ceph/src/zstd/contrib/pzstd/utils/ScopeGuard.h

   1 /*
   2  * Copyright (c) 2016-present, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under both the BSD-style license (found in the
   6  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
   7  * in the COPYING file in the root directory of this source tree).
   8  */
   9 #pragma once
  10
  11 #include <utility>
  12
  13 namespace pzstd {
  14
  15 /**
  16  * Dismissable scope guard.
  17  * `Function` must be callable and take no parameters.
  18  * Unless `dissmiss()` is called, the callable is executed upon destruction of
  19  * `ScopeGuard`.
  20  *
  21  * Example:
  22  *
  23  *   auto guard = makeScopeGuard([&] { cleanup(); });
  24  */
  25 template <typename Function>
  26 class ScopeGuard {
  27   Function function;
  28   bool dismissed;
  29
  30  public:
  31   explicit ScopeGuard(Function&& function)
  32       : function(std::move(function)), dismissed(false) {}
  33
  34   void dismiss() {
  35     dismissed = true;
  36   }
  37
  38   ~ScopeGuard() noexcept {
  39     if (!dismissed) {
  40       function();
  41     }
  42   }
  43 };
  44
  45 /// Creates a scope guard from `function`.
  46 template <typename Function>
  47 ScopeGuard<Function> makeScopeGuard(Function&& function) {
  48   return ScopeGuard<Function>(std::forward<Function>(function));
  49 }
  50 }