[libcxx-commits] [libcxx] [libc++] LWG3260: year_month* arithmetic rejects durations convertible to years (PR #196384)
via libcxx-commits
libcxx-commits at lists.llvm.org
Thu May 7 23:41:54 PDT 2026
https://github.com/Skyfrei updated https://github.com/llvm/llvm-project/pull/196384
>From 703254776e26e70918d01110a7e2072d0af6f185 Mon Sep 17 00:00:00 2001
From: Skyfrei <tarkaklavio at gmail.com>
Date: Thu, 7 May 2026 19:58:40 +0200
Subject: [PATCH 1/4] operator overload for diffs
---
libcxx/include/__chrono/year_month_weekday.h | 28 +++++++++++------
libcxx/test/std/chrono/arithmetic.pass.cpp | 33 ++++++++++++++++++++
2 files changed, 51 insertions(+), 10 deletions(-)
create mode 100644 libcxx/test/std/chrono/arithmetic.pass.cpp
diff --git a/libcxx/include/__chrono/year_month_weekday.h b/libcxx/include/__chrono/year_month_weekday.h
index eff472ffcc8a8..6b90ec1d97818 100644
--- a/libcxx/include/__chrono/year_month_weekday.h
+++ b/libcxx/include/__chrono/year_month_weekday.h
@@ -49,7 +49,9 @@ class year_month_weekday {
: year_month_weekday(__from_days(__sysd.time_since_epoch())) {}
_LIBCPP_HIDE_FROM_ABI inline explicit constexpr year_month_weekday(const local_days& __locd) noexcept
: year_month_weekday(__from_days(__locd.time_since_epoch())) {}
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator+=(const months&) noexcept;
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator-=(const months&) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator+=(const years&) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator-=(const years&) noexcept;
@@ -125,17 +127,17 @@ operator/(const month_weekday& __lhs, int __rhs) noexcept {
return year(__rhs) / __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
operator+(const year_month_weekday& __lhs, const months& __rhs) noexcept {
return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_indexed();
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
operator+(const months& __lhs, const year_month_weekday& __rhs) noexcept {
return __rhs + __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
operator-(const year_month_weekday& __lhs, const months& __rhs) noexcept {
return __lhs + (-__rhs);
}
@@ -155,11 +157,13 @@ operator-(const year_month_weekday& __lhs, const years& __rhs) noexcept {
return __lhs + (-__rhs);
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept {
+template<class>
+[[nodiscard]]_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator-=(const months& __dm) noexcept {
+template<class>
+[[nodiscard]]_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
}
@@ -182,7 +186,9 @@ class year_month_weekday_last {
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last(
const chrono::year& __yval, const chrono::month& __mval, const chrono::weekday_last& __wdlval) noexcept
: __y_{__yval}, __m_{__mval}, __wdl_{__wdlval} {}
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator+=(const months& __dm) noexcept;
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator-=(const months& __dm) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator+=(const years& __dy) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator-=(const years& __dy) noexcept;
@@ -241,17 +247,17 @@ operator/(const month_weekday_last& __lhs, int __rhs) noexcept {
return year(__rhs) / __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
operator+(const year_month_weekday_last& __lhs, const months& __rhs) noexcept {
return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_last();
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
operator+(const months& __lhs, const year_month_weekday_last& __rhs) noexcept {
return __rhs + __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
operator-(const year_month_weekday_last& __lhs, const months& __rhs) noexcept {
return __lhs + (-__rhs);
}
@@ -271,12 +277,14 @@ operator-(const year_month_weekday_last& __lhs, const years& __rhs) noexcept {
return __lhs + (-__rhs);
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last&
+template<class>
+[[nodiscard]]_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last&
year_month_weekday_last::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last&
+template<class>
+[[nodiscard]]_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last&
year_month_weekday_last::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
diff --git a/libcxx/test/std/chrono/arithmetic.pass.cpp b/libcxx/test/std/chrono/arithmetic.pass.cpp
new file mode 100644
index 0000000000000..a8351f5b9c35c
