Rework newly-added relational operators

Do not export the hidden friend operator==().
Instead create a helper comparesEqual() hidden friend function and
export it.
This prepares for use of the comparison helper macros.

As a drive-by: move the relational operators to the private section.

Found in 6.7 API review.

Pick-to: 6.7
Change-Id: Id1a813f08bacdcf36417442f0a95774b0a9f7bdb
Reviewed-by: Marc Mutz <marc.mutz@qt.io>

26 files changed, 134 insertions, 73 deletions

diff --git a/src/opcua/client/qopcuaattributeoperand.cpp b/src/opcua/client/qopcuaattributeoperand.cpp
index c253d81..9760246 100644
--- a/src/opcua/client/qopcuaattributeoperand.cpp
+++ b/src/opcua/client/qopcuaattributeoperand.cpp
@@ -162,7 +162,7 @@ void QOpcUaAttributeOperand::setNodeId(const QString &nodeId)
 
     Returns \c true if \a lhs has the same value as \a rhs.
 */
-bool operator==(const QOpcUaAttributeOperand &lhs, const QOpcUaAttributeOperand &rhs) noexcept
+bool comparesEqual(const QOpcUaAttributeOperand &lhs, const QOpcUaAttributeOperand &rhs) noexcept
 {
     return lhs.nodeId() == rhs.nodeId() && lhs.attributeId() == rhs.attributeId() &&
            lhs.alias() == rhs.alias() && lhs.browsePath() == rhs.browsePath() &&
diff --git a/src/opcua/client/qopcuaattributeoperand.h b/src/opcua/client/qopcuaattributeoperand.h
index 73963de..54f822a 100644
--- a/src/opcua/client/qopcuaattributeoperand.h
+++ b/src/opcua/client/qopcuaattributeoperand.h
@@ -43,13 +43,18 @@ public:
     QString indexRange() const;
     void setIndexRange(const QString &indexRange);
 
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaAttributeOperand &lhs, const QOpcUaAttributeOperand &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaAttributeOperand &lhs, const QOpcUaAttributeOperand &rhs) noexcept
+private:
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaAttributeOperand &lhs,
+                                             const QOpcUaAttributeOperand &rhs) noexcept;
+    friend bool operator==(const QOpcUaAttributeOperand &lhs,
+                           const QOpcUaAttributeOperand &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaAttributeOperand &lhs,
+                           const QOpcUaAttributeOperand &rhs) noexcept
     {
         return !(lhs == rhs);
     }
 
-private:
     QSharedDataPointer<QOpcUaAttributeOperandData> data;
 };
 
diff --git a/src/opcua/client/qopcuadatavalue.cpp b/src/opcua/client/qopcuadatavalue.cpp
index 879411a..5c2ae20 100644
--- a/src/opcua/client/qopcuadatavalue.cpp
+++ b/src/opcua/client/qopcuadatavalue.cpp
@@ -199,7 +199,7 @@ void QOpcUaDataValue::setServerPicoseconds(quint16 serverPicoseconds)
 
     Returns \c true if \a lhs is equal to \a rhs.
 */
-bool operator==(const QOpcUaDataValue &lhs, const QOpcUaDataValue &rhs) noexcept
+bool comparesEqual(const QOpcUaDataValue &lhs, const QOpcUaDataValue &rhs) noexcept
 {
     return lhs.data->serverTimestamp == rhs.data->serverTimestamp &&
            lhs.data->serverPicoseconds == rhs.data->serverPicoseconds &&
diff --git a/src/opcua/client/qopcuadatavalue.h b/src/opcua/client/qopcuadatavalue.h
index f382e1c..6df85dc 100644
--- a/src/opcua/client/qopcuadatavalue.h
+++ b/src/opcua/client/qopcuadatavalue.h
@@ -17,11 +17,6 @@ public:
     QOpcUaDataValue();
     QOpcUaDataValue(const QOpcUaDataValue &other);
     QOpcUaDataValue &operator=(const QOpcUaDataValue &other);
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaDataValue &lhs, const QOpcUaDataValue &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaDataValue &lhs, const QOpcUaDataValue &rhs) noexcept
-    {
-        return !(lhs == rhs);
-    }
     ~QOpcUaDataValue();
 
     void swap(QOpcUaDataValue &other) noexcept
@@ -49,6 +44,15 @@ public:
 
 private:
     QExplicitlySharedDataPointer<QOpcUaDataValueData> data;
+
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaDataValue &lhs,
+                                             const QOpcUaDataValue &rhs) noexcept;
+    friend bool operator==(const QOpcUaDataValue &lhs, const QOpcUaDataValue &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaDataValue &lhs, const QOpcUaDataValue &rhs) noexcept
+    {
+        return !(lhs == rhs);
+    }
 };
 
