[libc++] [LWG3221] Add tests for wrapping operator+(year_month, months).

[curdeius]

Summary

The behaviour didn't change since commit 5b08c1742a536f54bd5e270b00ff851cbc7314ef (Recommit <chrono> changes with a couple xtra tests marked to fail on apple's clang.)

• http://wg21.link/lwg3221

[Mordante]

A few minor nits, but otherwise LGTM.

libcxx/test/std/utilities/time/time.cal/time.cal.ym/time.cal.ym.nonmembers/plus.pass.cpp

31–32

Since you're cleaning up this code. would it make sense to change these ifs by asserts?

106

Since the test is C++20, can you remove the empty string?

132

Since the test is C++20, can you remove the empty string?

[curdeius]

• Use assert. Get rid of empty message in static_assert.

[curdeius]

libcxx/test/std/utilities/time/time.cal/time.cal.ym/time.cal.ym.nonmembers/plus.pass.cpp

38–52

Actually I should get rid of these two, since I test the whole test() now in constexpr context. WDYT?

[ldionne]

libcxx/docs/Cxx2aStatusIssuesStatus.csv

171

You checked the blame to figure out what version we shipped that in?

libcxx/test/std/utilities/time/time.cal/time.cal.ym/time.cal.ym.nonmembers/plus.pass.cpp

38–52

Agreed.

[Mordante]

libcxx/test/std/utilities/time/time.cal/time.cal.ym/time.cal.ym.nonmembers/plus.pass.cpp

38–52

Good point. I agree.

[curdeius]

• Remove old constexpr tests.

[curdeius]

libcxx/docs/Cxx2aStatusIssuesStatus.csv

171

Yes, that's what I did. I updated the summary to mention the concerned commit.

[ldionne]

Thanks!

libcxx/docs/Cxx2aStatusIssuesStatus.csv

 "`3231 <https://wg21.link/LWG3231>`__","``year_month_day_last::day``\  specification does not cover ``!ok()``\  values","Belfast","|Nothing To Do|",""
 "`3225 <https://wg21.link/LWG3225>`__","``zoned_time``\  converting constructor shall not be ``noexcept``\ ","Belfast","",""
 "`3190 <https://wg21.link/LWG3190>`__","``std::allocator::allocate``\  sometimes returns too little storage","Belfast","",""
 "`3218 <https://wg21.link/LWG3218>`__","Modifier for ``%d``\  parse flag does not match POSIX and ``format``\  specification","Belfast","",""
 "`3224 <https://wg21.link/LWG3224>`__","``zoned_time``\  constructor from ``TimeZonePtr``\  does not specify initialization of ``tp_``\ ","Belfast","",""
 "`3230 <https://wg21.link/LWG3230>`__","Format specifier ``%y/%Y``\  is missing locale alternative versions","Belfast","",""
 "`3232 <https://wg21.link/LWG3232>`__","Inconsistency in ``zoned_time``\  deduction guides","Belfast","",""
 "`3222 <https://wg21.link/LWG3222>`__","P0574R1 introduced preconditions on non-existent parameters","Belfast","",""
-"`3221 <https://wg21.link/LWG3221>`__","Result of ``year_month``\  arithmetic with ``months``\  is ambiguous","Belfast","",""
+"`3221 <https://wg21.link/LWG3221>`__","Result of ``year_month``\  arithmetic with ``months``\  is ambiguous","Belfast","|Complete|","8.0"
 "`3235 <https://wg21.link/LWG3235>`__","``parse``\  manipulator without abbreviation is not callable","Belfast","",""
 "`3246 <https://wg21.link/LWG3246>`__","What are the constraints on the template parameter of ``basic_format_arg``\ ?","Belfast","",""
 "`3253 <https://wg21.link/LWG3253>`__","``basic_syncbuf::basic_syncbuf()``\  should not be explicit","Belfast","",""
 "`3245 <https://wg21.link/LWG3245>`__","Unnecessary restriction on ``'%p'``\  parse specifier","Belfast","",""
 "`3244 <https://wg21.link/LWG3244>`__","Constraints for ``Source``\  in |sect|\ [fs.path.req] insufficiently constrainty","Belfast","",""
 "`3241 <https://wg21.link/LWG3241>`__","``chrono-spec``\  grammar ambiguity in |sect|\ [time.format]","Belfast","",""
 "`3257 <https://wg21.link/LWG3257>`__","Missing feature testing macro update from P0858","Belfast","",""
 "`3256 <https://wg21.link/LWG3256>`__","Feature testing macro for ``constexpr``\  algorithms","Belfast","",""

libcxx/test/std/utilities/time/time.cal/time.cal.ym/time.cal.ym.nonmembers/plus.pass.cpp

 
 // constexpr year_month operator+(const year_month& ym, const years& dy) noexcept;
 // Returns: (ym.year() + dy) / ym.month().
 //
 // constexpr year_month operator+(const years& dy, const year_month& ym) noexcept;
 // Returns: ym + dy.
 //
 // constexpr year_month operator+(const year_month& ym, const months& dm) noexcept;
-// Returns: A year_month value z such that z - ym == dm.
+// Returns: A year_month value z such that z.ok() && z - ym == dm is true.
 // Complexity: O(1) with respect to the value of dm.
 //
 // constexpr year_month operator+(const months& dm, const year_month& ym) noexcept;
 // Returns: ym + dm.
 