--- /dev/null
+++ b/libcxx/test/std/chrono/arithmetic.pass.cpp
@@ -0,0 +1,33 @@
+#include <chrono>
+
+using namespace std::chrono;
+
+constexpr bool test_month() {
+ using decamonths = duration<int, std::ratio_multiply<std::ratio<10>, months::period>>;
+ auto ymd = 2001y/January/1d;
+ auto ymd2 = 2001y/January/1d;
+ ymd2 += std::chrono::duration_cast<std::chrono::months>(decamonths(1));
+ ymd += decamonths(1);
+
+
+ if (ymd2.month() != November)
+ return false;
+
+ return ymd == 2001y/November/1d;
+}
+
+constexpr bool test_year() {
+ using decades = duration<int, std::ratio_multiply<std::ratio<10>, years::period>>;
+ auto ymd = 2001y/January/1d;
+
+ ymd += duration_cast<years>(decades(1));
+
+ return ymd == 2011y/January/1d;
+}
+
+int main(int, char**) {
+ static_assert(test_month(), "Month arithmetic failed");
+ static_assert(test_year(), "Year arithmetic failed");
+
+ return 0;
+}
>From 5f7998ed1832a54c81331fbff3680aff98baee9e Mon Sep 17 00:00:00 2001
From: Skyfrei <tarkaklavio at gmail.com>
Date: Thu, 7 May 2026 20:23:32 +0200
Subject: [PATCH 2/4] fixed
---
libcxx/include/__chrono/year_month_day.h | 26 ++++++++++--------
libcxx/include/__chrono/year_month_weekday.h | 28 +++++++-------------
libcxx/test/std/chrono/arithmetic.pass.cpp | 10 ++++++-
3 files changed, 34 insertions(+), 30 deletions(-)
diff --git a/libcxx/include/__chrono/year_month_day.h b/libcxx/include/__chrono/year_month_day.h
index b0149d3ee1a37..3c79cb7d50a5e 100644
--- a/libcxx/include/__chrono/year_month_day.h
+++ b/libcxx/include/__chrono/year_month_day.h
@@ -54,7 +54,9 @@ class year_month_day {
_LIBCPP_HIDE_FROM_ABI inline explicit constexpr year_month_day(const local_days& __locd) noexcept
: year_month_day(__from_days(__locd.time_since_epoch())) {}
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day& operator+=(const months& __dm) noexcept;
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day& operator-=(const months& __dm) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day& operator+=(const years& __dy) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day& operator-=(const years& __dy) noexcept;
@@ -149,17 +151,17 @@ operator/(const month_day& __lhs, int __rhs) noexcept {
return year(__rhs) / __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
operator+(const year_month_day& __lhs, const months& __rhs) noexcept {
return (__lhs.year() / __lhs.month() + __rhs) / __lhs.day();
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
operator+(const months& __lhs, const year_month_day& __rhs) noexcept {
return __rhs + __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
operator-(const year_month_day& __lhs, const months& __rhs) noexcept {
return __lhs + -__rhs;
}
@@ -179,11 +181,11 @@ operator-(const year_month_day& __lhs, const years& __rhs) noexcept {
return __lhs + -__rhs;
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept {
+template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator-=(const months& __dm) noexcept {
+template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
}
@@ -204,8 +206,10 @@ class year_month_day_last {
public:
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last(const year& __yval, const month_day_last& __mdlval) noexcept
: __y_{__yval}, __mdl_{__mdlval} {}
-
+
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator+=(const months& __m) noexcept;
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator-=(const months& __m) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator+=(const years& __y) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator-=(const years& __y) noexcept;
@@ -281,17 +285,17 @@ operator/(const month_day_last& __lhs, int __rhs) noexcept {
return year{__rhs} / __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
operator+(const year_month_day_last& __lhs, const months& __rhs) noexcept {
return (__lhs.year() / __lhs.month() + __rhs) / last;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
operator+(const months& __lhs, const year_month_day_last& __rhs) noexcept {
return __rhs + __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
operator-(const year_month_day_last& __lhs, const months& __rhs) noexcept {
return __lhs + (-__rhs);
}
@@ -311,12 +315,12 @@ operator-(const year_month_day_last& __lhs, const years& __rhs) noexcept {
return __lhs + (-__rhs);
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last&
+template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last&