 Q_DECLARE_SHARED(QOpcUaDataValue)
diff --git a/src/opcua/client/qopcuadiagnosticinfo.cpp b/src/opcua/client/qopcuadiagnosticinfo.cpp
index bb0bd41..174c720 100644
--- a/src/opcua/client/qopcuadiagnosticinfo.cpp
+++ b/src/opcua/client/qopcuadiagnosticinfo.cpp
@@ -113,7 +113,7 @@ QOpcUaDiagnosticInfo &QOpcUaDiagnosticInfo::operator=(const QOpcUaDiagnosticInfo
 
     Returns \c true if \a lhs is equal to \a rhs.
 */
-bool operator==(const QOpcUaDiagnosticInfo &lhs, const QOpcUaDiagnosticInfo &rhs) noexcept
+bool comparesEqual(const QOpcUaDiagnosticInfo &lhs, const QOpcUaDiagnosticInfo &rhs) noexcept
 {
     if (lhs.hasSymbolicId() != rhs.hasSymbolicId() ||
         (lhs.hasSymbolicId() && lhs.symbolicId() != rhs.symbolicId()))
diff --git a/src/opcua/client/qopcuadiagnosticinfo.h b/src/opcua/client/qopcuadiagnosticinfo.h
index 46c885c..e0b913c 100644
--- a/src/opcua/client/qopcuadiagnosticinfo.h
+++ b/src/opcua/client/qopcuadiagnosticinfo.h
@@ -26,11 +26,6 @@ public:
     { data.swap(other.data); }
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QOpcUaDiagnosticInfo)
 
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaDiagnosticInfo &lhs, const QOpcUaDiagnosticInfo &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaDiagnosticInfo &lhs, const QOpcUaDiagnosticInfo &rhs) noexcept
-    {
-        return !(lhs == rhs);
-    }
     Q_OPCUA_EXPORT operator QVariant() const;
 
     Q_OPCUA_EXPORT qint32 symbolicId() const;
@@ -78,6 +73,17 @@ public:
 
 private:
     QExplicitlySharedDataPointer<QOpcUaDiagnosticInfoData> data;
+
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaDiagnosticInfo &lhs,
+                                             const QOpcUaDiagnosticInfo &rhs) noexcept;
+    friend bool operator==(const QOpcUaDiagnosticInfo &lhs,
+                           const QOpcUaDiagnosticInfo &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaDiagnosticInfo &lhs,
+                           const QOpcUaDiagnosticInfo &rhs) noexcept
+    {
+        return !(lhs == rhs);
+    }
 };
 
 Q_DECLARE_SHARED(QOpcUaDiagnosticInfo)
diff --git a/src/opcua/client/qopcuaelementoperand.cpp b/src/opcua/client/qopcuaelementoperand.cpp
index 3d10c57..319bfdd 100644
--- a/src/opcua/client/qopcuaelementoperand.cpp
+++ b/src/opcua/client/qopcuaelementoperand.cpp
@@ -114,7 +114,7 @@ void QOpcUaElementOperand::setIndex(quint32 index)
 
     Returns \c true if \a lhs has the same value as \a rhs.
 */
-bool operator==(const QOpcUaElementOperand &lhs, const QOpcUaElementOperand &rhs) noexcept
+bool comparesEqual(const QOpcUaElementOperand &lhs, const QOpcUaElementOperand &rhs) noexcept
 {
     return lhs.index() == rhs.index();
 }
diff --git a/src/opcua/client/qopcuaelementoperand.h b/src/opcua/client/qopcuaelementoperand.h
index ec909dd..4545d3f 100644
--- a/src/opcua/client/qopcuaelementoperand.h
+++ b/src/opcua/client/qopcuaelementoperand.h
@@ -26,13 +26,18 @@ public:
     quint32 index() const;
     void setIndex(quint32 index);
 
