1 //===-- Unittests for Optional --------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "src/__support/CPP/optional.h"
10 #include "test/UnitTest/Test.h"
11
12 using LIBC_NAMESPACE::cpp::nullopt;
13 using LIBC_NAMESPACE::cpp::optional;
14
15 // This class has three properties for testing:
16 // 1) No default constructor.
17 // 2) A non-trivial destructor with an observable side-effect.
18 // 3) Functions that can be called explicitly.
19 class Contrived {
20 int *_a;
21
22 public:
Contrived(int * a)23 Contrived(int *a) : _a(a) {}
~Contrived()24 ~Contrived() { (*_a)++; }
25
get_a()26 int get_a() { return *_a; }
inc_a()27 void inc_a() { (*_a)++; }
28 };
29
TEST(LlvmLibcOptionalTest,Tests)30 TEST(LlvmLibcOptionalTest, Tests) {
31 optional<int> Trivial1(12);
32 ASSERT_TRUE(Trivial1.has_value());
33 ASSERT_EQ(Trivial1.value(), 12);
34 ASSERT_EQ(*Trivial1, 12);
35 Trivial1.reset();
36 ASSERT_FALSE(Trivial1.has_value());
37
38 optional<int> Trivial2(12);
39 ASSERT_TRUE(Trivial2.has_value());
40 Trivial2 = nullopt;
41 ASSERT_FALSE(Trivial2.has_value());
42
43 // For this test case, the destructor increments the pointed-to value.
44 int holding = 1;
45 {
46 optional<Contrived> Complicated(&holding);
47 // Destructor was run once as part of copying the object.
48 ASSERT_EQ(holding, 2);
49 // Destructor was run a second time as part of destruction.
50 Complicated.reset();
51 ASSERT_EQ(holding, 3);
52 // Destructor was not run a third time as the object is already destroyed.
53 Complicated.reset();
54 ASSERT_EQ(holding, 3);
55 }
56 // Make sure the destructor isn't called when the optional is destroyed.
57 ASSERT_EQ(holding, 3);
58
59 // Test that assigning an optional to another works when set
60 optional<int> Trivial3(12);
61 optional<int> Trivial4 = Trivial3;
62 ASSERT_TRUE(Trivial4.has_value());
63 ASSERT_EQ(Trivial4.value(), 12);
64
65 // Test that assigning an option to another works when unset
66 optional<int> Trivial5;
67 ASSERT_FALSE(Trivial5.has_value());
68 optional<int> Trivial6 = Trivial5;
69 ASSERT_FALSE(Trivial6.has_value());
70
71 // Test operator->
72 int arrow_num = 5;
73 optional<Contrived> arrow_test(&arrow_num);
74 ASSERT_TRUE(arrow_test.has_value());
75 ASSERT_EQ(arrow_test->get_a(), arrow_num);
76 arrow_num = 10;
77 ASSERT_EQ(arrow_test->get_a(), arrow_num);
78 arrow_test->inc_a();
79 ASSERT_EQ(arrow_test->get_a(), arrow_num);
80 ASSERT_EQ(arrow_num, 11);
81 arrow_test.reset();
82 }
83