year_month_day_last::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last&
+template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last&
year_month_day_last::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
diff --git a/libcxx/include/__chrono/year_month_weekday.h b/libcxx/include/__chrono/year_month_weekday.h
index 6b90ec1d97818..eff472ffcc8a8 100644
--- a/libcxx/include/__chrono/year_month_weekday.h
+++ b/libcxx/include/__chrono/year_month_weekday.h
@@ -49,9 +49,7 @@ class year_month_weekday {
: year_month_weekday(__from_days(__sysd.time_since_epoch())) {}
_LIBCPP_HIDE_FROM_ABI inline explicit constexpr year_month_weekday(const local_days& __locd) noexcept
: year_month_weekday(__from_days(__locd.time_since_epoch())) {}
- template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator+=(const months&) noexcept;
- template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator-=(const months&) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator+=(const years&) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator-=(const years&) noexcept;
@@ -127,17 +125,17 @@ operator/(const month_weekday& __lhs, int __rhs) noexcept {
return year(__rhs) / __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
operator+(const year_month_weekday& __lhs, const months& __rhs) noexcept {
return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_indexed();
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
operator+(const months& __lhs, const year_month_weekday& __rhs) noexcept {
return __rhs + __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday
operator-(const year_month_weekday& __lhs, const months& __rhs) noexcept {
return __lhs + (-__rhs);
}
@@ -157,13 +155,11 @@ operator-(const year_month_weekday& __lhs, const years& __rhs) noexcept {
return __lhs + (-__rhs);
}
-template<class>
-[[nodiscard]]_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept {
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-template<class>
-[[nodiscard]]_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator-=(const months& __dm) noexcept {
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
}
@@ -186,9 +182,7 @@ class year_month_weekday_last {
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last(
const chrono::year& __yval, const chrono::month& __mval, const chrono::weekday_last& __wdlval) noexcept
: __y_{__yval}, __m_{__mval}, __wdl_{__wdlval} {}
- template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator+=(const months& __dm) noexcept;
- template<class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator-=(const months& __dm) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator+=(const years& __dy) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator-=(const years& __dy) noexcept;
@@ -247,17 +241,17 @@ operator/(const month_weekday_last& __lhs, int __rhs) noexcept {
return year(__rhs) / __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
operator+(const year_month_weekday_last& __lhs, const months& __rhs) noexcept {
return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_last();
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
operator+(const months& __lhs, const year_month_weekday_last& __rhs) noexcept {
return __rhs + __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last
operator-(const year_month_weekday_last& __lhs, const months& __rhs) noexcept {
return __lhs + (-__rhs);
}
@@ -277,14 +271,12 @@ operator-(const year_month_weekday_last& __lhs, const years& __rhs) noexcept {
return __lhs + (-__rhs);
}
-template<class>
-[[nodiscard]]_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last&
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last&
year_month_weekday_last::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-template<class>
-[[nodiscard]]_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last&
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday_last&
year_month_weekday_last::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
diff --git a/libcxx/test/std/chrono/arithmetic.pass.cpp b/libcxx/test/std/chrono/arithmetic.pass.cpp
index a8351f5b9c35c..f1b5d3946fa1c 100644
--- a/libcxx/test/std/chrono/arithmetic.pass.cpp
+++ b/libcxx/test/std/chrono/arithmetic.pass.cpp
@@ -25,9 +25,17 @@ constexpr bool test_year() {
return ymd == 2011y/January/1d;
}
+constexpr bool doc_ambig_test(){
+ using decades = duration<int, std::ratio_multiply<std::ratio<10>, years::period>>;
+ auto ymd = 2001y/January/1d;
+ ymd += decades(1);
+ return true;
+}
+
int main(int, char**) {
