[NFC][libc++] Refactors the time.cal tests. (#73356)

These tests use an old way to test code in constexpr context. This
changes the code to the idomatic libc++ method.

This is a preparation for #73162.

Side changes
- Updated formatting
- Made some helper functions constexpr
- Some naming improvements

Author: mordante

libcxx/test/std/time/time.cal/euclidian.h

@@ -12,27 +12,25 @@
 //  Assumption: minValue <= lhs <= maxValue
 //  Assumption: minValue >= 0
 template <typename T, T minValue, T maxValue>
-T euclidian_addition(T rhs, T lhs)
-{
-    const T modulus = maxValue - minValue + 1;
-    T ret = rhs + lhs;
-    if (ret > maxValue)
-        ret -= modulus;
-    return ret;
+constexpr T euclidian_addition(T rhs, T lhs) {
+  const T modulus = maxValue - minValue + 1;
+  T ret           = rhs + lhs;
+  if (ret > maxValue)
+    ret -= modulus;
+  return ret;
 }
 
 //  Assumption: minValue < maxValue
 //  Assumption: minValue <= rhs <= maxValue
 //  Assumption: minValue <= lhs <= maxValue
 //  Assumption: minValue >= 0
 template <typename T, T minValue, T maxValue>
-T euclidian_subtraction(T lhs, T rhs)
-{
-    const T modulus = maxValue - minValue + 1;
-    T ret = lhs - rhs;
-    if (ret < minValue)
-        ret += modulus;
-    if (ret > maxValue)     // this can happen if T is unsigned
-        ret += modulus;
-    return ret;
+constexpr T euclidian_subtraction(T lhs, T rhs) {
+  const T modulus = maxValue - minValue + 1;
+  T ret           = lhs - rhs;
+  if (ret < minValue)
+    ret += modulus;
+  if (ret > maxValue) // this can happen if T is unsigned
+    ret += modulus;
+  return ret;
 }

libcxx/test/std/time/time.cal/time.cal.day/time.cal.day.members/decrement.pass.cpp

@@ -13,41 +13,33 @@
 //  constexpr day& operator--() noexcept;
 //  constexpr day operator--(int) noexcept;
 
-
 #include <chrono>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 
-template <typename D>
-constexpr bool testConstexpr()
-{
-    D d1{10};
-    if (static_cast<unsigned>(--d1) != 9) return false;
-    if (static_cast<unsigned>(d1--) != 9) return false;
-    if (static_cast<unsigned>(d1)   != 8) return false;
-    return true;
-}
+using day = std::chrono::day;
 
-int main(int, char**)
-{
-    using day = std::chrono::day;
-    ASSERT_NOEXCEPT(--(std::declval<day&>())  );
-    ASSERT_NOEXCEPT(  (std::declval<day&>())--);
+constexpr bool test() {
+  for (unsigned i = 10; i <= 20; ++i) {
+    day d(i);
+    assert(static_cast<unsigned>(--d) == i - 1);
+    assert(static_cast<unsigned>(d--) == i - 1);
+    assert(static_cast<unsigned>(d) == i - 2);
+  }
+  return true;
+}
 
-    ASSERT_SAME_TYPE(day , decltype(  std::declval<day&>()--));
-    ASSERT_SAME_TYPE(day&, decltype(--std::declval<day&>()  ));
+int main(int, char**) {
+  ASSERT_NOEXCEPT(--(std::declval<day&>()));
+  ASSERT_NOEXCEPT((std::declval<day&>())--);
 
-    static_assert(testConstexpr<day>(), "");
+  ASSERT_SAME_TYPE(day, decltype(std::declval<day&>()--));
+  ASSERT_SAME_TYPE(day&, decltype(--std::declval<day&>()));
 
-    for (unsigned i = 10; i <= 20; ++i)
-    {
-        day d(i);
-        assert(static_cast<unsigned>(--d) == i - 1);
-        assert(static_cast<unsigned>(d--) == i - 1);
-        assert(static_cast<unsigned>(d)   == i - 2);
-    }
+  test();
+  static_assert(test());
 
   return 0;
 }

libcxx/test/std/time/time.cal/time.cal.day/time.cal.day.members/increment.pass.cpp

@@ -13,41 +13,34 @@
 //  constexpr day& operator++() noexcept;
 //  constexpr day operator++(int) noexcept;
 
-
 #include <chrono>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 
-template <typename D>
-constexpr bool testConstexpr()
-{
-    D d1{1};
-    if (static_cast<unsigned>(++d1) != 2) return false;
-    if (static_cast<unsigned>(d1++) != 2) return false;
-    if (static_cast<unsigned>(d1)   != 3) return false;
-    return true;
-}
+using day = std::chrono::day;
 
