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
9// UNSUPPORTED: c++03, c++11, c++14, c++17
10
11// UNSUPPORTED: availability-filesystem-missing
12
13// <chrono>
14//
15// file_clock
16//
17// template<class Duration>
18// static sys_time<see-below> to_sys(const file_time<Duration>&);
19//
20// template<class Duration>
21// static file_time<see-below> from_sys(const sys_time<Duration>&);
22
23#include <chrono>
24#include <cassert>
25
26int main(int, char**) {
27 // Test round-trip through the system clock, starting from file_clock::now()
28 {
29 std::chrono::file_clock::time_point const ft = std::chrono::file_clock::now();
30 auto st = std::chrono::file_clock::to_sys(ft);
31 assert(ft == std::chrono::file_clock::from_sys(st));
32 }
33
34 // Test round-trip through the system clock, starting from system_clock::now()
35 {
36 std::chrono::system_clock::time_point const st = std::chrono::system_clock::now();
37 auto ft = std::chrono::file_clock::from_sys(st);
38 assert(st == std::chrono::file_clock::to_sys(ft));
39 }
40
41 // Make sure the value we get is in the ballpark of something reasonable
42 {
43 std::chrono::file_clock::time_point const file_now = std::chrono::file_clock::now();
44 std::chrono::system_clock::time_point const sys_now = std::chrono::system_clock::now();
45 {
46 auto diff = sys_now - std::chrono::file_clock::to_sys(file_now);
47 assert(std::chrono::milliseconds(-500) < diff && diff < std::chrono::milliseconds(500));
48 }
49 {
50 auto diff = std::chrono::file_clock::from_sys(sys_now) - file_now;
51 assert(std::chrono::milliseconds(-500) < diff && diff < std::chrono::milliseconds(500));
52 }
53 }
54
55 // Make sure to_sys and from_sys are consistent with each other
56 {
57 std::chrono::file_clock::time_point const ft = std::chrono::file_clock::now();
58 std::chrono::system_clock::time_point const st = std::chrono::system_clock::now();
59 auto sys_diff = std::chrono::file_clock::to_sys(ft) - st;
60 auto file_diff = ft - std::chrono::file_clock::from_sys(st);
61 assert(sys_diff == file_diff);
62 }
63
64 return 0;
65}
66

source code of libcxx/test/std/time/time.clock/time.clock.file/to_from_sys.pass.cpp