static_assert(test_month(), "Month arithmetic failed");
static_assert(test_year(), "Year arithmetic failed");
-
+ static_assert(doc_ambig_test(), "Doc");
+
return 0;
}
>From afcdef4bca90127ccebd5bf95f1c6664a584cc60 Mon Sep 17 00:00:00 2001
From: Skyfrei <tarkaklavio at gmail.com>
Date: Thu, 7 May 2026 20:37:56 +0200
Subject: [PATCH 3/4] added year_month as well
---
libcxx/include/__chrono/year_month.h | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/libcxx/include/__chrono/year_month.h b/libcxx/include/__chrono/year_month.h
index fdeeed1f386f8..04dc9b595b3e9 100644
--- a/libcxx/include/__chrono/year_month.h
+++ b/libcxx/include/__chrono/year_month.h
@@ -38,7 +38,9 @@ class year_month {
: __y_{__yval}, __m_{__mval} {}
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year year() const noexcept { return __y_; }
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m_; }
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator+=(const months& __dm) noexcept;
+ template<class = void>
_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator-=(const months& __dm) noexcept;
_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator+=(const years& __dy) noexcept;
_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator-=(const years& __dy) noexcept;
@@ -64,7 +66,7 @@ operator<=>(const year_month& __lhs, const year_month& __rhs) noexcept {
return __lhs.month() <=> __rhs.month();
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
operator+(const year_month& __lhs, const months& __rhs) noexcept {
int __dmi = static_cast<int>(static_cast<unsigned>(__lhs.month())) - 1 + __rhs.count();
const int __dy = (__dmi >= 0 ? __dmi : __dmi - 11) / 12;
@@ -72,7 +74,7 @@ operator+(const year_month& __lhs, const months& __rhs) noexcept {
return (__lhs.year() + years(__dy)) / month(static_cast<unsigned>(__dmi));
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
operator+(const months& __lhs, const year_month& __rhs) noexcept {
return __rhs + __lhs;
}
@@ -87,13 +89,13 @@ operator+(const years& __lhs, const year_month& __rhs) noexcept {
return __rhs + __lhs;
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr months
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr months
operator-(const year_month& __lhs, const year_month& __rhs) noexcept {
return (__lhs.year() - __rhs.year()) +
months(static_cast<unsigned>(__lhs.month()) - static_cast<unsigned>(__rhs.month()));
}
-[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
+template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
operator-(const year_month& __lhs, const months& __rhs) noexcept {
return __lhs + -__rhs;
}
@@ -103,12 +105,12 @@ operator-(const year_month& __lhs, const years& __rhs) noexcept {
return __lhs + -__rhs;
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& year_month::operator+=(const months& __dm) noexcept {
+template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& year_month::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& year_month::operator-=(const months& __dm) noexcept {
+template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& year_month::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
}
>From 4fd4c89b7ce5cd23e0761470a9c60591c6ca1bb7 Mon Sep 17 00:00:00 2001
From: Skyfrei <tarkaklavio at gmail.com>
Date: Thu, 7 May 2026 22:44:21 +0200
Subject: [PATCH 4/4] added test cases to the appropriate place and deleted the
wrong folder
---
libcxx/include/__chrono/year_month.h | 22 ++++++----
libcxx/include/__chrono/year_month_day.h | 40 +++++++++++-------
libcxx/test/std/chrono/arithmetic.pass.cpp | 41 -------------------
.../plus_minus_equal_month.pass.cpp | 33 +++++++++++++++
4 files changed, 72 insertions(+), 64 deletions(-)
delete mode 100644 libcxx/test/std/chrono/arithmetic.pass.cpp
diff --git a/libcxx/include/__chrono/year_month.h b/libcxx/include/__chrono/year_month.h
index 04dc9b595b3e9..222b00b95d41a 100644
--- a/libcxx/include/__chrono/year_month.h
+++ b/libcxx/include/__chrono/year_month.h
@@ -38,9 +38,9 @@ class year_month {
: __y_{__yval}, __m_{__mval} {}
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year year() const noexcept { return __y_; }
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m_; }
- template<class = void>
+ template <class = void>
_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator+=(const months& __dm) noexcept;
- template<class = void>
+ template <class = void>
_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator-=(const months& __dm) noexcept;
