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_month_day; 13 14 // constexpr operator local_days() const noexcept; 15 // 16 // Returns: If ok(), returns a local_days holding a count of days from the 17 // local_days epoch to *this (a negative value if *this represents a date 18 // prior to the sys_days epoch). Otherwise, if y_.ok() && m_.ok() is true, 19 // returns a sys_days which is offset from sys_days{y_/m_/last} by the 20 // number of days d_ is offset from sys_days{y_/m_/last}.day(). Otherwise 21 // the value returned is unspecified. 22 // 23 // Remarks: A local_days in the range [days{-12687428}, days{11248737}] which 24 // is converted to a year_month_day shall have the same value when 25 // converted back to a sys_days. 26 // 27 // [Example: 28 // static_assert(year_month_day{local_days{2017y/January/0}} == 2016y/December/31); 29 // static_assert(year_month_day{local_days{2017y/January/31}} == 2017y/January/31); 30 // static_assert(year_month_day{local_days{2017y/January/32}} == 2017y/February/1); 31 // end example] 32 33 #include <chrono> 34 #include <type_traits> 35 #include <cassert> 36 37 #include "test_macros.h" 38 39 void RunTheExample() 40 { 41 using namespace std::chrono; 42 43 static_assert(year_month_day{local_days{year{2017}/January/0}} == year{2016}/December/31); 44 static_assert(year_month_day{local_days{year{2017}/January/31}} == year{2017}/January/31); 45 static_assert(year_month_day{local_days{year{2017}/January/32}} == year{2017}/February/1); 46 } 47 48 int main() 49 { 50 using year = std::chrono::year; 51 using month = std::chrono::month; 52 using day = std::chrono::day; 53 using local_days = std::chrono::local_days; 54 using days = std::chrono::days; 55 using year_month_day = std::chrono::year_month_day; 56 57 ASSERT_NOEXCEPT(local_days(std::declval<year_month_day>())); 58 RunTheExample(); 59 60 { 61 constexpr year_month_day ymd{year{1970}, month{1}, day{1}}; 62 constexpr local_days sd{ymd}; 63 64 static_assert( sd.time_since_epoch() == days{0}, ""); 65 static_assert( year_month_day{sd} == ymd, ""); // and back 66 } 67 68 { 69 constexpr year_month_day ymd{year{2000}, month{2}, day{2}}; 70 constexpr local_days sd{ymd}; 71 72 static_assert( sd.time_since_epoch() == days{10957+32}, ""); 73 static_assert( year_month_day{sd} == ymd, ""); // and back 74 } 75 76 // There's one more leap day between 1/1/40 and 1/1/70 77 // when compared to 1/1/70 -> 1/1/2000 78 { 79 constexpr year_month_day ymd{year{1940}, month{1}, day{2}}; 80 constexpr local_days sd{ymd}; 81 82 static_assert( sd.time_since_epoch() == days{-10957}, ""); 83 static_assert( year_month_day{sd} == ymd, ""); // and back 84 } 85 86 { 87 year_month_day ymd{year{1939}, month{11}, day{29}}; 88 local_days sd{ymd}; 89 90 assert( sd.time_since_epoch() == days{-(10957+34)}); 91 assert( year_month_day{sd} == ymd); // and back 92 } 93 94 } 95
