Let the compiler generate more comparison operators in WebCore

https://bugs.webkit.org/show_bug.cgi?id=260943

Reviewed by Timothy Hatcher, Ryosuke Niwa and Darin Adler.

Let the compiler generate more comparison operators in WebCore now that we
support C++20.

* Source/WebCore/Modules/highlight/AppHighlightRangeData.h:
(WebCore::AppHighlightRangeData::NodePathComponent::operator== const): Deleted.
* Source/WebCore/Modules/indexeddb/IDBDatabaseIdentifier.h:
(WebCore::IDBDatabaseIdentifier::operator== const): Deleted.
* Source/WebCore/Modules/indexeddb/shared/IDBResourceIdentifier.h:
(WebCore::IDBResourceIdentifier::operator== const): Deleted.
* Source/WebCore/Modules/mediasession/MediaPositionState.h:
(WebCore::MediaPositionState::operator== const): Deleted.
* Source/WebCore/Modules/permissions/PermissionDescriptor.h:
(WebCore::PermissionDescriptor::operator== const): Deleted.
* Source/WebCore/Modules/webaudio/BaseAudioContext.h:
* Source/WebCore/PAL/pal/SessionID.h:
(PAL::SessionID::operator== const): Deleted.
* Source/WebCore/contentextensions/ContentExtensionActions.cpp:
(WebCore::ContentExtensions::ModifyHeadersAction::operator== const): Deleted.
(WebCore::ContentExtensions::ModifyHeadersAction::ModifyHeaderInfo::operator== const): Deleted.
(WebCore::ContentExtensions::RedirectAction::operator== const): Deleted.
(WebCore::ContentExtensions::RedirectAction::URLTransformAction::operator== const): Deleted.
(WebCore::ContentExtensions::RedirectAction::URLTransformAction::QueryTransform::operator== const): Deleted.
(WebCore::ContentExtensions::RedirectAction::URLTransformAction::QueryTransform::QueryKeyValue::operator== const): Deleted.
* Source/WebCore/contentextensions/ContentExtensionActions.h:
(WebCore::ContentExtensions::ActionWithoutMetadata::operator== const): Deleted.
(WebCore::ContentExtensions::ActionWithStringMetadata::operator== const): Deleted.
* Source/WebCore/contentextensions/ContentExtensionRule.h:
(WebCore::ContentExtensions::Trigger::operator== const): Deleted.
(WebCore::ContentExtensions::Action::operator== const): Deleted.
(WebCore::ContentExtensions::ContentExtensionRule::operator== const): Deleted.
* Source/WebCore/contentextensions/NFAToDFA.cpp:
* Source/WebCore/contentextensions/Term.h:
(WebCore::ContentExtensions::Term::CharacterSet::operator== const): Deleted.
(WebCore::ContentExtensions::Term::Group::operator== const): Deleted.
* Source/WebCore/css/CSSCounterStyleDescriptors.h:
(WebCore::CSSCounterStyleDescriptors::operator== const):
(WebCore::CSSCounterStyleDescriptors::Symbol::operator== const): Deleted.
(WebCore::CSSCounterStyleDescriptors::Pad::operator== const): Deleted.
(WebCore::CSSCounterStyleDescriptors::NegativeSymbols::operator== const): Deleted.
* Source/WebCore/css/CSSCounterStyleRegistry.cpp:
(WebCore::CSSCounterStyleRegistry::operator== const):
* Source/WebCore/css/CSSCustomPropertyValue.h:
* Source/WebCore/css/CSSFontFace.h:
* Source/WebCore/css/CSSGradientValue.cpp:
(WebCore::CSSLinearGradientValue::Angle::operator==):
(WebCore::CSSPrefixedLinearGradientValue::operator==):
(WebCore::CSSRadialGradientValue::operator==):
(WebCore::CSSPrefixedRadialGradientValue::operator==):
(WebCore::CSSConicGradientValue::operator==):
* Source/WebCore/css/CSSGradientValue.h:
(WebCore::CSSGradientColorInterpolationMethod::legacyMethod):
(WebCore::operator==):

