libstdc++-v3/testsuite/std/time/traits/is_clock.cc

   1 // Copyright (C) 2020-2023 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-do compile { target c++20 } }
  19
  20 #include <chrono>
  21 #include <slow_clock.h>
  22
  23 namespace chrono = std::chrono;
  24
  25 static_assert( chrono::is_clock<chrono::system_clock>::value );
  26 static_assert( chrono::is_clock_v<chrono::system_clock> );
  27
  28 static_assert( chrono::is_clock<chrono::high_resolution_clock>::value );
  29 static_assert( chrono::is_clock_v<chrono::high_resolution_clock> );
  30
  31 static_assert( chrono::is_clock<chrono::steady_clock>::value );
  32 static_assert( chrono::is_clock_v<chrono::steady_clock> );
  33
  34 static_assert(chrono::is_clock<chrono::file_clock>::value);
  35 static_assert(chrono::is_clock_v<chrono::file_clock>);
  36
  37 // Clock<xxx_clock> will not use the specialization of is_clock<xxx_clock>
  38 template<typename C> struct Clock : C { };
  39
  40 static_assert( chrono::is_clock<Clock<chrono::system_clock>>::value );
  41 static_assert( chrono::is_clock_v<Clock<chrono::system_clock>> );
  42
  43 static_assert( chrono::is_clock<Clock<chrono::high_resolution_clock>>::value );
  44 static_assert( chrono::is_clock_v<Clock<chrono::high_resolution_clock>> );
  45
  46 static_assert( chrono::is_clock<Clock<chrono::steady_clock>>::value );
  47 static_assert( chrono::is_clock_v<Clock<chrono::steady_clock>> );
  48
  49 static_assert(chrono::is_clock<Clock<chrono::file_clock>>::value);
  50 static_assert(chrono::is_clock_v<Clock<chrono::file_clock>>);
  51
  52 static_assert( chrono::is_clock<__gnu_test::slow_clock>::value );
  53 static_assert( chrono::is_clock_v<__gnu_test::slow_clock> );
  54
  55 // Negative tests
  56
  57 static_assert( ! chrono::is_clock<int>::value );
  58 static_assert( ! chrono::is_clock_v<int> );
  59
  60 static_assert( ! chrono::is_clock<void>::value );
  61 static_assert( ! chrono::is_clock_v<void> );
  62
  63 struct not_a_clock_1
  64 {
  65   using rep = int;
  66   using period = std::ratio<4, 2>;
  67   using duration = chrono::duration<long, period>; // different rep
  68   using time_point = chrono::time_point<not_a_clock_1>;
  69   static constexpr bool is_steady = false;
  70   static time_point now();
  71 };
  72
  73 static_assert( ! chrono::is_clock<not_a_clock_1>::value );
  74 static_assert( ! chrono::is_clock_v<not_a_clock_1> );
  75
  76 struct not_a_clock_2
  77 {
  78   using rep = int;
  79   using period = int; // not a std::ratio
  80   using duration = chrono::duration<rep>;
  81   using time_point = chrono::time_point<not_a_clock_2>;
  82   static constexpr bool is_steady = false;
  83   static time_point now();
  84 };
  85
  86 static_assert( ! chrono::is_clock<not_a_clock_2>::value );
  87 static_assert( ! chrono::is_clock_v<not_a_clock_2> );
  88
  89 struct not_a_clock_3
  90 {
  91   using rep = int;
  92   using period = std::ratio<1>;
  93   using duration = chrono::duration<rep>;
  94   // wrong duration:
  95   using time_point = chrono::time_point<not_a_clock_3, chrono::duration<long>>;
  96   static constexpr bool is_steady = false;
  97   static time_point now();
  98 };
  99
 100 static_assert( ! chrono::is_clock<not_a_clock_3>::value );
 101 static_assert( ! chrono::is_clock_v<not_a_clock_3> );
 102
 103 struct not_a_clock_4
 104 {
 105   using rep = int;
 106   using period = std::ratio<1>;
 107   using duration = chrono::duration<rep>;
 108   using time_point = chrono::time_point<not_a_clock_4>;
 109   static constexpr int is_steady = 0; // not a const bool
 110   static time_point now();
 111 };
 112
 113 static_assert( ! chrono::is_clock<not_a_clock_4>::value );
 114 static_assert( ! chrono::is_clock_v<not_a_clock_4> );
 115
 116 struct not_a_clock_5
 117 {
 118   using rep = int;
 119   using period = std::ratio<1>;
 120   using duration = chrono::duration<rep>;
 121   using time_point = chrono::time_point<not_a_clock_5>;
 122   static constexpr bool is_steady = false;
 123   static int now(); // wrong return type
 124 };
 125
 126 static_assert( ! chrono::is_clock<not_a_clock_5>::value );
 127 static_assert( ! chrono::is_clock_v<not_a_clock_5> );
 128
 129 struct not_a_clock_6
 130 {
 131   using rep = int;
 132   using period = std::ratio<1>;
 133   using duration = chrono::duration<rep>;
 134   using time_point = chrono::time_point<not_a_clock_6>;
 135   const bool is_steady = false; // not static
 136   static time_point now();
 137 };
 138
 139 static_assert( ! chrono::is_clock<not_a_clock_6>::value );
 140 static_assert( ! chrono::is_clock_v<not_a_clock_6> );