_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator+=(const years& __dy) noexcept;
_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator-=(const years& __dy) noexcept;
@@ -66,7 +66,8 @@ operator<=>(const year_month& __lhs, const year_month& __rhs) noexcept {
return __lhs.month() <=> __rhs.month();
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
operator+(const year_month& __lhs, const months& __rhs) noexcept {
int __dmi = static_cast<int>(static_cast<unsigned>(__lhs.month())) - 1 + __rhs.count();
const int __dy = (__dmi >= 0 ? __dmi : __dmi - 11) / 12;
@@ -74,7 +75,8 @@ operator+(const year_month& __lhs, const months& __rhs) noexcept {
return (__lhs.year() + years(__dy)) / month(static_cast<unsigned>(__dmi));
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
operator+(const months& __lhs, const year_month& __rhs) noexcept {
return __rhs + __lhs;
}
@@ -89,13 +91,15 @@ operator+(const years& __lhs, const year_month& __rhs) noexcept {
return __rhs + __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr months
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr months
operator-(const year_month& __lhs, const year_month& __rhs) noexcept {
return (__lhs.year() - __rhs.year()) +
months(static_cast<unsigned>(__lhs.month()) - static_cast<unsigned>(__rhs.month()));
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month
operator-(const year_month& __lhs, const months& __rhs) noexcept {
return __lhs + -__rhs;
}
@@ -105,12 +109,14 @@ operator-(const year_month& __lhs, const years& __rhs) noexcept {
return __lhs + -__rhs;
}
-template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& year_month::operator+=(const months& __dm) noexcept {
+template <class>
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& year_month::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& year_month::operator-=(const months& __dm) noexcept {
+template <class>
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month& year_month::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
}
diff --git a/libcxx/include/__chrono/year_month_day.h b/libcxx/include/__chrono/year_month_day.h
index 3c79cb7d50a5e..be1925fcdd2ff 100644
--- a/libcxx/include/__chrono/year_month_day.h
+++ b/libcxx/include/__chrono/year_month_day.h
@@ -54,9 +54,9 @@ class year_month_day {
_LIBCPP_HIDE_FROM_ABI inline explicit constexpr year_month_day(const local_days& __locd) noexcept
: year_month_day(__from_days(__locd.time_since_epoch())) {}
- template<class = void>
+ template <class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day& operator+=(const months& __dm) noexcept;
- template<class = void>
+ template <class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day& operator-=(const months& __dm) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day& operator+=(const years& __dy) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day& operator-=(const years& __dy) noexcept;
@@ -151,17 +151,20 @@ operator/(const month_day& __lhs, int __rhs) noexcept {
return year(__rhs) / __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
operator+(const year_month_day& __lhs, const months& __rhs) noexcept {
return (__lhs.year() / __lhs.month() + __rhs) / __lhs.day();
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
operator+(const months& __lhs, const year_month_day& __rhs) noexcept {
return __rhs + __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day
operator-(const year_month_day& __lhs, const months& __rhs) noexcept {
return __lhs + -__rhs;
}
@@ -181,11 +184,13 @@ operator-(const year_month_day& __lhs, const years& __rhs) noexcept {
return __lhs + -__rhs;
}
-template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept {
+template <class>
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator-=(const months& __dm) noexcept {
+template <class>
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
}
@@ -206,10 +211,10 @@ class year_month_day_last {
public:
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last(const year& __yval, const month_day_last& __mdlval) noexcept
: __y_{__yval}, __mdl_{__mdlval} {}
-
- template<class = void>
+
+ template <class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator+=(const months& __m) noexcept;
- template<class = void>
+ template <class = void>
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator-=(const months& __m) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator+=(const years& __y) noexcept;
_LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator-=(const years& __y) noexcept;
@@ -285,17 +290,20 @@ operator/(const month_day_last& __lhs, int __rhs) noexcept {
return year{__rhs} / __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
operator+(const year_month_day_last& __lhs, const months& __rhs) noexcept {
return (__lhs.year() / __lhs.month() + __rhs) / last;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
operator+(const months& __lhs, const year_month_day_last& __rhs) noexcept {
return __rhs + __lhs;
}
-template<class = void>[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
+template <class = void>
+[[nodiscard]] _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last
operator-(const year_month_day_last& __lhs, const months& __rhs) noexcept {
return __lhs + (-__rhs);
}
@@ -315,12 +323,14 @@ operator-(const year_month_day_last& __lhs, const years& __rhs) noexcept {
return __lhs + (-__rhs);
}
-template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last&
+template <class>
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last&
year_month_day_last::operator+=(const months& __dm) noexcept {
*this = *this + __dm;
return *this;
}
-template<class>_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last&
+template <class>
+_LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last&
year_month_day_last::operator-=(const months& __dm) noexcept {
*this = *this - __dm;
return *this;
diff --git a/libcxx/test/std/chrono/arithmetic.pass.cpp b/libcxx/test/std/chrono/arithmetic.pass.cpp
deleted file mode 100644
index f1b5d3946fa1c..0000000000000
--- a/libcxx/test/std/chrono/arithmetic.pass.cpp
+++ /dev/null
@@ -1,41 +0,0 @@
-#include <chrono>
-
-using namespace std::chrono;
-
-constexpr bool test_month() {
- using decamonths = duration<int, std::ratio_multiply<std::ratio<10>, months::period>>;
- auto ymd = 2001y/January/1d;
- auto ymd2 = 2001y/January/1d;
- ymd2 += std::chrono::duration_cast<std::chrono::months>(decamonths(1));
- ymd += decamonths(1);
-
-
- if (ymd2.month() != November)
- return false;
-
- return ymd == 2001y/November/1d;
-}
-
-constexpr bool test_year() {
- using decades = duration<int, std::ratio_multiply<std::ratio<10>, years::period>>;
- auto ymd = 2001y/January/1d;
-
- ymd += duration_cast<years>(decades(1));
-
- return ymd == 2011y/January/1d;
-}
-
-constexpr bool doc_ambig_test(){
- using decades = duration<int, std::ratio_multiply<std::ratio<10>, years::period>>;
- auto ymd = 2001y/January/1d;
- ymd += decades(1);
- return true;
-}
-
-int main(int, char**) {
- static_assert(test_month(), "Month arithmetic failed");
- static_assert(test_year(), "Year arithmetic failed");
- static_assert(doc_ambig_test(), "Doc");
-
- return 0;
-}
diff --git a/libcxx/test/std/time/time.cal/time.cal.ym/time.cal.ym.members/plus_minus_equal_month.pass.cpp b/libcxx/test/std/time/time.cal/time.cal.ym/time.cal.ym.members/plus_minus_equal_month.pass.cpp
index a67286b85c04a..e915ed809e4bf 100644
--- a/libcxx/test/std/time/time.cal/time.cal.ym/time.cal.ym.members/plus_minus_equal_month.pass.cpp
+++ b/libcxx/test/std/time/time.cal/time.cal.ym/time.cal.ym.members/plus_minus_equal_month.pass.cpp
@@ -23,7 +23,11 @@
using month = std::chrono::month;
using months = std::chrono::months;
using year = std::chrono::year;
+using years = std::chrono::years;
using year_month = std::chrono::year_month;
+using ymd_t = std::chrono::year_month_day;
+using decades = std::chrono::duration<int, std::ratio_multiply<std::ratio<10>, years::period>>;
+using decamonths = std::chrono::duration<int, std::ratio_multiply<std::ratio<10>, months::period>>;
constexpr bool test() {
for (unsigned i = 0; i <= 10; ++i) {
@@ -49,6 +53,35 @@ constexpr bool test() {
assert((ym == year_month{year{2020}, month{4}}));
}
+ { // Ambiguity test, defaults to year arithmetic
+ for(unsigned int i = 0; i < 10; i++){
+ year y{2011};
+ month m{i};
+ ymd_t ymd (y, m, std::chrono::day{i});
+ year_month ym(y, m);
+
+ ymd += decades(1);
+ assert(ymd.year() == y + years{10});
+ assert(ymd.month() == m);
+
+ ymd += decamonths(1);
+ assert(ymd.month() == m + months{10});
+
+ ymd.operator+=<void>(decamonths(1));
+ assert(ymd.month() == m + months{20});
+
+ ym += decades(1);
+ assert(ym.year() == y + years{10});
+ assert(ym.month() == m);
+
+ ym += decamonths(1);
+ assert(ym.month() == m + months{10});
+
+ ym.operator+=<void>(decamonths(1));
+ assert(ym.month() == m + months{20});
+ }
+ }
+
return true;
}
More information about the libcxx-commits
mailing list