[libcxx] chrono::month_weekday should not be default constructible

It was not in P0355R7, nor has it ever been so in a working draft.

Drive-by:
* tests should test something: fix loop bounds so initial value is not >= final value
* calender type streaming tests are useless - let's remove them
* don't declare printf, especially if you don't intend to use it

Differential Revision: https://reviews.llvm.org/D117638

libcxx/docs/ReleaseNotes.rst

@@ -108,6 +108,9 @@ API Changes
   as either ``for (auto&& c : path)`` or ``for (const auto& c : path)``.
   ``std::reverse_iterator<path::iterator>`` is no longer rejected.
 
+- Removed the nonstandard default constructor from ``std::chrono::month_weekday``.
+  You must now explicitly initialize with a ``chrono::month`` and
+  ``chrono::weekday_indexed`` instead of "meh, whenever".
 
 ABI Changes
 -----------

libcxx/include/__chrono/calendar.h

@@ -540,7 +540,6 @@ class month_weekday {
     chrono::month __m;
     chrono::weekday_indexed __wdi;
 public:
-    month_weekday() = default;
     constexpr month_weekday(const chrono::month& __mval, const chrono::weekday_indexed& __wdival) noexcept
         : __m{__mval}, __wdi{__wdival} {}
     inline constexpr chrono::month                     month() const noexcept { return __m; }

libcxx/test/std/utilities/time/time.cal/time.cal.day/time.cal.day.nonmembers/comparisons.pass.cpp

@@ -33,7 +33,7 @@ int main(int, char**)
     static_assert(testComparisons6Values<day>(0U, 0U), "");
     static_assert(testComparisons6Values<day>(0U, 1U), "");
 
-//  Some 'ok' values as well
+    //  Some 'ok' values as well
     static_assert(testComparisons6Values<day>( 5U,  5U), "");
     static_assert(testComparisons6Values<day>( 5U, 10U), "");
 

libcxx/test/std/utilities/time/time.cal/time.cal.md/time.cal.md.members/ok.pass.cpp

@@ -48,7 +48,7 @@ int main(int, char**)
         assert(!(month_day{month{i}, day{32}}.ok()));
     }
 
-//  If the month is not ok, all the days are bad
+    //  If the month is not ok, all the days are bad
     for (unsigned i = 1; i <= 35; ++i)
         assert(!(month_day{month{13}, day{i}}.ok()));
 

libcxx/test/std/utilities/time/time.cal/time.cal.md/time.cal.md.nonmembers/comparisons.pass.cpp

@@ -50,15 +50,15 @@ int main(int, char**)
         month_day{std::chrono::February, day{1}},
         false, true), "");
 
-//  same day, different months
+    //  same day, different months
     for (unsigned i = 1; i < 12; ++i)
         for (unsigned j = 1; j < 12; ++j)
             assert((testComparisons6(
                 month_day{month{i}, day{1}},
                 month_day{month{j}, day{1}},
                 i == j, i < j )));
 
-//  same month, different days
+    //  same month, different days
     for (unsigned i = 1; i < 31; ++i)
         for (unsigned j = 1; j < 31; ++j)
             assert((testComparisons6(

libcxx/test/std/utilities/time/time.cal/time.cal.mdlast/comparisons.pass.cpp

@@ -35,10 +35,10 @@ int main(int, char**)
     static_assert( testComparisons6Values<month_day_last>(month{1}, month{1}), "");
     static_assert( testComparisons6Values<month_day_last>(month{1}, month{2}), "");
 
-//  same day, different months
-    for (unsigned i = 1; i < 12; ++i)
-        for (unsigned j = 1; j < 12; ++j)
-            assert((testComparisons6Values<month_day_last>(month{i}, month{j})));
+    // same day, different months
+    for (unsigned i = 1; i <= 12; ++i)
+        for (unsigned j = 1; j <= 12; ++j)
+            assert(testComparisons6Values<month_day_last>(month{i}, month{j}));
 
-  return 0;
+    return 0;
 }

libcxx/test/std/utilities/time/time.cal/time.cal.mdlast/ok.pass.cpp

@@ -36,7 +36,7 @@ int main(int, char**)
         assert( mdl.ok());
     }
 
-//  If the month is not ok, all the days are bad
+    //  If the month is not ok, all the days are bad
     for (unsigned i = 13; i <= 50; ++i)
     {
         month_day_last mdl{month{i}};

libcxx/test/std/utilities/time/time.cal/time.cal.month/time.cal.month.nonmembers/comparisons.pass.cpp

