xref: /aosp_15_r20/frameworks/native/libs/ftl/non_null_test.cpp (revision 38e8c45f13ce32b0dcecb25141ffecaf386fa17f)
1 /*
2  * Copyright 2022 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 <ftl/algorithm.h>
18 #include <ftl/non_null.h>
19 #include <gtest/gtest.h>
20 
21 #include <memory>
22 #include <set>
23 #include <string>
24 #include <string_view>
25 #include <type_traits>
26 #include <unordered_set>
27 #include <vector>
28 
29 namespace android::test {
30 namespace {
31 
get_length(const ftl::NonNull<std::shared_ptr<std::string>> & string_ptr,ftl::NonNull<std::size_t * > length_ptr)32 void get_length(const ftl::NonNull<std::shared_ptr<std::string>>& string_ptr,
33                 ftl::NonNull<std::size_t*> length_ptr) {
34   // No need for `nullptr` checks.
35   *length_ptr = string_ptr->length();
36 }
37 
38 using Pair = std::pair<ftl::NonNull<std::shared_ptr<int>>, std::shared_ptr<int>>;
39 
dupe_if(ftl::NonNull<std::unique_ptr<int>> non_null_ptr,bool condition)40 Pair dupe_if(ftl::NonNull<std::unique_ptr<int>> non_null_ptr, bool condition) {
41   // Move the underlying pointer out, so `non_null_ptr` must not be accessed after this point.
42   auto unique_ptr = std::move(non_null_ptr).take();
43 
44   auto non_null_shared_ptr = ftl::as_non_null(std::shared_ptr<int>(std::move(unique_ptr)));
45   auto nullable_shared_ptr = condition ? non_null_shared_ptr.get() : nullptr;
46 
47   return {std::move(non_null_shared_ptr), std::move(nullable_shared_ptr)};
48 }
49 
50 }  // namespace
51 
52 // Keep in sync with example usage in header file.
TEST(NonNull,Example)53 TEST(NonNull, Example) {
54   const auto string_ptr = ftl::as_non_null(std::make_shared<std::string>("android"));
55   std::size_t size{};
56   get_length(string_ptr, ftl::as_non_null(&size));
57   EXPECT_EQ(size, 7u);
58 
59   auto ptr = ftl::as_non_null(std::make_unique<int>(42));
60   const auto [ptr1, ptr2] = dupe_if(std::move(ptr), true);
61   EXPECT_EQ(ptr1.get(), ptr2);
62 }
63 
64 namespace {
65 
66 constexpr std::string_view kApple = "apple";
67 constexpr std::string_view kOrange = "orange";
68 
69 using StringViewPtr = ftl::NonNull<const std::string_view*>;
70 constexpr StringViewPtr kApplePtr = ftl::as_non_null(&kApple);
71 constexpr StringViewPtr kOrangePtr = ftl::as_non_null(&kOrange);
72 
longest(StringViewPtr ptr1,StringViewPtr ptr2)73 constexpr StringViewPtr longest(StringViewPtr ptr1, StringViewPtr ptr2) {
74   return ptr1->length() > ptr2->length() ? ptr1 : ptr2;
75 }
76 
77 static_assert(longest(kApplePtr, kOrangePtr) == kOrangePtr);
78 
79 static_assert(static_cast<bool>(kApplePtr));
80 
81 static_assert(std::is_same_v<decltype(ftl::as_non_null(std::declval<const int* const>())),
82                              ftl::NonNull<const int*>>);
83 
84 class Base {};
85 class Derived : public Base {};
86 
87 static_assert(std::is_constructible_v<ftl::NonNull<void*>, ftl::NonNull<int*>>);
88 static_assert(!std::is_constructible_v<ftl::NonNull<int*>, ftl::NonNull<void*>>);
89 static_assert(std::is_constructible_v<ftl::NonNull<const int*>, ftl::NonNull<int*>>);
90 static_assert(!std::is_constructible_v<ftl::NonNull<int*>, ftl::NonNull<const int*>>);
91 static_assert(std::is_constructible_v<ftl::NonNull<Base*>, ftl::NonNull<Derived*>>);
92 static_assert(!std::is_constructible_v<ftl::NonNull<Derived*>, ftl::NonNull<Base*>>);
93 static_assert(std::is_constructible_v<ftl::NonNull<std::unique_ptr<const int>>,
94                                       ftl::NonNull<std::unique_ptr<int>>>);
95 static_assert(std::is_constructible_v<ftl::NonNull<std::unique_ptr<Base>>,
96                                       ftl::NonNull<std::unique_ptr<Derived>>>);
97 
98 static_assert(std::is_assignable_v<ftl::NonNull<void*>, ftl::NonNull<int*>>);
