blob: c6295117e51ea3b829501744fb7524b03b18d63f [file] [log] [blame]
Ilya Matyukhin4f5d6802021-02-22 13:10:55 -08001/*
2 * Copyright (C) 2021 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#pragma once
18
19namespace aidl::android::hardware::biometrics::fingerprint {
20
21// Interface for representing parameterless functions. Unlike std::function<void()>, this can also
22// represent move-only lambdas.
23class Callable {
24 public:
25 virtual void operator()() = 0;
26 virtual ~Callable() = default;
27
28 // Creates a heap-allocated Callable instance from any function object.
29 template <typename T>
30 static std::unique_ptr<Callable> from(T func);
31
32 private:
33 template <typename T>
34 class AnyFuncWrapper;
35};
36
37// Private helper class for wrapping any function object into a Callable.
38template <typename T>
39class Callable::AnyFuncWrapper : public Callable {
40 public:
41 explicit AnyFuncWrapper(T func) : mFunc(std::move(func)) {}
42
43 void operator()() override { mFunc(); }
44
45 private:
46 T mFunc;
47};
48
49template <typename T>
50std::unique_ptr<Callable> Callable::from(T func) {
51 return std::make_unique<AnyFuncWrapper<T>>(std::move(func));
52}
53
54} // namespace aidl::android::hardware::biometrics::fingerprint