1 files changed, 62 insertions, 0 deletions
diff --git a/libcxx/test/std/utilities/time/time.cal/time.cal.year/time.cal.year.nonmembers/minus.pass.cpp b/libcxx/test/std/utilities/time/time.cal/time.cal.year/time.cal.year.nonmembers/minus.pass.cpp
new file mode 100644
index 00000000000..788b9589688
--- /dev/null
+++ b/libcxx/test/std/utilities/time/time.cal/time.cal.year/time.cal.year.nonmembers/minus.pass.cpp
@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <chrono>
+// class year;
+
+// constexpr year operator-(const year& x, const years& y) noexcept;
+//   Returns: x + -y.
+//
+// constexpr years operator-(const year& x, const year& y) noexcept;
+//   Returns: If x.ok() == true and y.ok() == true, returns a value m in the range 
+//   [years{0}, years{11}] satisfying y + m == x. 
+//   Otherwise the value returned is unspecified. 
+//   [Example: January - February == years{11}. —end example]
+
+extern "C" int printf(const char *, ...);
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+template <typename Y, typename Ys>
+constexpr bool testConstexpr()
+{
+    Y y{2313};
+    Ys offset{1006};
+    if (y - offset != Y{1307}) return false;
+    if (y - Y{1307} != offset) return false;
+    return true;
+}
+
+int main()
+{
+    using year  = std::chrono::year;
+    using years = std::chrono::years;
+
+    ASSERT_NOEXCEPT(                 std::declval<year>() - std::declval<years>());
+    ASSERT_SAME_TYPE(year , decltype(std::declval<year>() - std::declval<years>()));
+
+    ASSERT_NOEXCEPT(                 std::declval<year>() - std::declval<year>());
+    ASSERT_SAME_TYPE(years, decltype(std::declval<year>() - std::declval<year>()));
+    
+    static_assert(testConstexpr<year, years>(), "");
+
+    year y{1223};
+    for (int i = 1100; i <= 1110; ++i)
+    {
+        year  y1 = y - years{i};
+        years ys1 = y - year{i};
+        assert(static_cast<int>(y1) == 1223 - i);
+        assert(ys1.count()          == 1223 - i);
+    }
+}