1 files changed, 93 insertions, 0 deletions
diff --git a/test/std/utilities/time/time.cal/time.cal.ymwdlast/time.cal.ymwdlast.nonmembers/minus.pass.cpp b/test/std/utilities/time/time.cal/time.cal.ymwdlast/time.cal.ymwdlast.nonmembers/minus.pass.cpp
new file mode 100644
index 000000000000..c0ca34e83fcc
--- /dev/null
+++ b/test/std/utilities/time/time.cal/time.cal.ymwdlast/time.cal.ymwdlast.nonmembers/minus.pass.cpp
@@ -0,0 +1,93 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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++98, c++03, c++11, c++14, c++17
+
+// <chrono>
+// class year_month_weekday_last;
+
+// constexpr year_month_weekday_last operator-(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
+//   Returns: ymwdl + (-dm).
+//
+// constexpr year_month_weekday_last operator-(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
+//   Returns: ymwdl + (-dy).
+
+#include <chrono>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+#include <iostream>
+
+constexpr bool testConstexprYears(std::chrono::year_month_weekday_last ym)
+{
+    std::chrono::years offset{14};
+    if (static_cast<int>((ym         ).year()) != 66) return false;
+    if (static_cast<int>((ym - offset).year()) != 52) return false;
+    return true;
+}
+
+constexpr bool testConstexprMonths(std::chrono::year_month_weekday_last ym)
+{
+    std::chrono::months offset{6};
+    if (static_cast<unsigned>((ym         ).month()) != 10) return false;
+    if (static_cast<unsigned>((ym - offset).month()) !=  4) return false;
+    return true;
+}
+
+int main()
+{
+    using year                    = std::chrono::year;
+    using month                   = std::chrono::month;
+    using weekday                 = std::chrono::weekday;
+    using weekday_last            = std::chrono::weekday_last;
+    using year_month_weekday_last = std::chrono::year_month_weekday_last;
+    using years                   = std::chrono::years;
+    using months                  = std::chrono::months;
+
+    constexpr month October = std::chrono::October;
+    constexpr weekday Tuesday = std::chrono::Tuesday;
+
+    { // year_month_weekday_last - years
+
+    ASSERT_NOEXCEPT(                                   std::declval<year_month_weekday_last>() - std::declval<years>());
+    ASSERT_SAME_TYPE(year_month_weekday_last, decltype(std::declval<year_month_weekday_last>() - std::declval<years>()));
+
+    static_assert(testConstexprYears(year_month_weekday_last{year{66}, October, weekday_last{Tuesday}}), "");
+
+    year_month_weekday_last ym{year{1234}, October, weekday_last{Tuesday}};
+    for (int i = 0; i <= 10; ++i)
+    {
+        year_month_weekday_last ym1 = ym - years{i};
+        assert(ym1.year()         == year{1234 - i});
+        assert(ym1.month()        == October);
+        assert(ym1.weekday()      == Tuesday);
+        assert(ym1.weekday_last() == weekday_last{Tuesday});
+    }
+    }
+
+    { // year_month_weekday_last - months
+
+    ASSERT_NOEXCEPT(                                   std::declval<year_month_weekday_last>() - std::declval<months>());
+    ASSERT_SAME_TYPE(year_month_weekday_last, decltype(std::declval<year_month_weekday_last>() - std::declval<months>()));
+
+    static_assert(testConstexprMonths(year_month_weekday_last{year{66}, October, weekday_last{Tuesday}}), "");
+
+    year_month_weekday_last ym{year{1234}, October, weekday_last{Tuesday}};
+    for (unsigned i = 0; i < 10; ++i)
+    {
+        year_month_weekday_last ym1 = ym - months{i};
+        assert(ym1.year()         == year{1234});
+        assert(ym1.month()        == month{10 - i});
+        assert(ym1.weekday()      == Tuesday);
+        assert(ym1.weekday_last() == weekday_last{Tuesday});
+    }
+    }
+
+}