-
-
 #include <chrono>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 
-constexpr bool testConstexprYears(std::chrono::year_month ym)
-{
-    std::chrono::years offset{23};
-    if (static_cast<int>((ym         ).year()) !=  1) return false;
-    if (static_cast<int>((ym + offset).year()) != 24) return false;
-    if (static_cast<int>((offset + ym).year()) != 24) return false;
-    return true;
-}
-
-
-constexpr bool testConstexprMonths(std::chrono::year_month ym)
-{
-    std::chrono::months offset{6};
-    if (static_cast<unsigned>((ym         ).month()) !=  1) return false;
-    if (static_cast<unsigned>((ym + offset).month()) !=  7) return false;
-    if (static_cast<unsigned>((offset + ym).month()) !=  7) return false;
-    return true;
-}
-
-
-int main(int, char**)
-{
-    using year       = std::chrono::year;
-    using years      = std::chrono::years;
-    using month      = std::chrono::month;
-    using months     = std::chrono::months;
-    using year_month = std::chrono::year_month;
+using year = std::chrono::year;
+using years = std::chrono::years;
+using month = std::chrono::month;
+using months = std::chrono::months;
 
-    {   // year_month + years
-    ASSERT_NOEXCEPT(std::declval<year_month>() + std::declval<years>());
-    ASSERT_NOEXCEPT(std::declval<years>() + std::declval<year_month>());
+// year_month + years
+constexpr bool test_ym_plus_y() {
 
-    ASSERT_SAME_TYPE(year_month, decltype(std::declval<year_month>() + std::declval<years>()));
-    ASSERT_SAME_TYPE(year_month, decltype(std::declval<years>() + std::declval<year_month>()));
-
-    static_assert(testConstexprYears (year_month{year{1}, month{1}}), "");
+  ASSERT_SAME_TYPE(
+      year_month, decltype(std::declval<year_month>() + std::declval<years>()));
+  ASSERT_SAME_TYPE(
+      year_month, decltype(std::declval<years>() + std::declval<year_month>()));
 
-    year_month ym{year{1234}, std::chrono::January};
-    for (int i = 0; i <= 10; ++i)
-    {
-        year_month ym1 = ym + years{i};
-        year_month ym2 = years{i} + ym;
-        assert(static_cast<int>(ym1.year()) == i + 1234);
-        assert(static_cast<int>(ym2.year()) == i + 1234);
-        assert(ym1.month() == std::chrono::January);
-        assert(ym2.month() == std::chrono::January);
-        assert(ym1 == ym2);
-    }
-    }
+  for (int i = 0; i <= 10; ++i) {
+
+  return true;
 
-    {   // year_month + months
-    ASSERT_NOEXCEPT(std::declval<year_month>() + std::declval<months>());
-    ASSERT_NOEXCEPT(std::declval<months>() + std::declval<year_month>());
+// year_month + months
+constexpr bool test_ym_plus_m() {
 
-    ASSERT_SAME_TYPE(year_month, decltype(std::declval<year_month>() + std::declval<months>()));
-    ASSERT_SAME_TYPE(year_month, decltype(std::declval<months>() + std::declval<year_month>()));
-
-    static_assert(testConstexprMonths(year_month{year{1}, month{1}}), "");
+  ASSERT_SAME_TYPE(year_month, decltype(std::declval<year_month>() +
+                                        std::declval<months>()));
+  ASSERT_SAME_TYPE(year_month, decltype(std::declval<months>() +
+                                        std::declval<year_month>()));
 
-    year_month ym{year{1234}, std::chrono::January};
-    for (int i = 0; i <= 10; ++i)  // TODO test wrap-around
-    {
-        year_month ym1 = ym + months{i};
-        year_month ym2 = months{i} + ym;
-        assert(static_cast<int>(ym1.year()) == 1234);
-        assert(static_cast<int>(ym2.year()) == 1234);
-        assert(ym1.month() == month(1 + i));
-        assert(ym2.month() == month(1 + i));
-        assert(ym1 == ym2);
-    }
-    }
+  for (int i = 0; i <= 11; ++i) {
+
+  for (int i = 12; i < 23; ++i) {
+    year_month ym1 = ym + months{i};
+    year_month ym2 = months{i} + ym;
+    assert(static_cast<int>(ym1.year()) == 1235);
+    assert(static_cast<int>(ym2.year()) == 1235);
+    assert(ym1.month() == month(1 + i % 12));
+    assert(ym2.month() == month(1 + i % 12));
+    assert(ym1 == ym2);
+  }
+
+  return true;
+}
+
+constexpr bool test() {
+  test_ym_plus_y();
+  test_ym_plus_m();
+  return true;
 
+int main(int, char**) {
+  test();
+  static_assert(test());
+
   return 0;
 }