1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
10
11 // <chrono>
12 // class year;
13
14 // constexpr year operator-(const year& x, const years& y) noexcept;
15 // Returns: x + -y.
16 //
17 // constexpr years operator-(const year& x, const year& y) noexcept;
18 // Returns: If x.ok() == true and y.ok() == true, returns a value m in the range
19 // [years{0}, years{11}] satisfying y + m == x.
20 // Otherwise the value returned is unspecified.
21 // [Example: January - February == years{11}. —end example]
22
23 extern "C" int printf(const char *, ...);
24
25 #include <chrono>
26 #include <type_traits>
27 #include <cassert>
28
29 #include "test_macros.h"
30
31 template <typename Y, typename Ys>
testConstexpr()32 constexpr bool testConstexpr()
33 {
34 Y y{2313};
35 Ys offset{1006};
36 if (y - offset != Y{1307}) return false;
37 if (y - Y{1307} != offset) return false;
38 return true;
39 }
40
main()41 int main()
42 {
43 using year = std::chrono::year;
44 using years = std::chrono::years;
45
46 ASSERT_NOEXCEPT( std::declval<year>() - std::declval<years>());
47 ASSERT_SAME_TYPE(year , decltype(std::declval<year>() - std::declval<years>()));
48
49 ASSERT_NOEXCEPT( std::declval<year>() - std::declval<year>());
50 ASSERT_SAME_TYPE(years, decltype(std::declval<year>() - std::declval<year>()));
51
52 static_assert(testConstexpr<year, years>(), "");
53
54 year y{1223};
55 for (int i = 1100; i <= 1110; ++i)
56 {
57 year y1 = y - years{i};
58 years ys1 = y - year{i};
59 assert(static_cast<int>(y1) == 1223 - i);
60 assert(ys1.count() == 1223 - i);
61 }
62 }
63