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3** Copyright (C) 2018 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Sérgio Martins <sergio.martins@kdab.com>
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29
30#include <QtTest/QtTest>
31#include <QtCore/QScopeGuard>
32
33/*!
34 \class tst_QScopeGuard
35 \internal
36 \since 5.11
37 \brief Tests class QScopeGuard and function qScopeGuard
38
39 */
40class tst_QScopeGuard : public QObject
41{
42 Q_OBJECT
43
44private Q_SLOTS:
45 void construction();
46 void constructionFromLvalue();
47 void constructionFromRvalue();
48 void leavingScope();
49 void exceptions();
50};
51
52void func()
53{
54}
55
56int intFunc()
57{
58 return 0;
59}
60
61Q_REQUIRED_RESULT int noDiscardFunc()
62{
63 return 0;
64}
65
66struct Callable
67{
68 Callable() { }
69 Callable(const Callable &other)
70 {
71 Q_UNUSED(other);
72 ++copied;
73 }
74 Callable(Callable &&other)
75 {
76 Q_UNUSED(other);
77 ++moved;
78 }
79 void operator()() { }
80
81 static int copied;
82 static int moved;
83 static void resetCounts()
84 {
85 copied = 0;
86 moved = 0;
87 }
88};
89
90int Callable::copied = 0;
91int Callable::moved = 0;
92
93static int s_globalState = 0;
94
95void tst_QScopeGuard::construction()
96{
97#ifdef __cpp_deduction_guides
98 QScopeGuard fromLambda([] { });
99 QScopeGuard fromFunction(func);
100 QScopeGuard fromFunctionPointer(&func);
101 QScopeGuard fromNonVoidFunction(intFunc);
102 QScopeGuard fromNoDiscardFunction(noDiscardFunc);
103 QScopeGuard fromStdFunction{std::function<void()>(func)};
104 std::function<void()> stdFunction(func);
105 QScopeGuard fromNamedStdFunction(stdFunction);
106#else
107 QSKIP("This test requires C++17 Class Template Argument Deduction support enabled in the compiler.");
108#endif
109}
110
111void tst_QScopeGuard::constructionFromLvalue()
112{
113#ifdef __cpp_deduction_guides
114 Callable::resetCounts();
115 {
116 Callable callable;
117 QScopeGuard guard(callable);
118 }
119 QCOMPARE(Callable::copied, 1);
120 QCOMPARE(Callable::moved, 0);
121 Callable::resetCounts();
122 {
123 Callable callable;
124 auto guard = qScopeGuard(f&: callable);
125 }
126 QCOMPARE(Callable::copied, 1);
127 QCOMPARE(Callable::moved, 0);
128#else
129 QSKIP("This test requires C++17 Class Template Argument Deduction support enabled in the compiler.");
130#endif
131}
132
133void tst_QScopeGuard::constructionFromRvalue()
134{
135#ifdef __cpp_deduction_guides
136 Callable::resetCounts();
137 {
138 Callable callable;
139 QScopeGuard guard(std::move(callable));
140 }
141 QCOMPARE(Callable::copied, 0);
142 QCOMPARE(Callable::moved, 1);
143 Callable::resetCounts();
144 {
145 Callable callable;
146 auto guard = qScopeGuard(f: std::move(callable));
147 }
148 QCOMPARE(Callable::copied, 0);
149 QCOMPARE(Callable::moved, 1);
150#else
151 QSKIP("This test requires C++17 Class Template Argument Deduction support enabled in the compiler.");
152#endif
153}
154
155void tst_QScopeGuard::leavingScope()
156{
157 auto cleanup = qScopeGuard(f: [] { s_globalState++; QCOMPARE(s_globalState, 3); });
158 QCOMPARE(s_globalState, 0);
159
160 {
161 auto cleanup = qScopeGuard(f: [] { s_globalState++; });
162 QCOMPARE(s_globalState, 0);
163 }
164
165 QCOMPARE(s_globalState, 1);
166 s_globalState++;
167}
168
169void tst_QScopeGuard::exceptions()
170{
171 s_globalState = 0;
172 bool caught = false;
173 QT_TRY
174 {
175 auto cleanup = qScopeGuard(f: [] { s_globalState++; });
176 QT_THROW(std::bad_alloc()); //if Qt compiled without exceptions this is noop
177 s_globalState = 100;
178 }
179 QT_CATCH(...)
180 {
181 caught = true;
182 QCOMPARE(s_globalState, 1);
183 }
184
185 QVERIFY((caught && s_globalState == 1) || (!caught && s_globalState == 101));
186
187}
188
189QTEST_MAIN(tst_QScopeGuard)
190#include "tst_qscopeguard.moc"
191

source code of qtbase/tests/auto/corelib/tools/qscopeguard/tst_qscopeguard.cpp