libstdc++-v3/testsuite/std/time/weekday/1.cc

   1 // { dg-do compile { target c++20 } }
   2
   3 // Copyright (C) 2020-2024 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 // Class template day [time.cal.weekday]
  21
  22 #include <chrono>
  23 #include <limits>
  24
  25 constexpr void
  26 constexpr_weekday()
  27 {
  28   using namespace std::chrono;
  29
  30   weekday dwd{};
  31   ++dwd;
  32   dwd++;
  33   --dwd;
  34   dwd--;
  35   dwd += days{3};
  36   dwd -= days{3};
  37
  38   static_assert(weekday{3}[2].weekday() == weekday{3});
  39   static_assert(weekday{3}[last].weekday() == weekday{3});
  40
  41   // Test for UB (overflow).
  42   {
  43     using rep = days::rep;
  44     using std::numeric_limits;
  45     constexpr weekday max{sys_days{days{numeric_limits<rep>::max()}}};
  46     constexpr weekday min{sys_days{days{numeric_limits<rep>::min()}}};
  47   }
  48
  49   static_assert(weekday{sys_days{1900y/January/1}} == Monday);
  50   static_assert(weekday{sys_days{1970y/January/1}} == Thursday);
  51   static_assert(weekday{sys_days{2020y/August/21}} == Friday);
  52
  53   static_assert(weekday{local_days{1900y/January/1}} == Monday);
  54   static_assert(weekday{local_days{1970y/January/1}} == Thursday);
  55   static_assert(weekday{local_days{2020y/August/21}} == Friday);
  56
  57   static_assert(++weekday{3} == weekday{4});
  58   static_assert(weekday{3}++ == weekday{3});
  59   static_assert(--weekday{3} == weekday{2});
  60   static_assert(weekday{3}-- == weekday{3});
  61   static_assert((weekday{3} += days{3}) == weekday{6});
  62   static_assert((weekday{3} -= days{3}) == weekday{0});
  63
  64   static_assert(Monday + days{7000} == Monday);
  65   static_assert(Monday + days{-7000} == Monday);
  66   static_assert(days{7001} + Monday == Tuesday);
  67   static_assert(days{-7001} + Monday == Sunday);
  68   static_assert(Monday - days{7000} == Monday);
  69   static_assert(Monday - days{-7000} == Monday);
  70   static_assert(Monday - days{7001} == Sunday);
  71
  72   static_assert([] {
  73     constexpr unsigned diff_tbl[7][7]
  74       = { { 0, 6, 5, 4, 3, 2, 1},
  75           { 1, 0, 6, 5, 4, 3, 2},
  76           { 2, 1, 0, 6, 5, 4, 3},
  77           { 3, 2, 1, 0, 6, 5, 4},
  78           { 4, 3, 2, 1, 0, 6, 5},
  79           { 5, 4, 3, 2, 1, 0, 6},
  80           { 6, 5, 4, 3, 2, 1, 0} };
  81     for (unsigned x = 0; x < 7; x++)
  82       for (unsigned y = 0; y < 7; y++)
  83         {
  84           if (weekday{x} - weekday{y} != days{diff_tbl[x][y]})
  85             return false;
  86           if (weekday{x} - days{diff_tbl[x][y]} != weekday{y})
  87             return false;
  88           if (weekday{x} != weekday{y} + days{diff_tbl[x][y]})
  89             return false;
  90           if (weekday{x} != days{diff_tbl[x][y]} + weekday{y})
  91             return false;
  92         }
  93     return true;
  94   }());
  95
  96   static_assert(Sunday.c_encoding() == 0);
  97   static_assert(Sunday.iso_encoding() == 7);
  98   static_assert(Monday.c_encoding() == 1);
  99   static_assert(Monday.iso_encoding() == 1);
 100
 101   static_assert(!weekday{127}.ok());
 102   static_assert(weekday{0}.ok());
 103   static_assert(weekday{6}.ok());
 104   static_assert(weekday{7}.ok()); // Ctor wraps 7 to 0.
 105   static_assert(!weekday{8}.ok());
 106
 107   static_assert(weekday{7} == weekday{0});
 108   static_assert(!(weekday{0} == weekday{1}));
 109   static_assert( (weekday{0} != weekday{2}));
 110 }