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaElementOperand &lhs, const QOpcUaElementOperand &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaElementOperand &lhs, const QOpcUaElementOperand &rhs) noexcept
+private:
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaElementOperand &lhs,
+                                             const QOpcUaElementOperand &rhs) noexcept;
+    friend bool operator==(const QOpcUaElementOperand &lhs,
+                           const QOpcUaElementOperand &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaElementOperand &lhs,
+                           const QOpcUaElementOperand &rhs) noexcept
     {
         return !(lhs == rhs);
     }
 
-private:
     QSharedDataPointer<QOpcUaElementOperandData> data;
 };
 
diff --git a/src/opcua/client/qopcuaenumdefinition.cpp b/src/opcua/client/qopcuaenumdefinition.cpp
index fd90971..a602d5d 100644
--- a/src/opcua/client/qopcuaenumdefinition.cpp
+++ b/src/opcua/client/qopcuaenumdefinition.cpp
@@ -92,7 +92,7 @@ QOpcUaEnumDefinition &QOpcUaEnumDefinition::operator=(const QOpcUaEnumDefinition
 
     Returns \c true if \a lhs is equal to \a rhs.
 */
-bool operator==(const QOpcUaEnumDefinition &lhs, const QOpcUaEnumDefinition &rhs) noexcept
+bool comparesEqual(const QOpcUaEnumDefinition &lhs, const QOpcUaEnumDefinition &rhs) noexcept
 {
     return lhs.data->fields == rhs.fields();
 }
diff --git a/src/opcua/client/qopcuaenumdefinition.h b/src/opcua/client/qopcuaenumdefinition.h
index a76b757..5459078 100644
--- a/src/opcua/client/qopcuaenumdefinition.h
+++ b/src/opcua/client/qopcuaenumdefinition.h
@@ -26,11 +26,6 @@ public:
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QOpcUaEnumDefinition)
     QOpcUaEnumDefinition(QOpcUaEnumDefinition &&other) noexcept = default;
     Q_OPCUA_EXPORT QOpcUaEnumDefinition &operator=(const QOpcUaEnumDefinition &rhs);
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaEnumDefinition &lhs, const QOpcUaEnumDefinition &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaEnumDefinition &lhs, const QOpcUaEnumDefinition &rhs) noexcept
-    {
-        return !(lhs == rhs);
-    }
     Q_OPCUA_EXPORT operator QVariant() const;
     Q_OPCUA_EXPORT ~QOpcUaEnumDefinition();
 
@@ -39,6 +34,16 @@ public:
 
 private:
     QExplicitlySharedDataPointer<QOpcUaEnumDefinitionData> data;
+
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaEnumDefinition &lhs,
+                                             const QOpcUaEnumDefinition &rhs) noexcept;
+    friend bool operator==(const QOpcUaEnumDefinition &lhs,
+                           const QOpcUaEnumDefinition &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend inline bool operator!=(const QOpcUaEnumDefinition &lhs, const QOpcUaEnumDefinition &rhs) noexcept
+    {
+        return !(lhs == rhs);
+    }
 };
 
 Q_DECLARE_SHARED(QOpcUaEnumDefinition)
diff --git a/src/opcua/client/qopcuaenumfield.cpp b/src/opcua/client/qopcuaenumfield.cpp
index 48b9371..8a5ce28 100644
--- a/src/opcua/client/qopcuaenumfield.cpp
+++ b/src/opcua/client/qopcuaenumfield.cpp
@@ -94,7 +94,7 @@ QOpcUaEnumField &QOpcUaEnumField::operator=(const QOpcUaEnumField &rhs)
 
     Returns \c true if \a lhs is equal to \a rhs.
 */
-bool operator==(const QOpcUaEnumField &lhs, const QOpcUaEnumField &rhs) noexcept
+bool comparesEqual(const QOpcUaEnumField &lhs, const QOpcUaEnumField &rhs) noexcept
 {
     return lhs.data->name == rhs.name();
 }
diff --git a/src/opcua/client/qopcuaenumfield.h b/src/opcua/client/qopcuaenumfield.h
index 7ad39db..b38d2fa 100644
--- a/src/opcua/client/qopcuaenumfield.h
+++ b/src/opcua/client/qopcuaenumfield.h
@@ -28,11 +28,6 @@ public:
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QOpcUaEnumField)
     QOpcUaEnumField(QOpcUaEnumField &&other) noexcept = default;
     Q_OPCUA_EXPORT QOpcUaEnumField &operator=(const QOpcUaEnumField &rhs);
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaEnumField &lhs, const QOpcUaEnumField &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaEnumField &lhs, const QOpcUaEnumField &rhs) noexcept
-    {
-        return !(lhs == rhs);
-    }
     Q_OPCUA_EXPORT operator QVariant() const;
     Q_OPCUA_EXPORT ~QOpcUaEnumField();
 