99 static_assert(!std::is_assignable_v<ftl::NonNull<int*>, ftl::NonNull<void*>>);
100 static_assert(std::is_assignable_v<ftl::NonNull<const int*>, ftl::NonNull<int*>>);
101 static_assert(!std::is_assignable_v<ftl::NonNull<int*>, ftl::NonNull<const int*>>);
102 static_assert(std::is_assignable_v<ftl::NonNull<Base*>, ftl::NonNull<Derived*>>);
103 static_assert(!std::is_assignable_v<ftl::NonNull<Derived*>, ftl::NonNull<Base*>>);
104 static_assert(std::is_assignable_v<ftl::NonNull<std::unique_ptr<const int>>,
105                                    ftl::NonNull<std::unique_ptr<int>>>);
106 static_assert(std::is_assignable_v<ftl::NonNull<std::unique_ptr<Base>>,
107                                    ftl::NonNull<std::unique_ptr<Derived>>>);
108 
109 }  // namespace
110 
TEST(NonNull,SwapRawPtr)111 TEST(NonNull, SwapRawPtr) {
112   int i1 = 123;
113   int i2 = 456;
114   auto ptr1 = ftl::as_non_null(&i1);
115   auto ptr2 = ftl::as_non_null(&i2);
116 
117   std::swap(ptr1, ptr2);
118 
119   EXPECT_EQ(*ptr1, 456);
120   EXPECT_EQ(*ptr2, 123);
121 }
122 
TEST(NonNull,SwapSmartPtr)123 TEST(NonNull, SwapSmartPtr) {
124   auto ptr1 = ftl::as_non_null(std::make_shared<int>(123));
125   auto ptr2 = ftl::as_non_null(std::make_shared<int>(456));
126 
127   std::swap(ptr1, ptr2);
128 
129   EXPECT_EQ(*ptr1, 456);
130   EXPECT_EQ(*ptr2, 123);
131 }
132 
TEST(NonNull,VectorOfRawPtr)133 TEST(NonNull, VectorOfRawPtr) {
134   int i = 1;
135   std::vector<ftl::NonNull<int*>> vpi;
136   vpi.push_back(ftl::as_non_null(&i));
137   EXPECT_FALSE(ftl::contains(vpi, nullptr));
138   EXPECT_TRUE(ftl::contains(vpi, &i));
139   EXPECT_TRUE(ftl::contains(vpi, vpi.front()));
140 }
141 
TEST(NonNull,VectorOfSmartPtr)142 TEST(NonNull, VectorOfSmartPtr) {
143   std::vector<ftl::NonNull<std::shared_ptr<int>>> vpi;
144   vpi.push_back(ftl::as_non_null(std::make_shared<int>(2)));
145   EXPECT_FALSE(ftl::contains(vpi, nullptr));
146   EXPECT_TRUE(ftl::contains(vpi, vpi.front().get()));
147   EXPECT_TRUE(ftl::contains(vpi, vpi.front()));
148 }
149 
TEST(NonNull,SetOfRawPtr)150 TEST(NonNull, SetOfRawPtr) {
151   int i = 1;
152   std::set<ftl::NonNull<int*>> spi;
153   spi.insert(ftl::as_non_null(&i));
154   EXPECT_FALSE(ftl::contains(spi, nullptr));
155   EXPECT_TRUE(ftl::contains(spi, &i));
156   EXPECT_TRUE(ftl::contains(spi, *spi.begin()));
157 }
158 
TEST(NonNull,SetOfSmartPtr)159 TEST(NonNull, SetOfSmartPtr) {
160   std::set<ftl::NonNull<std::shared_ptr<int>>> spi;
161   spi.insert(ftl::as_non_null(std::make_shared<int>(2)));
162   EXPECT_FALSE(ftl::contains(spi, nullptr));
163   EXPECT_TRUE(ftl::contains(spi, spi.begin()->get()));
164   EXPECT_TRUE(ftl::contains(spi, *spi.begin()));
165 }
166 
TEST(NonNull,UnorderedSetOfRawPtr)167 TEST(NonNull, UnorderedSetOfRawPtr) {
168   int i = 1;
169   std::unordered_set<ftl::NonNull<int*>> spi;
170   spi.insert(ftl::as_non_null(&i));
171   EXPECT_FALSE(ftl::contains(spi, nullptr));
172   EXPECT_TRUE(ftl::contains(spi, &i));
173   EXPECT_TRUE(ftl::contains(spi, *spi.begin()));
174 }
175 
TEST(NonNull,UnorderedSetOfSmartPtr)176 TEST(NonNull, UnorderedSetOfSmartPtr) {
177   std::unordered_set<ftl::NonNull<std::shared_ptr<int>>> spi;
178   spi.insert(ftl::as_non_null(std::make_shared<int>(2)));
179   EXPECT_FALSE(ftl::contains(spi, nullptr));
180   EXPECT_TRUE(ftl::contains(spi, spi.begin()->get()));
181   EXPECT_TRUE(ftl::contains(spi, *spi.begin()));
182 }
183 
TEST(NonNull,ImplicitConversion)184 TEST(NonNull, ImplicitConversion) {
185   int i = 123;
186   int j = 345;
187   auto ip = ftl::as_non_null(&i);
188   ftl::NonNull<void*> vp{ip};
189   EXPECT_EQ(vp.get(), &i);
190   vp = ftl::as_non_null(&j);
191   EXPECT_EQ(vp.get(), &j);
192 }
193 
194 }  // namespace android::test
195