Canonical link: https://commits.webkit.org/267512@main

Source/WebCore/Modules/highlight/AppHighlightRangeData.h

@@ -61,10 +61,7 @@ WTF_MAKE_FAST_ALLOCATED;
         {
         }
 
-        bool operator==(const NodePathComponent& other) const
-        {
-            return identifier == other.identifier && nodeName == other.nodeName && textData == other.textData && pathIndex == other.pathIndex;
-        }
+        friend bool operator==(const NodePathComponent&, const NodePathComponent&) = default;
     };
 
     using NodePath = Vector<NodePathComponent>;

Source/WebCore/Modules/indexeddb/IDBDatabaseIdentifier.h

@@ -62,10 +62,7 @@ class IDBDatabaseIdentifier {
         return m_databaseName.isNull();
     }
 
-    bool operator==(const IDBDatabaseIdentifier& other) const
-    {
-        return other.m_databaseName == m_databaseName && other.m_origin == m_origin && other.m_isTransient == m_isTransient;
-    }
+    friend bool operator==(const IDBDatabaseIdentifier&, const IDBDatabaseIdentifier&) = default;
 
     const String& databaseName() const { return m_databaseName; }
     const ClientOrigin& origin() const { return m_origin; }

Source/WebCore/Modules/indexeddb/shared/IDBResourceIdentifier.h

@@ -55,11 +55,7 @@ class IDBResourceIdentifier {
         return !m_resourceNumber && !m_idbConnectionIdentifier;
     }
 
-    bool operator==(const IDBResourceIdentifier& other) const
-    {
-        return m_idbConnectionIdentifier == other.m_idbConnectionIdentifier
-            && m_resourceNumber == other.m_resourceNumber;
-    }
+    friend bool operator==(const IDBResourceIdentifier&, const IDBResourceIdentifier&) = default;
 
     IDBConnectionIdentifier connectionIdentifier() const { return m_idbConnectionIdentifier; }
 

Source/WebCore/Modules/mediasession/MediaPositionState.h

@@ -36,7 +36,7 @@ struct MediaPositionState {
 
     String toJSONString() const;
 
-    bool operator==(const MediaPositionState& other) const { return duration == other.duration && playbackRate == other.playbackRate && position == other.position; }
+    friend bool operator==(const MediaPositionState&, const MediaPositionState&) = default;
 };
 
 }

Source/WebCore/Modules/permissions/PermissionDescriptor.h

@@ -33,7 +33,7 @@ namespace WebCore {
 struct PermissionDescriptor {
     PermissionName name;
 
-    bool operator==(const PermissionDescriptor& descriptor) const { return name == descriptor.name; }
+    friend bool operator==(PermissionDescriptor, PermissionDescriptor) = default;
 };
 
 } // namespace WebCore

Source/WebCore/Modules/webaudio/BaseAudioContext.h

@@ -317,7 +317,7 @@ class BaseAudioContext
         TailProcessingNode& operator=(const TailProcessingNode&) = delete;
         TailProcessingNode& operator=(TailProcessingNode&&) = delete;
         AudioNode* operator->() const { return m_node.get(); }
-        bool operator==(const TailProcessingNode& other) const { return m_node == other.m_node; }
+        friend bool operator==(const TailProcessingNode&, const TailProcessingNode&) = default;
         bool operator==(const AudioNode& node) const { return m_node == &node; }
     private:
         RefPtr<AudioNode> m_node;

Source/WebCore/PAL/pal/SessionID.h

@@ -70,7 +70,7 @@ class SessionID {
     bool isHashTableDeletedValue() const { return m_identifier == HashTableDeletedValueID; }
 
     uint64_t toUInt64() const { return m_identifier; }
-    bool operator==(SessionID sessionID) const { return m_identifier == sessionID.m_identifier; }
+    friend bool operator==(SessionID, SessionID) = default;
     bool isAlwaysOnLoggingAllowed() const { return !isEphemeral(); }
 
     template<class Encoder> void encode(Encoder&) const;

Source/WebCore/contentextensions/ContentExtensionActions.cpp

@@ -130,14 +130,6 @@ ModifyHeadersAction ModifyHeadersAction::isolatedCopy() &&
     return { crossThreadCopy(WTFMove(requestHeaders)), crossThreadCopy(WTFMove(responseHeaders)), crossThreadCopy(priority) };
 }
 