@@ -36,12 +36,12 @@ int main(int, char**)
     static_assert(testComparisons6Values<month>(0U ,0U), "");
     static_assert(testComparisons6Values<month>(0U, 1U), "");
 
-//  Some 'ok' values as well
+    //  Some 'ok' values as well
     static_assert(testComparisons6Values<month>( 5U,  5U), "");
     static_assert(testComparisons6Values<month>( 5U, 10U), "");
 
-    for (unsigned i = 1; i < 10; ++i)
-        for (unsigned j = 10; j < 10; ++j)
+    for (unsigned i = 1; i <= 12; ++i)
+        for (unsigned j = 1; j <= 12; ++j)
             assert(testComparisons6Values<month>(i, j));
 
   return 0;

libcxx/test/std/utilities/time/time.cal/time.cal.month/time.cal.month.nonmembers/minus.pass.cpp

@@ -31,12 +31,13 @@ constexpr bool testConstexpr()
     {
     M m{5};
     Ms offset{3};
-    if (m - offset != M{2}) return false;
-    if (m - M{2} != offset) return false;
+    assert(m - offset == M{2});
+    assert(m - M{2} == offset);
     }
 
-//  Check the example
-    if (M{1} - M{2} != Ms{11}) return false;
+    //  Check the example
+    assert(M{1} - M{2} == Ms{11});
+
     return true;
 }
 
@@ -51,18 +52,18 @@ int main(int, char**)
     ASSERT_SAME_TYPE(month , decltype(std::declval<month>() - std::declval<months>()));
     ASSERT_SAME_TYPE(months, decltype(std::declval<month>() - std::declval<month> ()));
 
-static_assert(testConstexpr<month, months>(), "");
+    static_assert(testConstexpr<month, months>(), "");
 
     month m{6};
     for (unsigned i = 1; i <= 12; ++i)
     {
         month m1   = m - months{i};
-//      months off = m - month {i};
+        // months off = m - month {i};
         int exp = 6 - i;
         if (exp < 1)
             exp += 12;
         assert(static_cast<unsigned>(m1) == static_cast<unsigned>(exp));
-//          assert(off.count()               == static_cast<unsigned>(exp));
+        // assert(off.count()            == static_cast<unsigned>(exp));
     }
 
   return 0;

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

@@ -36,10 +36,10 @@ constexpr bool testConstexpr()
 {
     M m{1};
     Ms offset{4};
-    if (m + offset != M{5}) return false;
-    if (offset + m != M{5}) return false;
-//  Check the example
-    if (M{2} + Ms{11} != M{1}) return false;
+    assert(m + offset == M{5});
+    assert(offset + m == M{5});
+    //  Check the example
+    assert(M{2} + Ms{11} == M{1});
     return true;
 }
 
@@ -69,5 +69,5 @@ int main(int, char**)
         assert(static_cast<unsigned>(m2) == exp);
     }
 
-  return 0;
+    return 0;
 }

libcxx/test/std/utilities/time/time.cal/time.cal.mwd/time.cal.mwd.members/month.pass.cpp

@@ -31,8 +31,6 @@ int main(int, char**)
     ASSERT_NOEXCEPT(                 std::declval<const month_weekday>().month());
     ASSERT_SAME_TYPE(month, decltype(std::declval<const month_weekday>().month()));
 
-    static_assert( month_weekday{}.month() == month{}, "");
-
     for (unsigned i = 1; i <= 50; ++i)
     {
         month_weekday md(month{i}, weekday_indexed{Sunday, 1});

libcxx/test/std/utilities/time/time.cal/time.cal.mwd/time.cal.mwd.members/ok.pass.cpp

@@ -44,9 +44,9 @@ int main(int, char**)
             assert(mwd.ok() == (j >= 1 && j <= 5));
         }
 
-//  If the month is not ok, all the weekday_indexed are bad
+    //  If the month is not ok, all the weekday_indexed are bad
     for (unsigned i = 1; i <= 10; ++i)
         assert(!(month_weekday{month{13}, weekday_indexed{Sunday, i}}.ok()));
 
-  return 0;
+    return 0;
 }