@@ -51,6 +46,15 @@ public:
 
 private:
     QExplicitlySharedDataPointer<QOpcUaEnumFieldData> data;
+
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaEnumField &lhs,
+                                             const QOpcUaEnumField &rhs) noexcept;
+    friend bool operator==(const QOpcUaEnumField &lhs, const QOpcUaEnumField &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaEnumField &lhs, const QOpcUaEnumField &rhs) noexcept
+    {
+        return !(lhs == rhs);
+    }
 };
 
 Q_DECLARE_SHARED(QOpcUaEnumField)
diff --git a/src/opcua/client/qopcuagenericstructvalue.cpp b/src/opcua/client/qopcuagenericstructvalue.cpp
index 79107e2..f596c99 100644
--- a/src/opcua/client/qopcuagenericstructvalue.cpp
+++ b/src/opcua/client/qopcuagenericstructvalue.cpp
@@ -155,7 +155,7 @@ QOpcUaGenericStructValue &QOpcUaGenericStructValue::operator=(const QOpcUaGeneri
 
     Returns \c true if \a lhs is equal to \a rhs.
 */
-bool operator==(const QOpcUaGenericStructValue &lhs, const QOpcUaGenericStructValue &rhs) noexcept
+bool comparesEqual(const QOpcUaGenericStructValue &lhs, const QOpcUaGenericStructValue &rhs) noexcept
 {
     return lhs.typeName() == rhs.typeName() && lhs.typeId() == rhs.typeId() &&
             lhs.structureDefinition() == rhs.structureDefinition() && lhs.fields() == rhs.fields();
diff --git a/src/opcua/client/qopcuagenericstructvalue.h b/src/opcua/client/qopcuagenericstructvalue.h
index 56863bf..7447119 100644
--- a/src/opcua/client/qopcuagenericstructvalue.h
+++ b/src/opcua/client/qopcuagenericstructvalue.h
@@ -34,11 +34,6 @@ public:
     { data.swap(other.data); }
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QOpcUaGenericStructValue)
 
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaGenericStructValue &lhs, const QOpcUaGenericStructValue &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaGenericStructValue &lhs, const QOpcUaGenericStructValue &rhs) noexcept
-    {
-        return !(lhs == rhs);
-    }
     Q_OPCUA_EXPORT operator QVariant() const;
 
     Q_OPCUA_EXPORT QString typeName() const;
@@ -62,6 +57,17 @@ public:
 
 private:
     QExplicitlySharedDataPointer<QOpcUaGenericStructValueData> data;
+
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaGenericStructValue &lhs,
+                                             const QOpcUaGenericStructValue &rhs) noexcept;
+    friend bool operator==(const QOpcUaGenericStructValue &lhs,
+                           const QOpcUaGenericStructValue &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaGenericStructValue &lhs,
+                           const QOpcUaGenericStructValue &rhs) noexcept
+    {
+        return !(lhs == rhs);
+    }
 };
 
 Q_DECLARE_SHARED(QOpcUaGenericStructValue)
diff --git a/src/opcua/client/qopcuahistoryevent.cpp b/src/opcua/client/qopcuahistoryevent.cpp
index 7bca9f5..f605219 100644
--- a/src/opcua/client/qopcuahistoryevent.cpp
+++ b/src/opcua/client/qopcuahistoryevent.cpp
@@ -175,7 +175,7 @@ QOpcUaHistoryEvent &QOpcUaHistoryEvent::operator=(const QOpcUaHistoryEvent &othe
 
     Returns \c true if \a rhs and \a lhs contain the same values.
 */
-bool operator==(const QOpcUaHistoryEvent &lhs, const QOpcUaHistoryEvent &rhs) noexcept
+bool comparesEqual(const QOpcUaHistoryEvent &lhs, const QOpcUaHistoryEvent &rhs) noexcept
 {
     return lhs.events() == rhs.events() && lhs.statusCode() == rhs.statusCode() && lhs.nodeId() == rhs.nodeId();
 }
diff --git a/src/opcua/client/qopcuahistoryevent.h b/src/opcua/client/qopcuahistoryevent.h
index 9be2186..1060972 100644
--- a/src/opcua/client/qopcuahistoryevent.h
+++ b/src/opcua/client/qopcuahistoryevent.h
@@ -38,13 +38,16 @@ public:
     Q_OPCUA_EXPORT QString nodeId() const;
     Q_OPCUA_EXPORT void setNodeId(const QString &nodeId);
 
