[libc++][chrono] Adds year_month_day_last&::operator<=>.

[mordante]

41f7bb9 claimed it implemented this change but the code was not adjusted. The other spaceship operators in the calendar code have been validated too.

Implements parts of

• P1614R2 The Mothership has Landed

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Mark de Wever (mordante)

Changes

41f7bb9 claimed it implemented this change but the code was not adjusted. The other spaceship operators in the calendar code have been validated too.

Implements parts of

• P1614R2 The Mothership has Landed

---

Full diff: https://github.com/llvm/llvm-project/pull/98169.diff

2 Files Affected:

• (modified) libcxx/include/__chrono/year_month_day.h (+5-27)
• (modified) libcxx/test/std/time/time.cal/time.cal.ymdlast/time.cal.ymdlast.nonmembers/comparisons.pass.cpp (+60-67)

diff --git a/libcxx/include/__chrono/year_month_day.h b/libcxx/include/__chrono/year_month_day.h
index 75884f3654d87..b06c0be03e0de 100644
--- a/libcxx/include/__chrono/year_month_day.h
+++ b/libcxx/include/__chrono/year_month_day.h
@@ -239,33 +239,11 @@ operator==(const year_month_day_last& __lhs, const year_month_day_last& __rhs) n
   return __lhs.year() == __rhs.year() && __lhs.month_day_last() == __rhs.month_day_last();
 }
 
-_LIBCPP_HIDE_FROM_ABI inline constexpr bool
-operator!=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept {
-  return !(__lhs == __rhs);
-}
-
-_LIBCPP_HIDE_FROM_ABI inline constexpr bool
-operator<(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept {
-  if (__lhs.year() < __rhs.year())
-    return true;
-  if (__lhs.year() > __rhs.year())
-    return false;
-  return __lhs.month_day_last() < __rhs.month_day_last();
-}
-
-_LIBCPP_HIDE_FROM_ABI inline constexpr bool
-operator>(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept {
-  return __rhs < __lhs;
-}
-
-_LIBCPP_HIDE_FROM_ABI inline constexpr bool
-operator<=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept {
-  return !(__rhs < __lhs);
-}
-
-_LIBCPP_HIDE_FROM_ABI inline constexpr bool
-operator>=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept {
-  return !(__lhs < __rhs);
+_LIBCPP_HIDE_FROM_ABI inline constexpr strong_ordering
+operator<=>(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept {
+  if (auto __c = __lhs.year() <=> __rhs.year(); __c != 0)
+    return __c;
+  return __lhs.month_day_last() <=> __rhs.month_day_last();
 }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last operator/(const year_month& __lhs, last_spec) noexcept {
diff --git a/libcxx/test/std/time/time.cal/time.cal.ymdlast/time.cal.ymdlast.nonmembers/comparisons.pass.cpp b/libcxx/test/std/time/time.cal/time.cal.ymdlast/time.cal.ymdlast.nonmembers/comparisons.pass.cpp
index 45d7e51fbe718..e28b6d8609bc4 100644
--- a/libcxx/test/std/time/time.cal/time.cal.ymdlast/time.cal.ymdlast.nonmembers/comparisons.pass.cpp
+++ b/libcxx/test/std/time/time.cal/time.cal.ymdlast/time.cal.ymdlast.nonmembers/comparisons.pass.cpp
@@ -5,19 +5,14 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 
 // <chrono>
 // class year_month_day_last;
 
 // constexpr bool operator==(const year_month_day_last& x, const year_month_day_last& y) noexcept;
-//   Returns: x.year() == y.year() && x.month_day_last() == y.month_day_last().
-//
-// constexpr bool operator< (const year_month_day_last& x, const year_month_day_last& y) noexcept;
-//   Returns:
-//      If x.year() < y.year(), returns true.
-//      Otherwise, if x.year() > y.year(), returns false.
-//      Otherwise, returns x.month_day_last() < y.month_day_last()
+// constexpr bool operator<=>(const year_month_day_last& x, const year_month_day_last& y) noexcept;
 
 #include <chrono>
 #include <type_traits>
@@ -26,63 +21,61 @@
 #include "test_macros.h"
 #include "test_comparisons.h"
 
-int main(int, char**)
-{
-    using year                = std::chrono::year;
-    using month               = std::chrono::month;
-    using month_day_last      = std::chrono::month_day_last;
-    using year_month_day_last = std::chrono::year_month_day_last;
-
-    AssertComparisonsAreNoexcept<year_month_day_last>();
-    AssertComparisonsReturnBool<year_month_day_last>();
-
-    constexpr month January = std::chrono::January;
-    constexpr month February = std::chrono::February;
-
-    static_assert( testComparisons(
-        year_month_day_last{year{1234}, month_day_last{January}},
-        year_month_day_last{year{1234}, month_day_last{January}},
-        true, false), "");
-
-    // different month
-    static_assert( testComparisons(
-        year_month_day_last{year{1234}, month_day_last{January}},
-        year_month_day_last{year{1234}, month_day_last{February}},
-        false, true), "");
-
-    // different year
-    static_assert( testComparisons(
-        year_month_day_last{year{1234}, month_day_last{January}},
-        year_month_day_last{year{1235}, month_day_last{January}},
-        false, true), "");
-
-    // different month
-    static_assert( testComparisons(
-        year_month_day_last{year{1234}, month_day_last{January}},
-        year_month_day_last{year{1234}, month_day_last{February}},
-        false, true), "");
-
-    // different year and month
-    static_assert( testComparisons(
-        year_month_day_last{year{1234}, month_day_last{February}},
-        year_month_day_last{year{1235}, month_day_last{January}},
-        false, true), "");
-
-    // same year, different months
-    for (unsigned i = 1; i < 12; ++i)
-        for (unsigned j = 1; j < 12; ++j)
-            assert((testComparisons(
-                year_month_day_last{year{1234}, month_day_last{month{i}}},
-                year_month_day_last{year{1234}, month_day_last{month{j}}},
-                i == j, i < j )));
-
-    // same month, different years
-    for (int i = 1000; i < 2000; ++i)
-        for (int j = 1000; j < 2000; ++j)
-        assert((testComparisons(
-            year_month_day_last{year{i}, month_day_last{January}},
-            year_month_day_last{year{j}, month_day_last{January}},
-            i == j, i < j )));
-
-    return 0;
+constexpr bool test() {
+  using year                = std::chrono::year;
+  using month               = std::chrono::month;
+  using month_day_last      = std::chrono::month_day_last;
+  using year_month_day_last = std::chrono::year_month_day_last;
+
+  constexpr month January  = std::chrono::January;
+  constexpr month February = std::chrono::February;
+
+  assert(testOrder(year_month_day_last{year{1234}, month_day_last{January}},
+                   year_month_day_last{year{1234}, month_day_last{January}},
+                   std::strong_ordering::equal));
+
+  //  different month
+  assert(testOrder(year_month_day_last{year{1234}, month_day_last{January}},
+                   year_month_day_last{year{1234}, month_day_last{February}},
+                   std::strong_ordering::less));
+
+  //  different year
+  assert(testOrder(year_month_day_last{year{1234}, month_day_last{January}},
+                   year_month_day_last{year{1235}, month_day_last{January}},
+                   std::strong_ordering::less));
+
+  //  different year and month
+  assert(testOrder(year_month_day_last{year{1234}, month_day_last{February}},
+                   year_month_day_last{year{1235}, month_day_last{January}},
+                   std::strong_ordering::less));
+
+  //  same year, different months
+  for (unsigned i = 1; i < 12; ++i)
+    for (unsigned j = 1; j < 12; ++j)
+      assert((testOrder(year_month_day_last{year{1234}, month_day_last{month{i}}},
+                        year_month_day_last{year{1234}, month_day_last{month{j}}},
+                        i == j  ? std::strong_ordering::equal
+                        : i < j ? std::strong_ordering::less
+                                : std::strong_ordering::greater)));
+
+  //  same month, different years
+  for (int i = 1000; i < 20; ++i)
+    for (int j = 1000; j < 20; ++j)
+      assert((testOrder(year_month_day_last{year{i}, month_day_last{January}},
+                        year_month_day_last{year{j}, month_day_last{January}},
+                        i == j  ? std::strong_ordering::equal
+                        : i < j ? std::strong_ordering::less
+                                : std::strong_ordering::greater)));
+  return true;
+}
+
+int main(int, char**) {
+  using year_month_day_last = std::chrono::year_month_day_last;
+  AssertOrderAreNoexcept<year_month_day_last>();
+  AssertOrderReturn<std::strong_ordering, year_month_day_last>();
+
+  test();
+  static_assert(test());
+
+  return 0;
 }