1 /*
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 #include "android-base/function_ref.h"
18
19 #include <gtest/gtest.h>
20
21 #include <functional>
22 #include <string>
23
24 namespace android::base {
25
TEST(function_ref,Ctor)26 TEST(function_ref, Ctor) {
27 // Making sure it can be constructed in all meaningful ways
28
29 using EmptyFunc = function_ref<void()>;
30
31 EmptyFunc f1([] {});
32
33 struct Functor {
34 void operator()() const {}
35 };
36 EmptyFunc f2(Functor{});
37 Functor fctr;
38 EmptyFunc f3(fctr);
39
40 EmptyFunc f4(std::function<void()>([f1, f2, f3] {
41 (void)f1;
42 (void)f2;
43 (void)f3;
44 }));
45
46 const std::function<void()> func = [] {};
47 EmptyFunc f5(func);
48
49 static_assert(sizeof(f1) <= 2 * sizeof(void*), "Too big function_ref");
50 static_assert(sizeof(f2) <= 2 * sizeof(void*), "Too big function_ref");
51 static_assert(sizeof(f3) <= 2 * sizeof(void*), "Too big function_ref");
52 static_assert(sizeof(f4) <= 2 * sizeof(void*), "Too big function_ref");
53 static_assert(sizeof(f5) <= 2 * sizeof(void*), "Too big function_ref");
54 }
55
TEST(function_ref,Call)56 TEST(function_ref, Call) {
57 function_ref<int(int)> view = [](int i) { return i + 1; };
58 EXPECT_EQ(1, view(0));
59 EXPECT_EQ(-1, view(-2));
60
61 function_ref<std::string(std::string)> fs = [](const std::string& s) { return s + "1"; };
62 EXPECT_STREQ("s1", fs("s").c_str());
63 EXPECT_STREQ("ssss1", fs("ssss").c_str());
64
65 std::string base;
66 auto lambda = [&base]() { return base + "1"; };
67 function_ref<std::string()> fs2 = lambda;
68 base = "one";
69 EXPECT_STREQ("one1", fs2().c_str());
70 base = "forty two";
71 EXPECT_STREQ("forty two1", fs2().c_str());
72 }
73
TEST(function_ref,CopyAndAssign)74 TEST(function_ref, CopyAndAssign) {
75 function_ref<int(int)> view = [](int i) { return i + 1; };
76 EXPECT_EQ(1, view(0));
77 view = [](int i) { return i - 1; };
78 EXPECT_EQ(0, view(1));
79
80 function_ref<int(int)> view2 = view;
81 EXPECT_EQ(view(10), view2(10));
82
83 view = view2;
84 EXPECT_EQ(view(10), view2(10));
85 }
86
87 } // namespace android::base
88