Mir
cached_ptr.h
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1 /*
2  * Copyright © 2013 Canonical Ltd.
3  *
4  * This program is free software: you can redistribute it and/or modify
5  * it under the terms of the GNU Lesser General Public License version 2 or 3 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU Lesser General Public License for more details.
12  *
13  * You should have received a copy of the GNU Lesser General Public License
14  * along with this program. If not, see <http://www.gnu.org/licenses/>.
15  *
16  * Authored by: Robert Carr <robert.carr@canonical.com>
17  */
18 
19 #ifndef MIR_CACHED_PTR_H_
20 #define MIR_CACHED_PTR_H_
21 
22 #include <functional>
23 #include <memory>
24 
25 namespace mir
26 {
27 template<typename Type>
28 class CachedPtr
29 {
30  std::weak_ptr<Type> cache;
31  CachedPtr(CachedPtr const&) = delete;
32  CachedPtr& operator=(CachedPtr const&) = delete;
33 public:
34  CachedPtr() = default;
35 
36  std::shared_ptr<Type> operator()(std::function<std::shared_ptr<Type>()> make)
37  {
38  auto result = cache.lock();
39  if (!result)
40  {
41  cache = result = make();
42  }
43  return result;
44  }
45 };
46 } // namespace mir
47 
48 #endif // MIR_CACHED_PTR_H_
AutoUnblockThread is a helper thread class that can gracefully shutdown at destruction time...
Definition: blob.h:26
Definition: cached_ptr.h:28
std::shared_ptr< Type > operator()(std::function< std::shared_ptr< Type >()> make)
Definition: cached_ptr.h:36
CachedPtr()=default

Copyright © 2012-2018 Canonical Ltd.
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