-
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaHistoryEvent &lhs, const QOpcUaHistoryEvent &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaHistoryEvent &lhs, const QOpcUaHistoryEvent &rhs) noexcept
+private:
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaHistoryEvent &lhs,
+                                             const QOpcUaHistoryEvent &rhs) noexcept;
+    friend bool operator==(const QOpcUaHistoryEvent &lhs, const QOpcUaHistoryEvent &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaHistoryEvent &lhs, const QOpcUaHistoryEvent &rhs) noexcept
     {
         return !(lhs == rhs);
     }
-private:
+
     QExplicitlySharedDataPointer<QOpcUaHistoryEventData> data;
 };
 
diff --git a/src/opcua/client/qopcuahistoryreadeventrequest.cpp b/src/opcua/client/qopcuahistoryreadeventrequest.cpp
index 5d7e02b..96d7726 100644
--- a/src/opcua/client/qopcuahistoryreadeventrequest.cpp
+++ b/src/opcua/client/qopcuahistoryreadeventrequest.cpp
@@ -228,8 +228,8 @@ QOpcUaHistoryReadEventRequest &QOpcUaHistoryReadEventRequest::operator=(const QO
     Two QOpcUaHistoryReadEventRequest items are considered equal if their \c startTimestamp,
     \c endTimestamp, \c numValuesPerNode, \c filter and \c nodesToRead are equal.
 */
-bool operator==(const QOpcUaHistoryReadEventRequest &lhs,
-                const QOpcUaHistoryReadEventRequest &rhs) noexcept
+bool comparesEqual(const QOpcUaHistoryReadEventRequest &lhs,
+                   const QOpcUaHistoryReadEventRequest &rhs) noexcept
 {
     return (lhs.data->startTimestamp == rhs.data->startTimestamp &&
             lhs.data->endTimestamp == rhs.data->endTimestamp &&
diff --git a/src/opcua/client/qopcuahistoryreadeventrequest.h b/src/opcua/client/qopcuahistoryreadeventrequest.h
index 32fdde0..48ddb88 100644
--- a/src/opcua/client/qopcuahistoryreadeventrequest.h
+++ b/src/opcua/client/qopcuahistoryreadeventrequest.h
@@ -55,15 +55,18 @@ public:
 
     Q_OPCUA_EXPORT void addNodeToRead(const QOpcUaReadItem &nodeToRead);
 
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaHistoryReadEventRequest &lhs,
-                                                         const QOpcUaHistoryReadEventRequest &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaHistoryReadEventRequest &lhs,
-                                  const QOpcUaHistoryReadEventRequest &rhs) noexcept
+private:
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaHistoryReadEventRequest &lhs,
+                                             const QOpcUaHistoryReadEventRequest &rhs) noexcept;
+    friend bool operator==(const QOpcUaHistoryReadEventRequest &lhs,
+                           const QOpcUaHistoryReadEventRequest &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaHistoryReadEventRequest &lhs,
+                           const QOpcUaHistoryReadEventRequest &rhs) noexcept
     {
         return !(lhs == rhs);
     }
 
-private:
     QExplicitlySharedDataPointer<QOpcUaHistoryReadEventRequestData> data;
 };
 
diff --git a/src/opcua/client/qopcualiteraloperand.cpp b/src/opcua/client/qopcualiteraloperand.cpp
index e96f69f..3bab744 100644
--- a/src/opcua/client/qopcualiteraloperand.cpp
+++ b/src/opcua/client/qopcualiteraloperand.cpp
@@ -109,7 +109,7 @@ void QOpcUaLiteralOperand::setValue(const QVariant &value)
 