-int main(int, char**)
-{
-    using day = std::chrono::day;
-    ASSERT_NOEXCEPT(++(std::declval<day&>())  );
-    ASSERT_NOEXCEPT(  (std::declval<day&>())++);
+constexpr bool test() {
+  for (unsigned i = 10; i <= 20; ++i) {
+    day d(i);
+    assert(static_cast<unsigned>(++d) == i + 1);
+    assert(static_cast<unsigned>(d++) == i + 1);
+    assert(static_cast<unsigned>(d) == i + 2);
+  }
+
+  return true;
+}
 
-    ASSERT_SAME_TYPE(day , decltype(  std::declval<day&>()++));
-    ASSERT_SAME_TYPE(day&, decltype(++std::declval<day&>()  ));
+int main(int, char**) {
+  ASSERT_NOEXCEPT(++(std::declval<day&>()));
+  ASSERT_NOEXCEPT((std::declval<day&>())++);
 
-    static_assert(testConstexpr<day>(), "");
+  ASSERT_SAME_TYPE(day, decltype(std::declval<day&>()++));
+  ASSERT_SAME_TYPE(day&, decltype(++std::declval<day&>()));
 
-    for (unsigned i = 10; i <= 20; ++i)
-    {
-        day d(i);
-        assert(static_cast<unsigned>(++d) == i + 1);
-        assert(static_cast<unsigned>(d++) == i + 1);
-        assert(static_cast<unsigned>(d)   == i + 2);
-    }
+  test();
+  static_assert(test());
 
   return 0;
 }

libcxx/test/std/time/time.cal/time.cal.day/time.cal.day.members/plus_minus_equal.pass.cpp

@@ -19,40 +19,30 @@
 
 #include "test_macros.h"
 
-template <typename D, typename Ds>
-constexpr bool testConstexpr()
-{
-    D d1{1};
-    if (static_cast<unsigned>(d1 += Ds{ 1}) !=  2) return false;
-    if (static_cast<unsigned>(d1 += Ds{ 2}) !=  4) return false;
-    if (static_cast<unsigned>(d1 += Ds{22}) != 26) return false;
-    if (static_cast<unsigned>(d1 -= Ds{ 1}) != 25) return false;
-    if (static_cast<unsigned>(d1 -= Ds{ 2}) != 23) return false;
-    if (static_cast<unsigned>(d1 -= Ds{22}) !=  1) return false;
-    return true;
+using day  = std::chrono::day;
+using days = std::chrono::days;
+
+constexpr bool test() {
+  for (unsigned i = 0; i <= 10; ++i) {
+    day d(i);
+    assert(static_cast<unsigned>(d += days{22}) == i + 22);
+    assert(static_cast<unsigned>(d) == i + 22);
+    assert(static_cast<unsigned>(d -= days{12}) == i + 10);
+    assert(static_cast<unsigned>(d) == i + 10);
+  }
+
+  return true;
 }
 
-int main(int, char**)
-{
-    using day  = std::chrono::day;
-    using days = std::chrono::days;
+int main(int, char**) {
+  ASSERT_NOEXCEPT(std::declval<day&>() += std::declval<days>());
+  ASSERT_NOEXCEPT(std::declval<day&>() -= std::declval<days>());
 
-    ASSERT_NOEXCEPT(std::declval<day&>() += std::declval<days>());
-    ASSERT_NOEXCEPT(std::declval<day&>() -= std::declval<days>());
+  ASSERT_SAME_TYPE(day&, decltype(std::declval<day&>() += std::declval<days>()));
+  ASSERT_SAME_TYPE(day&, decltype(std::declval<day&>() -= std::declval<days>()));
 
-    ASSERT_SAME_TYPE(day&, decltype(std::declval<day&>() += std::declval<days>()));
-    ASSERT_SAME_TYPE(day&, decltype(std::declval<day&>() -= std::declval<days>()));
-
-    static_assert(testConstexpr<day, days>(), "");
-
-    for (unsigned i = 0; i <= 10; ++i)
-    {
-        day d(i);
-        assert(static_cast<unsigned>(d += days{22}) == i + 22);
-        assert(static_cast<unsigned>(d)             == i + 22);
-        assert(static_cast<unsigned>(d -= days{12}) == i + 10);
-        assert(static_cast<unsigned>(d)             == i + 10);
-    }
+  test();
+  static_assert(test());
 
   return 0;
 }

libcxx/test/std/time/time.cal/time.cal.day/time.cal.day.nonmembers/minus.pass.cpp

@@ -16,44 +16,36 @@
 // constexpr days operator-(const day& x, const day& y) noexcept;
 //   Returns: days{int(unsigned{x}) - int(unsigned{y}).
 
