QMessageAuthenticationCode: add move SMFs and swap()

QCryptographicHash is move-only these days, so
QMessageAuthenticationCode should not be left behind.

[ChangeLog][QtCore][QMessageAuthenticationCode] Added move
constructor, move assignment operator and swap() function.

Fixes: QTBUG-111677
Change-Id: I420f24c04828e8ad7043a9e8c9e7e2d47dd183e0
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

src/corelib/tools/qcryptographichash.cpp

@@ -1262,6 +1262,39 @@ QMessageAuthenticationCode::~QMessageAuthenticationCode()
     delete d;
 }
 
+/*!
+    \fn QMessageAuthenticationCode::QMessageAuthenticationCode(QMessageAuthenticationCode &&other)
+
+    Move-constructs a new QMessageAuthenticationCode from \a other.
+
+    \note The moved-from object \a other is placed in a
+    partially-formed state, in which the only valid operations are
+    destruction and assignment of a new object.
+
+    \since 6.6
+*/
+
+/*!
+    \fn QMessageAuthenticationCode &QMessageAuthenticationCode::operator=(QMessageAuthenticationCode &&other)
+
+    Move-assigns \a other to this QMessageAuthenticationCode instance.
+
+    \note The moved-from object \a other is placed in a
+    partially-formed state, in which the only valid operations are
+    destruction and assignment of a new object.
+
+    \since 6.6
+*/
+
+/*!
+    \fn void QMessageAuthenticationCode::swap(QMessageAuthenticationCode &other)
+
+    Swaps message authentication code \a other with this message authentication
+    code. This operation is very fast and never fails.
+
+    \since 6.6
+*/
+
 /*!
     Resets message data. Calling this method doesn't affect the key.
 */

src/corelib/tools/qmessageauthenticationcode.h

@@ -18,8 +18,14 @@ class Q_CORE_EXPORT QMessageAuthenticationCode
 public:
     explicit QMessageAuthenticationCode(QCryptographicHash::Algorithm method,
                                         const QByteArray &key = QByteArray());
+    QMessageAuthenticationCode(QMessageAuthenticationCode &&other) noexcept
+        : d{std::exchange(other.d, nullptr)} {}
     ~QMessageAuthenticationCode();
 
+    QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_MOVE_AND_SWAP(QMessageAuthenticationCode)
+    void swap(QMessageAuthenticationCode &other) noexcept
+    { qt_ptr_swap(d, other.d); }
+
     void reset();
 
     void setKey(const QByteArray &key);

tests/auto/corelib/tools/qmessageauthenticationcode/tst_qmessageauthenticationcode.cpp

@@ -20,6 +20,8 @@ private slots:
     void result_incremental();
     void addData_overloads_data();
     void addData_overloads();
+    void move();
+    void swap();
 };
 
 Q_DECLARE_METATYPE(QCryptographicHash::Algorithm)
@@ -219,5 +221,48 @@ void tst_QMessageAuthenticationCode::addData_overloads()
     }
 }
 
+void tst_QMessageAuthenticationCode::move()
+{
+    const QByteArray key = "123";
+
+    QMessageAuthenticationCode src(QCryptographicHash::Sha1, key);
+    src.addData("a");
+
+    // move constructor
+    auto intermediary = std::move(src);
+    intermediary.addData("b");
+
+    // move assign operator
+    QMessageAuthenticationCode dst(QCryptographicHash::Sha256, key);
+    dst.addData("no effect on the end result");
+    dst = std::move(intermediary);
+    dst.addData("c");
+
+    QCOMPARE(dst.resultView(),
+             QMessageAuthenticationCode::hash("abc", key, QCryptographicHash::Sha1));
+}
+
+void tst_QMessageAuthenticationCode::swap()
+{
+    const QByteArray key1 = "123";
+    const QByteArray key2 = "abcdefg";
+
+    QMessageAuthenticationCode mac1(QCryptographicHash::Sha1,   key1);
+    QMessageAuthenticationCode mac2(QCryptographicHash::Sha256, key2);
+
+    mac1.addData("da");
+    mac2.addData("te");
+
+    mac1.swap(mac2);
+
+    mac2.addData("ta");
+    mac1.addData("st");
+
+    QCOMPARE(mac2.resultView(),
+             QMessageAuthenticationCode::hash("data", key1, QCryptographicHash::Sha1));
+    QCOMPARE(mac1.resultView(),
+             QMessageAuthenticationCode::hash("test", key2, QCryptographicHash::Sha256));
+}
+
 QTEST_MAIN(tst_QMessageAuthenticationCode)
 #include "tst_qmessageauthenticationcode.moc"