     Returns \c true if \a lhs has the same value as \a rhs.
 */
-bool operator==(const QOpcUaLiteralOperand &lhs, const QOpcUaLiteralOperand &rhs) noexcept
+bool comparesEqual(const QOpcUaLiteralOperand &lhs, const QOpcUaLiteralOperand &rhs) noexcept
 {
     return lhs.value() == rhs.value() && lhs.type() == rhs.type();
 }
diff --git a/src/opcua/client/qopcualiteraloperand.h b/src/opcua/client/qopcualiteraloperand.h
index 09cadf5..f6978ad 100644
--- a/src/opcua/client/qopcualiteraloperand.h
+++ b/src/opcua/client/qopcualiteraloperand.h
@@ -28,14 +28,18 @@ public:
     QOpcUa::Types type() const;
     void setType(QOpcUa::Types type);
 
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaLiteralOperand &lhs, const QOpcUaLiteralOperand &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaLiteralOperand &lhs, const QOpcUaLiteralOperand &rhs) noexcept
+private:
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaLiteralOperand &lhs,
+                                             const QOpcUaLiteralOperand &rhs) noexcept;
+    friend bool operator==(const QOpcUaLiteralOperand &lhs,
+                           const QOpcUaLiteralOperand &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaLiteralOperand &lhs,
+                           const QOpcUaLiteralOperand &rhs) noexcept
     {
         return !(lhs == rhs);
     }
 
-
-private:
     QSharedDataPointer<QOpcUaLiteralOperandData> data;
 };
 
diff --git a/src/opcua/client/qopcuastructuredefinition.cpp b/src/opcua/client/qopcuastructuredefinition.cpp
index c5691b7..395d35b 100644
--- a/src/opcua/client/qopcuastructuredefinition.cpp
+++ b/src/opcua/client/qopcuastructuredefinition.cpp
@@ -95,7 +95,7 @@ QOpcUaStructureDefinition &QOpcUaStructureDefinition::operator=(const QOpcUaStru
 
     Returns \c true if \a lhs is equal to \a rhs.
 */
-bool operator==(const QOpcUaStructureDefinition &lhs, const QOpcUaStructureDefinition &rhs) noexcept
+bool comparesEqual(const QOpcUaStructureDefinition &lhs, const QOpcUaStructureDefinition &rhs) noexcept
 {
     return lhs.data->defaultEncodingId == rhs.defaultEncodingId() &&
             lhs.data->baseDataType == rhs.baseDataType() &&
diff --git a/src/opcua/client/qopcuastructuredefinition.h b/src/opcua/client/qopcuastructuredefinition.h
index f4c94df..911317c 100644
--- a/src/opcua/client/qopcuastructuredefinition.h
+++ b/src/opcua/client/qopcuastructuredefinition.h
@@ -27,11 +27,6 @@ public:
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QOpcUaStructureDefinition)
     QOpcUaStructureDefinition(QOpcUaStructureDefinition &&other) noexcept = default;
     Q_OPCUA_EXPORT QOpcUaStructureDefinition &operator=(const QOpcUaStructureDefinition &);
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaStructureDefinition &lhs, const QOpcUaStructureDefinition &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaStructureDefinition &lhs, const QOpcUaStructureDefinition &rhs) noexcept
-    {
-        return !(lhs == rhs);
-    }
     Q_OPCUA_EXPORT operator QVariant() const;
     Q_OPCUA_EXPORT ~QOpcUaStructureDefinition();
 
@@ -55,6 +50,17 @@ public:
 
 private:
     QExplicitlySharedDataPointer<QOpcUaStructureDefinitionData> data;
+
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaStructureDefinition &lhs,
+                                             const QOpcUaStructureDefinition &rhs) noexcept;
+    friend bool operator==(const QOpcUaStructureDefinition &lhs,
+                           const QOpcUaStructureDefinition &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaStructureDefinition &lhs,
+                           const QOpcUaStructureDefinition &rhs) noexcept
+    {
+        return !(lhs == rhs);
+    }
 };
 
 Q_DECLARE_SHARED(QOpcUaStructureDefinition)
diff --git a/src/opcua/client/qopcuastructurefield.cpp b/src/opcua/client/qopcuastructurefield.cpp
index 41993d2..2491ca2 100644
--- a/src/opcua/client/qopcuastructurefield.cpp
+++ b/src/opcua/client/qopcuastructurefield.cpp
@@ -98,7 +98,7 @@ QOpcUaStructureField &QOpcUaStructureField::operator=(const QOpcUaStructureField
 
