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 weekday;
12
13 // constexpr weekday operator-(const weekday& x, const days& y) noexcept;
14 // Returns: x + -y.
15 //
16 // constexpr days operator-(const weekday& x, const weekday& y) noexcept;
17 // Returns: If x.ok() == true and y.ok() == true, returns a value d in the range
18 // [days{0}, days{6}] satisfying y + d == x.
19 // Otherwise the value returned is unspecified.
20 // [Example: Sunday - Monday == days{6}. —end example]
21
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 #include "../../euclidian.h"
31
32 template <typename WD, typename Ds>
testConstexpr()33 constexpr bool testConstexpr()
34 {
35 {
36 WD wd{5};
37 Ds offset{3};
38 if (wd - offset != WD{2}) return false;
39 if (wd - WD{2} != offset) return false;
40 }
41
42 // Check the example
43 if (WD{0} - WD{1} != Ds{6}) return false;
44 return true;
45 }
46
main(int,char **)47 int main(int, char**)
48 {
49 using weekday = std::chrono::weekday;
50 using days = std::chrono::days;
51
52 ASSERT_NOEXCEPT( std::declval<weekday>() - std::declval<days>());
53 ASSERT_SAME_TYPE(weekday, decltype(std::declval<weekday>() - std::declval<days>()));
54
55 ASSERT_NOEXCEPT( std::declval<weekday>() - std::declval<weekday>());
56 ASSERT_SAME_TYPE(days, decltype(std::declval<weekday>() - std::declval<weekday>()));
57
58 static_assert(testConstexpr<weekday, days>(), "");
59
60 for (unsigned i = 0; i <= 6; ++i)
61 for (unsigned j = 0; j <= 6; ++j)
62 {
63 weekday wd = weekday{i} - days{j};
64 assert(wd + days{j} == weekday{i});
65 assert((wd.c_encoding() == euclidian_subtraction<unsigned, 0, 6>(i, j)));
66 }
67
68 for (unsigned i = 0; i <= 6; ++i)
69 for (unsigned j = 0; j <= 6; ++j)
70 {
71 days d = weekday{j} - weekday{i};
72 assert(weekday{i} + d == weekday{j});
73 }
74
75
76 return 0;
77 }
78