-
 #include <chrono>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 
-template <typename D, typename Ds>
-constexpr bool testConstexpr()
-{
-    D d{23};
-    Ds offset{6};
-    if (d - offset != D{17}) return false;
-    if (d - D{17} != offset) return false;
-    return true;
-}
+using day  = std::chrono::day;
+using days = std::chrono::days;
 
-int main(int, char**)
-{
-    using day  = std::chrono::day;
-    using days = std::chrono::days;
+constexpr bool test() {
+  day dy{12};
+  for (unsigned i = 0; i <= 10; ++i) {
+    day d1   = dy - days{i};
+    days off = dy - day{i};
+    assert(static_cast<unsigned>(d1) == 12 - i);
+    assert(off.count() == static_cast<int>(12 - i)); // days is signed
+  }
 
-    ASSERT_NOEXCEPT(std::declval<day>() - std::declval<days>());
-    ASSERT_NOEXCEPT(std::declval<day>() - std::declval<day>());
+  return true;
+}
 
-    ASSERT_SAME_TYPE(day,  decltype(std::declval<day>() - std::declval<days>()));
-    ASSERT_SAME_TYPE(days, decltype(std::declval<day>() - std::declval<day>()));
+int main(int, char**) {
+  ASSERT_NOEXCEPT(std::declval<day>() - std::declval<days>());
+  ASSERT_NOEXCEPT(std::declval<day>() - std::declval<day>());
 
-    static_assert(testConstexpr<day, days>(), "");
+  ASSERT_SAME_TYPE(day, decltype(std::declval<day>() - std::declval<days>()));
+  ASSERT_SAME_TYPE(days, decltype(std::declval<day>() - std::declval<day>()));
 
-    day dy{12};
-    for (unsigned i = 0; i <= 10; ++i)
-    {
-        day d1   = dy - days{i};
-        days off = dy - day {i};
-        assert(static_cast<unsigned>(d1) == 12 - i);
-        assert(off.count() == static_cast<int>(12 - i)); // days is signed
-    }
+  test();
+  static_assert(test());
 
   return 0;
 }

libcxx/test/std/time/time.cal/time.cal.day/time.cal.day.nonmembers/plus.pass.cpp

@@ -16,45 +16,37 @@
 // constexpr day operator+(const days& x, const day& y) noexcept;
 //   Returns: y + x.
 
-
 #include <chrono>
 #include <type_traits>
 #include <cassert>
 
 #include "test_macros.h"
 
-template <typename D, typename Ds>
-constexpr bool testConstexpr()
-{
-    D d{1};
-    Ds offset{23};
-    if (d + offset != D{24}) return false;
-    if (offset + d != D{24}) return false;
-    return true;
-}
+using day  = std::chrono::day;
+using days = std::chrono::days;
 
-int main(int, char**)
-{
-    using day  = std::chrono::day;
-    using days = std::chrono::days;
+constexpr bool test() {
+  day dy{12};
+  for (unsigned i = 0; i <= 10; ++i) {
+    day d1 = dy + days{i};
+    day d2 = days{i} + dy;
+    assert(d1 == d2);
+    assert(static_cast<unsigned>(d1) == i + 12);
+    assert(static_cast<unsigned>(d2) == i + 12);
+  }
 
-    ASSERT_NOEXCEPT(std::declval<day>() + std::declval<days>());
-    ASSERT_NOEXCEPT(std::declval<days>() + std::declval<day>());
+  return true;
+}
 
-    ASSERT_SAME_TYPE(day, decltype(std::declval<day>() + std::declval<days>()));
-    ASSERT_SAME_TYPE(day, decltype(std::declval<days>() + std::declval<day>()));
+int main(int, char**) {
+  ASSERT_NOEXCEPT(std::declval<day>() + std::declval<days>());
+  ASSERT_NOEXCEPT(std::declval<days>() + std::declval<day>());
 
-    static_assert(testConstexpr<day, days>(), "");
+  ASSERT_SAME_TYPE(day, decltype(std::declval<day>() + std::declval<days>()));
+  ASSERT_SAME_TYPE(day, decltype(std::declval<days>() + std::declval<day>()));
 
-    day dy{12};
-    for (unsigned i = 0; i <= 10; ++i)
-    {
-        day d1 = dy + days{i};
-        day d2 = days{i} + dy;
-        assert(d1 == d2);
-        assert(static_cast<unsigned>(d1) == i + 12);
-        assert(static_cast<unsigned>(d2) == i + 12);
-    }
+  test();
+  static_assert(test());
 
   return 0;
 }