     Returns \c true \a lhs is equal to \a rhs.
 */
-bool operator==(const QOpcUaStructureField &lhs, const QOpcUaStructureField &rhs) noexcept
+bool comparesEqual(const QOpcUaStructureField &lhs, const QOpcUaStructureField &rhs) noexcept
 {
     return lhs.data->name == rhs.name() &&
            lhs.data->description == rhs.description() &&
diff --git a/src/opcua/client/qopcuastructurefield.h b/src/opcua/client/qopcuastructurefield.h
index 556af76..fcab68a 100644
--- a/src/opcua/client/qopcuastructurefield.h
+++ b/src/opcua/client/qopcuastructurefield.h
@@ -27,11 +27,6 @@ public:
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QOpcUaStructureField)
     QOpcUaStructureField(QOpcUaStructureField &&other) noexcept = default;
     Q_OPCUA_EXPORT QOpcUaStructureField &operator=(const QOpcUaStructureField &rhs);
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaStructureField &lhs, const QOpcUaStructureField &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaStructureField &lhs, const QOpcUaStructureField &rhs) noexcept
-    {
-        return !(lhs == rhs);
-    }
     Q_OPCUA_EXPORT operator QVariant() const;
     Q_OPCUA_EXPORT ~QOpcUaStructureField();
 
@@ -58,6 +53,17 @@ public:
 
 private:
     QExplicitlySharedDataPointer<QOpcUaStructureFieldData> data;
+
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaStructureField &lhs,
+                                             const QOpcUaStructureField &rhs) noexcept;
+    friend bool operator==(const QOpcUaStructureField &lhs,
+                           const QOpcUaStructureField &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend inline bool operator!=(const QOpcUaStructureField &lhs,
+                                  const QOpcUaStructureField &rhs) noexcept
+    {
+        return !(lhs == rhs);
+    }
 };
 
 Q_DECLARE_SHARED(QOpcUaStructureField)
diff --git a/src/opcua/client/qopcuavariant.cpp b/src/opcua/client/qopcuavariant.cpp
index 7e894c8..c2c1cb1 100644
--- a/src/opcua/client/qopcuavariant.cpp
+++ b/src/opcua/client/qopcuavariant.cpp
@@ -146,7 +146,7 @@ QOpcUaVariant &QOpcUaVariant::operator=(const QOpcUaVariant &rhs)
 }
 
 
-bool operator==(const QOpcUaVariant &lhs, const QOpcUaVariant &rhs) noexcept
+bool comparesEqual(const QOpcUaVariant &lhs, const QOpcUaVariant &rhs) noexcept
 {
     return lhs.data->value == rhs.data->value &&
            lhs.data->valueType == rhs.data->valueType &&
diff --git a/src/opcua/client/qopcuavariant.h b/src/opcua/client/qopcuavariant.h
index da16339..39a55a6 100644
--- a/src/opcua/client/qopcuavariant.h
+++ b/src/opcua/client/qopcuavariant.h
@@ -59,11 +59,6 @@ public:
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QOpcUaVariant)
     QOpcUaVariant(QOpcUaVariant &&other) noexcept = default;
     Q_OPCUA_EXPORT QOpcUaVariant &operator=(const QOpcUaVariant &rhs);
-    friend Q_OPCUA_EXPORT bool operator==(const QOpcUaVariant &lhs, const QOpcUaVariant &rhs) noexcept;
-    friend inline bool operator!=(const QOpcUaVariant &lhs, const QOpcUaVariant &rhs) noexcept
-    {
-        return !(lhs == rhs);
-    }
 
     Q_OPCUA_EXPORT QVariant value() const;
     Q_OPCUA_EXPORT void setValue(ValueType type, const QVariant &value, bool isArray = false,
@@ -77,6 +72,15 @@ public:
 
 private:
     QExplicitlySharedDataPointer<QOpcUaVariantData> data;
+
+    friend Q_OPCUA_EXPORT bool comparesEqual(const QOpcUaVariant &lhs,
+                                             const QOpcUaVariant &rhs) noexcept;
+    friend bool operator==(const QOpcUaVariant &lhs, const QOpcUaVariant &rhs) noexcept
+    { return comparesEqual(lhs, rhs); }
+    friend bool operator!=(const QOpcUaVariant &lhs, const QOpcUaVariant &rhs) noexcept
+    {
+        return !(lhs == rhs);
+    }
 };
 
 Q_DECLARE_SHARED(QOpcUaVariant)