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

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 // UNSUPPORTED: c++03, c++11, c++14, c++17
   9
  10 // <chrono>
  11 // class month;
  12
  13 // constexpr month& operator+=(const month& d) noexcept;
  14 // constexpr month& operator-=(const month& d) noexcept;
  15
  16 #include <chrono>
  17 #include <type_traits>
  18 #include <cassert>
  19
  20 #include "test_macros.h"
  21
  22 constexpr bool test() {
  23   using month  = std::chrono::month;
  24   using months = std::chrono::months;
  25
  26   for (unsigned i = 1; i <= 10; ++i) {
  27     month m(i);
  28     int exp = i + 10;
  29     while (exp > 12)
  30       exp -= 12;
  31     assert(static_cast<unsigned>(m += months{10}) == static_cast<unsigned>(exp));
  32     assert(static_cast<unsigned>(m) == static_cast<unsigned>(exp));
  33     assert(m.ok());
  34   }
  35
  36   for (unsigned i = 1; i <= 10; ++i) {
  37     month m(i);
  38     int exp = i - 9;
  39     while (exp < 1)
  40       exp += 12;
  41     assert(static_cast<unsigned>(m -= months{9}) == static_cast<unsigned>(exp));
  42     assert(static_cast<unsigned>(m) == static_cast<unsigned>(exp));
  43     assert(m.ok());
  44   }
  45   return true;
  46 }
  47
  48 int main(int, char**) {
  49   using month  = std::chrono::month;
  50   using months = std::chrono::months;
  51
  52   ASSERT_NOEXCEPT(std::declval<month&>() += std::declval<months&>());
  53   ASSERT_NOEXCEPT(std::declval<month&>() -= std::declval<months&>());
  54   ASSERT_SAME_TYPE(month&, decltype(std::declval<month&>() += std::declval<months&>()));
  55   ASSERT_SAME_TYPE(month&, decltype(std::declval<month&>() -= std::declval<months&>()));
  56
  57   test();
  58   static_assert(test());
  59
  60   return 0;
  61 }