// { dg-do compile { target c++20 } }
// Copyright (C) 2020-2025 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// .
// Class template day [time.cal.month]
#include
#include
constexpr void
constexpr_month()
{
using namespace std::chrono;
month dm{};
++(++dm);
dm++;
--(--dm);
dm--;
dm += months{3};
dm -= months{3};
// Test for UB (overflow).
{
using rep = months::rep;
using std::numeric_limits;
auto constexpr months_min = months{numeric_limits::min()};
auto constexpr month_000_plus_months_min = month{ 0 } + months_min;
auto constexpr month_255_plus_months_min = month{255} + months_min;
auto constexpr month_000_minus_months_min = month{ 0 } - months_min;
auto constexpr month_255_minus_months_min = month{255} - months_min;
auto constexpr months_max = months{numeric_limits::max()};
auto constexpr month_000_plus_months_max = month{ 0 } + months_max;
auto constexpr month_255_plus_months_max = month{255} + months_max;
auto constexpr month_000_minus_months_max = month{ 0 } - months_max;
auto constexpr month_255_minus_months_max = month{255} - months_max;
}
static_assert(February + months{11} == January);
static_assert(January + months{1200} == January);
static_assert(January + months{1201} == February);
static_assert(months{-1200} + January == January);
static_assert(months{-1201} + January == December);
static_assert(January - months{1200} == January);
static_assert(January - months{-1200} == January);
static_assert(January - months{1201} == December);
static_assert(January - February == months{11});
static_assert(February - January == months{1});
static_assert(June - June == months{});
static_assert(++month{4} == month{5});
static_assert(month{4}++ == month{4});
static_assert(--month{4} == month{3});
static_assert(month{4}-- == month{4});
static_assert((month{4} += months{3}) == month{7});
static_assert((month{4} -= months{3}) == month{1});
static_assert(!month{}.ok());
static_assert(month{1}.ok());
static_assert(month{12}.ok());
static_assert(!month{13}.ok());
static_assert(unsigned{month{7}} == 7);
static_assert(!(month{0} == month{1}));
static_assert( (month{0} != month{2}));
static_assert( (month{0} < month{3}));
static_assert(!(month{0} > month{4}));
static_assert( (month{0} <= month{5}));
static_assert(!(month{0} >= month{6}));
static_assert(month{0} <=> month{1} == std::strong_ordering::less);
static_assert(month{3} <=> month{3} == std::strong_ordering::equal);
static_assert(month{5} <=> month{2} == std::strong_ordering::greater);
}