Tests: add a test for Threads::InitializationCheck

tests/base/initialization_check_01.cc

@@ -0,0 +1,68 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2005 - 2021 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, redistribute
+// it, and/or modify it under the terms of the GNU Lesser General
+// Public License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE.md at
+// the top level directory of deal.II.
+//
+// ---------------------------------------------------------------------
+
+
+// check numbers::is_finite
+
+#include <deal.II/base/initialization_check.h>
+
+#include <iostream>
+
+#include "../tests.h"
+
+using namespace dealii;
+
+class Consumer
+{
+public:
+  void
+  do_something()
+  {
+    deallog << "called do_something" << std::endl;
+    initialization_check.check_and_initialize(
+      [&]() { deallog << "called initializer" << std::endl; });
+  }
+
+private:
+  Threads::InitializationCheck initialization_check;
+};
+
+int
+main()
+{
+  initlog();
+
+  deallog << "consumer_1:" << std::endl;
+  Consumer consumer_1;
+  consumer_1.do_something();
+  consumer_1.do_something();
+
+  deallog << "consumer_2 (copy constructed, already initialized):" << std::endl;
+  auto consumer_2 = consumer_1;
+  consumer_2.do_something();
+
+  deallog << "consumer_3:" << std::endl;
+  Consumer consumer_3;
+  consumer_3.do_something();
+  deallog << "consumer_3 (copy assignment, already initialized):" << std::endl;
+  consumer_3 = consumer_1;
+  consumer_3.do_something();
+  deallog << "consumer_3 (move assignment, uninitialized):" << std::endl;
+  consumer_3 = Consumer();
+  consumer_3.do_something();
+
+  deallog << "OK!" << std::endl;
+  return 0;
+}

tests/base/initialization_check_01.output

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+
+DEAL::consumer_1:
+DEAL::called do_something
+DEAL::called initializer
+DEAL::called do_something
+DEAL::consumer_2 (copy constructed, already initialized):
+DEAL::called do_something
+DEAL::consumer_3:
+DEAL::called do_something
+DEAL::called initializer
+DEAL::consumer_3 (copy assignment, already initialized):
+DEAL::called do_something
+DEAL::consumer_3 (move assignment, uninitialized):
+DEAL::called do_something
+DEAL::called initializer
+DEAL::OK!