Since C++20 we no longer need operator!=.

src/app/puzzle/layout/layoutdef.cpp

@@ -89,8 +89,10 @@ auto VPTransformationOrigon::operator==(const VPTransformationOrigon &origin) co
     return this->origin == origin.origin && custom == origin.custom;
 }
 
+#if __cplusplus < 202002L
 //---------------------------------------------------------------------------------------------------------------------
 auto VPTransformationOrigon::operator!=(const VPTransformationOrigon &origin) const -> bool
 {
     return !VPTransformationOrigon::operator==(origin);
 }
+#endif

src/app/puzzle/layout/layoutdef.h

@@ -59,7 +59,10 @@ struct VPTransformationOrigon
     bool custom{false}; // NOLINT(misc-non-private-member-variables-in-classes)
 
     auto operator==(const VPTransformationOrigon &origin) const -> bool;
+
+#if __cplusplus < 202002L
     auto operator!=(const VPTransformationOrigon &origin) const -> bool;
+#endif
 };
 
 #endif // LAYOUTDEF_H

src/libs/vpatterndb/vformula.cpp

@@ -87,11 +87,13 @@ auto VFormula::operator==(const VFormula &formula) const -> bool
            d->error == formula.error() && VFuzzyComparePossibleNulls(d->dValue, formula.getDoubleValue());
 }
 
+#if __cplusplus < 202002L
 //---------------------------------------------------------------------------------------------------------------------
 auto VFormula::operator!=(const VFormula &formula) const -> bool
 {
     return !VFormula::operator==(formula);
 }
+#endif
 
 //---------------------------------------------------------------------------------------------------------------------
 auto VFormula::GetFormula(FormulaType type) const -> QString

src/libs/vpatterndb/vformula.h

@@ -59,7 +59,10 @@ public:
     ~VFormula();
 
     auto operator==(const VFormula &formula) const -> bool;
+
+#if __cplusplus < 202002L
     auto operator!=(const VFormula &formula) const -> bool;
+#endif
 
     auto GetFormula(FormulaType type = FormulaType::ToUser) const -> QString;
     void SetFormula(const QString &value, FormulaType type = FormulaType::FromSystem);