1 files changed, 124 insertions, 0 deletions
diff --git a/libstdc++-v3/testsuite/std/time/traits/is_clock.cc b/libstdc++-v3/testsuite/std/time/traits/is_clock.cc
new file mode 100644
index 00000000000..85f118253c3
--- /dev/null
+++ b/libstdc++-v3/testsuite/std/time/traits/is_clock.cc
@@ -0,0 +1,124 @@
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <chrono>
+#include <slow_clock.h>
+
+namespace chrono = std::chrono;
+
+static_assert( chrono::is_clock<chrono::system_clock>::value );
+static_assert( chrono::is_clock_v<chrono::system_clock> );
+
+static_assert( chrono::is_clock<chrono::high_resolution_clock>::value );
+static_assert( chrono::is_clock_v<chrono::high_resolution_clock> );
+
+static_assert( chrono::is_clock<chrono::steady_clock>::value );
+static_assert( chrono::is_clock_v<chrono::steady_clock> );
+
+static_assert(chrono::is_clock<chrono::file_clock>::value);
+static_assert(chrono::is_clock_v<chrono::file_clock>);
+
+static_assert( chrono::is_clock<__gnu_test::slow_clock>::value );
+static_assert( chrono::is_clock_v<__gnu_test::slow_clock> );
+
+static_assert( ! chrono::is_clock<int>::value );
+static_assert( ! chrono::is_clock_v<int> );
+
+static_assert( ! chrono::is_clock<void>::value );
+static_assert( ! chrono::is_clock_v<void> );
+
+struct not_a_clock_1
+{
+  using rep = int;
+  using period = std::ratio<4, 2>;
+  using duration = chrono::duration<long, period>; // different rep
+  using time_point = chrono::time_point<not_a_clock_1>;
+  static constexpr bool is_steady = false;
+  static time_point now();
+};
+
+static_assert( ! chrono::is_clock<not_a_clock_1>::value );
+static_assert( ! chrono::is_clock_v<not_a_clock_1> );
+
+struct not_a_clock_2
+{
+  using rep = int;
+  using period = int; // not a std::ratio
+  using duration = chrono::duration<rep>;
+  using time_point = chrono::time_point<not_a_clock_2>;
+  static constexpr bool is_steady = false;
+  static time_point now();
+};
+
+static_assert( ! chrono::is_clock<not_a_clock_2>::value );
+static_assert( ! chrono::is_clock_v<not_a_clock_2> );
+
+struct not_a_clock_3
+{
+  using rep = int;
+  using period = std::ratio<1>;
+  using duration = chrono::duration<rep>;
+  // wrong duration:
+  using time_point = chrono::time_point<not_a_clock_3, chrono::duration<long>>;
+  static constexpr bool is_steady = false;
+  static time_point now();
+};
+
+static_assert( ! chrono::is_clock<not_a_clock_3>::value );
+static_assert( ! chrono::is_clock_v<not_a_clock_3> );
+
+struct not_a_clock_4
+{
+  using rep = int;
+  using period = std::ratio<1>;
+  using duration = chrono::duration<rep>;
+  using time_point = chrono::time_point<not_a_clock_4>;
+  static constexpr int is_steady = 0; // not a const bool
+  static time_point now();
+};
+
+static_assert( ! chrono::is_clock<not_a_clock_4>::value );
+static_assert( ! chrono::is_clock_v<not_a_clock_4> );
+
+struct not_a_clock_5
+{
+  using rep = int;
+  using period = std::ratio<1>;
+  using duration = chrono::duration<rep>;
+  using time_point = chrono::time_point<not_a_clock_5>;
+  static constexpr bool is_steady = false;
+  static int now(); // wrong return type
+};
+
+static_assert( ! chrono::is_clock<not_a_clock_5>::value );
+static_assert( ! chrono::is_clock_v<not_a_clock_5> );
+
+struct not_a_clock_6
+{
+  using rep = int;
+  using period = std::ratio<1>;
+  using duration = chrono::duration<rep>;
+  using time_point = chrono::time_point<not_a_clock_6>;
+  const bool is_steady = false; // not static
+  static time_point now();
+};
+
+static_assert( ! chrono::is_clock<not_a_clock_6>::value );
+static_assert( ! chrono::is_clock_v<not_a_clock_6> );