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 month; 13 14 // constexpr month operator-(const month& x, const months& y) noexcept; 15 // Returns: x + -y. 16 // 17 // constexpr months operator-(const month& x, const month& y) noexcept; 18 // Returns: If x.ok() == true and y.ok() == true, returns a value m in the range 19 // [months{0}, months{11}] satisfying y + m == x. 20 // Otherwise the value returned is unspecified. 21 // [Example: January - February == months{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 M, typename Ms> 32 constexpr bool testConstexpr() 33 { 34 { 35 M m{5}; 36 Ms offset{3}; 37 if (m - offset != M{2}) return false; 38 if (m - M{2} != offset) return false; 39 } 40 41 // Check the example 42 if (M{1} - M{2} != Ms{11}) return false; 43 return true; 44 } 45 46 #include <iostream> 47 48 int main() 49 { 50 using month = std::chrono::month; 51 using months = std::chrono::months; 52 53 ASSERT_NOEXCEPT(std::declval<month>() - std::declval<months>()); 54 ASSERT_NOEXCEPT(std::declval<month>() - std::declval<month>()); 55 56 ASSERT_SAME_TYPE(month , decltype(std::declval<month>() - std::declval<months>())); 57 ASSERT_SAME_TYPE(months, decltype(std::declval<month>() - std::declval<month> ())); 58 59 static_assert(testConstexpr<month, months>(), ""); 60 61 month m{6}; 62 for (unsigned i = 1; i <= 12; ++i) 63 { 64 month m1 = m - months{i}; 65 // months off = m - month {i}; 66 int exp = 6 - i; 67 if (exp < 1) 68 exp += 12; 69 assert(static_cast<unsigned>(m1) == static_cast<unsigned>(exp)); 70 // assert(off.count() == static_cast<unsigned>(exp)); 71 } 72 } 73
