QMimeType: use modernize comparisons

Replace class operators operator==(), operator!=() of
QMimeType to friend method comparesEqual() and
Q_DECLARE_EQUALITY_COMPARABLE macro.

Use QT_CORE_REMOVED_SINCE and removed_api.cpp to get rid of
current comparison methods and replace them with a friend.

Task-number: QTBUG-120304
Change-Id: I9776e98c8a3b14d599733c91af61fbc12b1f0e57
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

src/corelib/compat/removed_api.cpp

@@ -1006,6 +1006,13 @@ bool QJsonValue::operator!=(const QJsonValue &other) const
     return !comparesEqual(*this, other);
 }
 
+#include "qmimetype.h"
+
+bool QMimeType::operator==(const QMimeType &other) const
+{
+    return comparesEqual(*this, other);
+}
+
 #include "qobject.h"
 
 int QObject::startTimer(std::chrono::milliseconds time, Qt::TimerType timerType)

src/corelib/mimetypes/qmimetype.cpp

@@ -24,6 +24,7 @@ using namespace Qt::StringLiterals;
     \brief The QMimeType class describes types of file or data, represented by a MIME type string.
 
     \since 5.0
+    \compares equality
 
     For instance a file named "readme.txt" has the MIME type "text/plain".
     The MIME type can be determined from the file name, or from the file
@@ -111,14 +112,15 @@ QMimeType::~QMimeType()
 }
 
 /*!
-    \fn bool QMimeType::operator==(const QMimeType &other) const;
-    Returns \c true if \a other equals this QMimeType object, otherwise returns \c false.
+    \fn bool QMimeType::operator==(const QMimeType &lhs, const QMimeType &rhs);
+    Returns \c true if \a lhs equals to the \a rhs QMimeType object, otherwise
+    returns \c false.
     The name is the unique identifier for a mimetype, so two mimetypes with
     the same name, are equal.
  */
-bool QMimeType::operator==(const QMimeType &other) const
+bool comparesEqual(const QMimeType &lhs, const QMimeType &rhs) noexcept
 {
-    return d == other.d || d->name == other.d->name;
+    return lhs.d == rhs.d || lhs.d->name == rhs.d->name;
 }
 
 /*!
@@ -134,8 +136,9 @@ size_t qHash(const QMimeType &key, size_t seed) noexcept
 }
 
 /*!
-    \fn bool QMimeType::operator!=(const QMimeType &other) const;
-    Returns \c true if \a other does not equal this QMimeType object, otherwise returns \c false.
+    \fn bool QMimeType::operator!=(const QMimeType &lhs, const QMimeType &rhs);
+    Returns \c true if QMimeType \a lhs is not equal to QMimeType \a rhs,
+    otherwise returns \c false.
  */
 
 /*!

src/corelib/mimetypes/qmimetype.h

@@ -49,14 +49,14 @@ public:
     }
     explicit QMimeType(const QMimeTypePrivate &dd);
     ~QMimeType();
-
+#if QT_CORE_REMOVED_SINCE(6, 8)
     bool operator==(const QMimeType &other) const;
 
     inline bool operator!=(const QMimeType &other) const
     {
         return !operator==(other);
     }
-
+#endif
     bool isValid() const;
 
     bool isDefault() const;
@@ -86,6 +86,10 @@ protected:
     friend Q_CORE_EXPORT size_t qHash(const QMimeType &key, size_t seed) noexcept;
 
     QExplicitlySharedDataPointer<QMimeTypePrivate> d;
+
+private:
+    friend Q_CORE_EXPORT bool comparesEqual(const QMimeType &lhs, const QMimeType &rhs) noexcept;
+    Q_DECLARE_EQUALITY_COMPARABLE(QMimeType)
 };
 
 Q_DECLARE_SHARED(QMimeType)

tests/auto/corelib/mimetypes/qmimetype/CMakeLists.txt

@@ -16,4 +16,5 @@ qt_internal_add_test(tst_qmimetype
         tst_qmimetype.cpp
     LIBRARIES
         Qt::CorePrivate
+        Qt::TestPrivate
 )

tests/auto/corelib/mimetypes/qmimetype/tst_qmimetype.cpp

@@ -8,7 +8,7 @@
 #include <QVariantMap>
 
 #include <QTest>
-
+#include <QtTest/private/qcomparisontesthelper_p.h>
 
 class tst_qmimetype : public QObject
 {
@@ -17,7 +17,9 @@ class tst_qmimetype : public QObject
 private slots:
     void initTestCase();
 
+    void compareCompiles();
     void isValid();
+    void compareQMimetypes();
     void name();
     void genericIconName();
     void iconName();
@@ -41,6 +43,28 @@ static QString qMimeTypeName()
 
 // ------------------------------------------------------------------------------------------------
 
+void tst_qmimetype::compareCompiles()
+{
+    QTestPrivate::testEqualityOperatorsCompile<QMimeType>();
+}
+
+// ------------------------------------------------------------------------------------------------
+
+void tst_qmimetype::compareQMimetypes()
+{
+    QMimeType instantiatedQMimeType{ QMimeTypePrivate(qMimeTypeName()) };
+    QMimeType otherQMimeType (instantiatedQMimeType);
+    QMimeType defaultQMimeType;
+
+    QVERIFY(!defaultQMimeType.isValid());
+    QT_TEST_EQUALITY_OPS(defaultQMimeType, QMimeType(), true);
+    QT_TEST_EQUALITY_OPS(QMimeType(), QMimeType(), true);
+    QT_TEST_EQUALITY_OPS(instantiatedQMimeType, QMimeType(), false);
+    QT_TEST_EQUALITY_OPS(otherQMimeType, defaultQMimeType, false);
+}
+
+// ------------------------------------------------------------------------------------------------
+
 void tst_qmimetype::isValid()
 {
     QMimeType instantiatedQMimeType{ QMimeTypePrivate(qMimeTypeName()) };
@@ -49,7 +73,7 @@ void tst_qmimetype::isValid()
     QMimeType otherQMimeType (instantiatedQMimeType);
 
     QVERIFY(otherQMimeType.isValid());
-    QCOMPARE(instantiatedQMimeType, otherQMimeType);
+    QT_TEST_EQUALITY_OPS(instantiatedQMimeType, otherQMimeType, true);
 
     QMimeType defaultQMimeType;
 
@@ -66,8 +90,7 @@ void tst_qmimetype::name()
     // Verify that the Name is part of the equality test:
     QCOMPARE(instantiatedQMimeType.name(), qMimeTypeName());
 
-    QVERIFY(instantiatedQMimeType != otherQMimeType);
-    QVERIFY(!(instantiatedQMimeType == otherQMimeType));
+    QT_TEST_EQUALITY_OPS(instantiatedQMimeType, otherQMimeType, false);
 }
 
 // ------------------------------------------------------------------------------------------------