::begin(ia), std::end(ia), std::begin(ic), std::end(ic), eq)
+        &&  std::equal(std::begin(ib), std::end(ib), std::begin(ic)              , eq)
+        && !std::equal(std::begin(ib), std::end(ib), std::begin(ic), std::end(ic), eq)
+
+        &&  std::equal(II(std::begin(ib)), II(std::end(ib)), II(std::begin(ic))                  , eq)
+        && !std::equal(BI(std::begin(ib)), BI(std::end(ib)), BI(std::begin(ic)), BI(std::end(ic)), eq)
+        ;
+    }
+#endif
+
+
 int comparison_count = 0;
 template <typename T>
 bool counting_equals ( const T &a, const T &b ) {
@@ -81,4 +111,8 @@ int main()
                        random_access_iterator<const int*>(ib+s),
                        std::equal_to<int>()));
 #endif
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }