[libcxx-commits] [libcxx] [libc++] Add missing C++20 [time.point.arithmetic] (PR #143165)

via libcxx-commits libcxx-commits at lists.llvm.org
Mon Jun 9 11:51:11 PDT 2025


https://github.com/maflcko updated https://github.com/llvm/llvm-project/pull/143165

>From edd6ada2992c7f2975767d1e2a54eea04fe1d5dd Mon Sep 17 00:00:00 2001
From: MarcoFalke <*~=`'#}+{/-|&$^_ at 721217.xyz>
Date: Fri, 6 Jun 2025 17:41:08 +0200
Subject: [PATCH 1/3] [libc++] Add missing C++20 [time.point.arithmetic]

---
 libcxx/include/__chrono/time_point.h          | 13 ++++++
 libcxx/include/chrono                         |  5 +++
 .../time.point.arithmetic/op_++.pass.cpp      | 39 ++++++++++++++++++
 .../time.point.arithmetic/op_++int.pass.cpp   | 40 +++++++++++++++++++
 .../time.point.arithmetic/op_--.pass.cpp      | 39 ++++++++++++++++++
 .../time.point.arithmetic/op_--int.pass.cpp   | 40 +++++++++++++++++++
 6 files changed, 176 insertions(+)
 create mode 100644 libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
 create mode 100644 libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
 create mode 100644 libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
 create mode 100644 libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp

diff --git a/libcxx/include/__chrono/time_point.h b/libcxx/include/__chrono/time_point.h
index 6b866b882f89a..36be0759b6b8c 100644
--- a/libcxx/include/__chrono/time_point.h
+++ b/libcxx/include/__chrono/time_point.h
@@ -58,6 +58,19 @@ class time_point {
 
   // arithmetic
 
+#if _LIBCPP_STD_VER >= 20
+  _LIBCPP_HIDE_FROM_ABI constexpr time_point& operator++() {
+    ++__d_;
+    return *this;
+  }
+  _LIBCPP_HIDE_FROM_ABI constexpr time_point operator++(int) { return time_point(__d_++); }
+  _LIBCPP_HIDE_FROM_ABI constexpr time_point& operator--() {
+    --__d_;
+    return *this;
+  }
+  _LIBCPP_HIDE_FROM_ABI constexpr time_point operator--(int) { return time_point(__d_--); }
+#endif // _LIBCPP_STD_VER >= 20
+
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 time_point& operator+=(const duration& __d) {
     __d_ += __d;
     return *this;
diff --git a/libcxx/include/chrono b/libcxx/include/chrono
index cd9b98872083e..82e99a31bcc9f 100644
--- a/libcxx/include/chrono
+++ b/libcxx/include/chrono
@@ -132,6 +132,11 @@ public:
 
     // arithmetic
 
+    constexpr time_point& operator++();    // C++20
+    constexpr time_point  operator++(int); // C++20
+    constexpr time_point& operator--();    // C++20
+    constexpr time_point  operator--(int); // C++20
+
     time_point& operator+=(const duration& d); // constexpr in C++17
     time_point& operator-=(const duration& d); // constexpr in C++17
 
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
new file mode 100644
index 0000000000000..dad50d09ed8b0
--- /dev/null
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <chrono>
+
+// time_point
+
+// constexpr time_point& operator++();
+
+#include <chrono>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool constexpr_test() {
+  typedef std::chrono::system_clock Clock;
+  typedef std::chrono::milliseconds Duration;
+  std::chrono::time_point<Clock, Duration> t(Duration(5));
+  return (++t).time_since_epoch() == Duration(6);
+}
+
+int main(int, char**) {
+  typedef std::chrono::system_clock Clock;
+  typedef std::chrono::milliseconds Duration;
+  std::chrono::time_point<Clock, Duration> t(Duration(3));
+  std::chrono::time_point<Clock, Duration>& tref = ++t;
+  assert(&tref == &t);
+  assert(t.time_since_epoch() == Duration(4));
+
+  static_assert(constexpr_test());
+
+  return 0;
+}
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
new file mode 100644
index 0000000000000..c517ff9516bdc
--- /dev/null
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
@@ -0,0 +1,40 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <chrono>
+
+// time_point
+
+// constexpr time_point operator++(int);
+
+#include <chrono>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool test_constexpr() {
+  typedef std::chrono::system_clock Clock;
+  typedef std::chrono::milliseconds Duration;
+  std::chrono::time_point<Clock, Duration> t1(Duration(3));
+  std::chrono::time_point<Clock, Duration> t2 = t1++;
+  return t1.time_since_epoch() == Duration(4) && t2.time_since_epoch() == Duration(3);
+}
+
+int main(int, char**) {
+  typedef std::chrono::system_clock Clock;
+  typedef std::chrono::milliseconds Duration;
+  std::chrono::time_point<Clock, Duration> t1(Duration(3));
+  std::chrono::time_point<Clock, Duration> t2 = t1++;
+  assert(t1.time_since_epoch() == Duration(4));
+  assert(t2.time_since_epoch() == Duration(3));
+
+  static_assert(test_constexpr());
+
+  return 0;
+}
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
new file mode 100644
index 0000000000000..7b55f747d06c7
--- /dev/null
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <chrono>
+
+// time_point
+
+// constexpr time_point& operator--();
+
+#include <chrono>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool constexpr_test() {
+  typedef std::chrono::system_clock Clock;
+  typedef std::chrono::milliseconds Duration;
+  std::chrono::time_point<Clock, Duration> t(Duration(5));
+  return (--t).time_since_epoch() == Duration(4);
+}
+
+int main(int, char**) {
+  typedef std::chrono::system_clock Clock;
+  typedef std::chrono::milliseconds Duration;
+  std::chrono::time_point<Clock, Duration> t(Duration(3));
+  std::chrono::time_point<Clock, Duration>& tref = --t;
+  assert(&tref == &t);
+  assert(t.time_since_epoch() == Duration(2));
+
+  static_assert(constexpr_test());
+
+  return 0;
+}
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp
new file mode 100644
index 0000000000000..6dfa03c154f57
--- /dev/null
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp
@@ -0,0 +1,40 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// <chrono>
+
+// time_point
+
+// constexpr time_point operator--(int);
+
+#include <chrono>
+#include <cassert>
+
+#include "test_macros.h"
+
+constexpr bool test_constexpr() {
+  typedef std::chrono::system_clock Clock;
+  typedef std::chrono::milliseconds Duration;
+  std::chrono::time_point<Clock, Duration> t1(Duration(3));
+  std::chrono::time_point<Clock, Duration> t2 = t1--;
+  return t1.time_since_epoch() == Duration(2) && t2.time_since_epoch() == Duration(3);
+}
+
+int main(int, char**) {
+  typedef std::chrono::system_clock Clock;
+  typedef std::chrono::milliseconds Duration;
+  std::chrono::time_point<Clock, Duration> t1(Duration(3));
+  std::chrono::time_point<Clock, Duration> t2 = t1--;
+  assert(t1.time_since_epoch() == Duration(2));
+  assert(t2.time_since_epoch() == Duration(3));
+
+  static_assert(test_constexpr());
+
+  return 0;
+}

>From 9980f08a9c99cfbe45fe05b2dcf44de4f10eb10f Mon Sep 17 00:00:00 2001
From: MarcoFalke <*~=`'#}+{/-|&$^_ at 721217.xyz>
Date: Mon, 9 Jun 2025 14:57:03 +0200
Subject: [PATCH 2/3] test_fixups

---
 .../time.point.arithmetic/op_++.pass.cpp      | 22 +++++++-----------
 .../time.point.arithmetic/op_++int.pass.cpp   | 23 +++++++------------
 .../time.point.arithmetic/op_--.pass.cpp      | 22 +++++++-----------
 .../time.point.arithmetic/op_--int.pass.cpp   | 23 +++++++------------
 4 files changed, 32 insertions(+), 58 deletions(-)

diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
index dad50d09ed8b0..1ccf4d13c13c1 100644
--- a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
@@ -5,7 +5,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-// UNSUPPORTED: c++03, c++11, c++14, c++17
+// REQUIRES: std-at-least-c++20
 
 // <chrono>
 
@@ -13,27 +13,21 @@
 
 // constexpr time_point& operator++();
 
-#include <chrono>
 #include <cassert>
+#include <chrono>
 
 #include "test_macros.h"
 
-constexpr bool constexpr_test() {
+constexpr bool test() {
   typedef std::chrono::system_clock Clock;
   typedef std::chrono::milliseconds Duration;
-  std::chrono::time_point<Clock, Duration> t(Duration(5));
-  return (++t).time_since_epoch() == Duration(6);
+  std::chrono::time_point<Clock, Duration> t{Duration{5}};
+  std::chrono::time_point<Clock, Duration>& tref{++t};
+  return &tref == &t && tref.time_since_epoch() == Duration{6};
 }
 
 int main(int, char**) {
-  typedef std::chrono::system_clock Clock;
-  typedef std::chrono::milliseconds Duration;
-  std::chrono::time_point<Clock, Duration> t(Duration(3));
-  std::chrono::time_point<Clock, Duration>& tref = ++t;
-  assert(&tref == &t);
-  assert(t.time_since_epoch() == Duration(4));
-
-  static_assert(constexpr_test());
-
+  assert(test());
+  static_assert(test());
   return 0;
 }
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
index c517ff9516bdc..670a7b5b67889 100644
--- a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
@@ -5,7 +5,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-// UNSUPPORTED: c++03, c++11, c++14, c++17
+// REQUIRES: std-at-least-c++20
 
 // <chrono>
 
@@ -13,28 +13,21 @@
 
 // constexpr time_point operator++(int);
 
-#include <chrono>
 #include <cassert>
+#include <chrono>
 
 #include "test_macros.h"
 
-constexpr bool test_constexpr() {
+constexpr bool test() {
   typedef std::chrono::system_clock Clock;
   typedef std::chrono::milliseconds Duration;
-  std::chrono::time_point<Clock, Duration> t1(Duration(3));
-  std::chrono::time_point<Clock, Duration> t2 = t1++;
-  return t1.time_since_epoch() == Duration(4) && t2.time_since_epoch() == Duration(3);
+  std::chrono::time_point<Clock, Duration> t1{Duration{3}};
+  std::chrono::time_point<Clock, Duration> t2{t1++};
+  return t1.time_since_epoch() == Duration{4} && t2.time_since_epoch() == Duration{3};
 }
 
 int main(int, char**) {
-  typedef std::chrono::system_clock Clock;
-  typedef std::chrono::milliseconds Duration;
-  std::chrono::time_point<Clock, Duration> t1(Duration(3));
-  std::chrono::time_point<Clock, Duration> t2 = t1++;
-  assert(t1.time_since_epoch() == Duration(4));
-  assert(t2.time_since_epoch() == Duration(3));
-
-  static_assert(test_constexpr());
-
+  assert(test());
+  static_assert(test());
   return 0;
 }
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
index 7b55f747d06c7..0a28b536acae9 100644
--- a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
@@ -5,7 +5,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-// UNSUPPORTED: c++03, c++11, c++14, c++17
+// REQUIRES: std-at-least-c++20
 
 // <chrono>
 
@@ -13,27 +13,21 @@
 
 // constexpr time_point& operator--();
 
-#include <chrono>
 #include <cassert>
+#include <chrono>
 
 #include "test_macros.h"
 
-constexpr bool constexpr_test() {
+constexpr bool test() {
   typedef std::chrono::system_clock Clock;
   typedef std::chrono::milliseconds Duration;
-  std::chrono::time_point<Clock, Duration> t(Duration(5));
-  return (--t).time_since_epoch() == Duration(4);
+  std::chrono::time_point<Clock, Duration> t{Duration{5}};
+  std::chrono::time_point<Clock, Duration>& tref{--t};
+  return &tref == &t && tref.time_since_epoch() == Duration{4};
 }
 
 int main(int, char**) {
-  typedef std::chrono::system_clock Clock;
-  typedef std::chrono::milliseconds Duration;
-  std::chrono::time_point<Clock, Duration> t(Duration(3));
-  std::chrono::time_point<Clock, Duration>& tref = --t;
-  assert(&tref == &t);
-  assert(t.time_since_epoch() == Duration(2));
-
-  static_assert(constexpr_test());
-
+  assert(test());
+  static_assert(test());
   return 0;
 }
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp
index 6dfa03c154f57..c2eafd715bc40 100644
--- a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp
@@ -5,7 +5,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-// UNSUPPORTED: c++03, c++11, c++14, c++17
+// REQUIRES: std-at-least-c++20
 
 // <chrono>
 
@@ -13,28 +13,21 @@
 
 // constexpr time_point operator--(int);
 
-#include <chrono>
 #include <cassert>
+#include <chrono>
 
 #include "test_macros.h"
 
-constexpr bool test_constexpr() {
+constexpr bool test() {
   typedef std::chrono::system_clock Clock;
   typedef std::chrono::milliseconds Duration;
-  std::chrono::time_point<Clock, Duration> t1(Duration(3));
-  std::chrono::time_point<Clock, Duration> t2 = t1--;
-  return t1.time_since_epoch() == Duration(2) && t2.time_since_epoch() == Duration(3);
+  std::chrono::time_point<Clock, Duration> t1{Duration{3}};
+  std::chrono::time_point<Clock, Duration> t2{t1--};
+  return t1.time_since_epoch() == Duration{2} && t2.time_since_epoch() == Duration{3};
 }
 
 int main(int, char**) {
-  typedef std::chrono::system_clock Clock;
-  typedef std::chrono::milliseconds Duration;
-  std::chrono::time_point<Clock, Duration> t1(Duration(3));
-  std::chrono::time_point<Clock, Duration> t2 = t1--;
-  assert(t1.time_since_epoch() == Duration(2));
-  assert(t2.time_since_epoch() == Duration(3));
-
-  static_assert(test_constexpr());
-
+  assert(test());
+  static_assert(test());
   return 0;
 }

>From 07cb87c69351fb3c55c872a97662cf21600b4fa0 Mon Sep 17 00:00:00 2001
From: MarcoFalke <*~=`'#}+{/-|&$^_ at 721217.xyz>
Date: Mon, 9 Jun 2025 20:50:34 +0200
Subject: [PATCH 3/3] test_fixups_2

---
 .../time/time.point/time.point.arithmetic/op_++.pass.cpp  | 8 +++++---
 .../time.point/time.point.arithmetic/op_++int.pass.cpp    | 8 +++++---
 .../time/time.point/time.point.arithmetic/op_--.pass.cpp  | 8 +++++---
 .../time.point/time.point.arithmetic/op_--int.pass.cpp    | 8 +++++---
 4 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
index 1ccf4d13c13c1..bcc8011c07d2e 100644
--- a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++.pass.cpp
@@ -19,11 +19,13 @@
 #include "test_macros.h"
 
 constexpr bool test() {
-  typedef std::chrono::system_clock Clock;
-  typedef std::chrono::milliseconds Duration;
+  using Clock    = std::chrono::system_clock;
+  using Duration = std::chrono::milliseconds;
   std::chrono::time_point<Clock, Duration> t{Duration{5}};
   std::chrono::time_point<Clock, Duration>& tref{++t};
-  return &tref == &t && tref.time_since_epoch() == Duration{6};
+  assert(&tref == &t);
+  assert(tref.time_since_epoch() == Duration{6});
+  return true;
 }
 
 int main(int, char**) {
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
index 670a7b5b67889..6794c0b6773d6 100644
--- a/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_++int.pass.cpp
@@ -19,11 +19,13 @@
 #include "test_macros.h"
 
 constexpr bool test() {
-  typedef std::chrono::system_clock Clock;
-  typedef std::chrono::milliseconds Duration;
+  using Clock    = std::chrono::system_clock;
+  using Duration = std::chrono::milliseconds;
   std::chrono::time_point<Clock, Duration> t1{Duration{3}};
   std::chrono::time_point<Clock, Duration> t2{t1++};
-  return t1.time_since_epoch() == Duration{4} && t2.time_since_epoch() == Duration{3};
+  assert(t1.time_since_epoch() == Duration{4});
+  assert(t2.time_since_epoch() == Duration{3});
+  return true;
 }
 
 int main(int, char**) {
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
index 0a28b536acae9..c0198d2457824 100644
--- a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--.pass.cpp
@@ -19,11 +19,13 @@
 #include "test_macros.h"
 
 constexpr bool test() {
-  typedef std::chrono::system_clock Clock;
-  typedef std::chrono::milliseconds Duration;
+  using Clock    = std::chrono::system_clock;
+  using Duration = std::chrono::milliseconds;
   std::chrono::time_point<Clock, Duration> t{Duration{5}};
   std::chrono::time_point<Clock, Duration>& tref{--t};
-  return &tref == &t && tref.time_since_epoch() == Duration{4};
+  assert(&tref == &t);
+  assert(tref.time_since_epoch() == Duration{4});
+  return true;
 }
 
 int main(int, char**) {
diff --git a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp
index c2eafd715bc40..7e3edc380f9c1 100644
--- a/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp
+++ b/libcxx/test/std/time/time.point/time.point.arithmetic/op_--int.pass.cpp
@@ -19,11 +19,13 @@
 #include "test_macros.h"
 
 constexpr bool test() {
-  typedef std::chrono::system_clock Clock;
-  typedef std::chrono::milliseconds Duration;
+  using Clock    = std::chrono::system_clock;
+  using Duration = std::chrono::milliseconds;
   std::chrono::time_point<Clock, Duration> t1{Duration{3}};
   std::chrono::time_point<Clock, Duration> t2{t1--};
-  return t1.time_since_epoch() == Duration{2} && t2.time_since_epoch() == Duration{3};
+  assert(t1.time_since_epoch() == Duration{2});
+  assert(t2.time_since_epoch() == Duration{3});
+  return true;
 }
 
 int main(int, char**) {



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