Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/src/include/scope_guard.h b/src/include/scope_guard.h
new file mode 100644
index 000000000..eacc65e7b
--- /dev/null
+++ b/src/include/scope_guard.h
@@ -0,0 +1,49 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2016 Red Hat
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef SCOPE_GUARD
+#define SCOPE_GUARD
+
+#include <utility>
+
+template <typename F>
+struct scope_guard {
+  F f;
+  scope_guard() = delete;
+  scope_guard(const scope_guard &) = delete;
+  scope_guard(scope_guard &&) = default;
+  scope_guard & operator=(const scope_guard &) = delete;
+  scope_guard & operator=(scope_guard &&) = default;
+  scope_guard(const F& f) : f(f) {}
+  scope_guard(F &&f) : f(std::move(f)) {}
+  template<typename... Args>
+  scope_guard(std::in_place_t, Args&& ...args) : f(std::forward<Args>(args)...) {}
+  ~scope_guard() {
+    std::move(f)(); // Support at-most-once functions
+  }
+};
+
+template <typename F>
+[[nodiscard("Unassigned scope guards will execute immediately")]]
+scope_guard<F> make_scope_guard(F &&f) {
+  return scope_guard<F>(std::forward<F>(f));
+}
+
+template<typename F, typename... Args>
+[[nodiscard("Unassigned scope guards will execute immediately")]]
+scope_guard<F> make_scope_guard(std::in_place_type_t<F>, Args&& ...args) {
+  return { std::in_place, std::forward<Args>(args)... };
+}
+
+#endif