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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
// <chrono>
// class month;
// constexpr month operator-(const month& x, const months& y) noexcept;
// Returns: x + -y.
//
// constexpr months operator-(const month& x, const month& y) noexcept;
// Returns: If x.ok() == true and y.ok() == true, returns a value m in the range
// [months{0}, months{11}] satisfying y + m == x.
// Otherwise the value returned is unspecified.
// [Example: January - February == months{11}. —end example]
extern "C" int printf(const char *, ...);
#include <chrono>
#include <type_traits>
#include <cassert>
#include "test_macros.h"
template <typename M, typename Ms>
constexpr bool testConstexpr()
{
{
M m{5};
Ms offset{3};
if (m - offset != M{2}) return false;
if (m - M{2} != offset) return false;
}
// Check the example
if (M{1} - M{2} != Ms{11}) return false;
return true;
}
#include <iostream>
int main()
{
using month = std::chrono::month;
using months = std::chrono::months;
ASSERT_NOEXCEPT(std::declval<month>() - std::declval<months>());
ASSERT_NOEXCEPT(std::declval<month>() - std::declval<month>());
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>(), "");
month m{6};
for (unsigned i = 1; i <= 12; ++i)
{
month m1 = m - months{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));
}
}
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