-bool ModifyHeadersAction::operator==(const ModifyHeadersAction& other) const
-{
-    return other.hashTableType == this->hashTableType
-        && other.requestHeaders == this->requestHeaders
-        && other.responseHeaders == this->responseHeaders
-        && other.priority == this->priority;
-}
-
 void ModifyHeadersAction::serialize(Vector<uint8_t>& vector) const
 {
     auto beginIndex = vector.size();
@@ -257,11 +249,6 @@ auto ModifyHeadersAction::ModifyHeaderInfo::isolatedCopy() && -> ModifyHeaderInf
     return { crossThreadCopy(WTFMove(operation)) };
 }
 
-bool ModifyHeadersAction::ModifyHeaderInfo::operator==(const ModifyHeaderInfo& other) const
-{
-    return other.operation == this->operation;
-}
-
 void ModifyHeadersAction::ModifyHeaderInfo::serialize(Vector<uint8_t>& vector) const
 {
     auto beginIndex = vector.size();
@@ -352,12 +339,6 @@ RedirectAction RedirectAction::isolatedCopy() &&
     return { crossThreadCopy(WTFMove(action)) };
 }
 
-bool RedirectAction::operator==(const RedirectAction& other) const
-{
-    return other.hashTableType == this->hashTableType
-        && other.action == this->action;
-}
-
 void RedirectAction::serialize(Vector<uint8_t>& vector) const
 {
     auto beginIndex = vector.size();
@@ -559,18 +540,6 @@ auto RedirectAction::URLTransformAction::isolatedCopy() && -> URLTransformAction
         crossThreadCopy(WTFMove(queryTransform)), crossThreadCopy(WTFMove(scheme)), crossThreadCopy(WTFMove(username)) };
 }
 
-bool RedirectAction::URLTransformAction::operator==(const URLTransformAction& other) const
-{
-    return other.fragment == this->fragment
-        && other.host == this->host
-        && other.password == this->password
-        && other.path == this->path
-        && other.port == this->port
-        && other.queryTransform == this->queryTransform
-        && other.scheme == this->scheme
-        && other.username == this->username;
-}
-
 void RedirectAction::URLTransformAction::serialize(Vector<uint8_t>& vector) const
 {
     uint8_t hasFragment = !!fragment;
@@ -853,12 +822,6 @@ auto RedirectAction::URLTransformAction::QueryTransform::isolatedCopy() && -> Qu
     return { crossThreadCopy(WTFMove(addOrReplaceParams)), crossThreadCopy(WTFMove(removeParams)) };
 }
 
-bool RedirectAction::URLTransformAction::QueryTransform::operator==(const QueryTransform& other) const
-{
-    return other.addOrReplaceParams == this->addOrReplaceParams
-        && other.removeParams == this->removeParams;
-}
-
 void RedirectAction::URLTransformAction::QueryTransform::serialize(Vector<uint8_t>& vector) const
 {
     auto beginIndex = vector.size();
@@ -925,13 +888,6 @@ auto RedirectAction::URLTransformAction::QueryTransform::QueryKeyValue::parse(co
     return { { WTFMove(key), replaceOnly, WTFMove(value) } };
 }
 
-bool RedirectAction::URLTransformAction::QueryTransform::QueryKeyValue::operator==(const QueryKeyValue& other) const
-{
-    return other.key == this->key
-        && other.replaceOnly == this->replaceOnly
-        && other.value == this->value;
-}
-
 void RedirectAction::URLTransformAction::QueryTransform::QueryKeyValue::serialize(Vector<uint8_t>& vector) const
 {
     constexpr auto headerLength = sizeof(uint32_t) + sizeof(uint32_t) + sizeof(bool);

Source/WebCore/contentextensions/ContentExtensionActions.h

@@ -43,7 +43,7 @@ using SerializedActionByte = uint8_t;
 
 template<typename T> struct ActionWithoutMetadata {
     T isolatedCopy() const { return { }; }
-    bool operator==(const ActionWithoutMetadata&) const { return true; }
+    friend bool operator==(const ActionWithoutMetadata&, const ActionWithoutMetadata&) = default;
     void serialize(Vector<uint8_t>&) const { }
     static T deserialize(std::span<const uint8_t>) { return { }; }
     static size_t serializedLength(std::span<const uint8_t>) { return 0; }
@@ -53,7 +53,7 @@ template<typename T> struct ActionWithStringMetadata {
     String string;
     T isolatedCopy() const & { return { { string.isolatedCopy() } }; }
     T isolatedCopy() && { return { { WTFMove(string).isolatedCopy() } }; }
-    bool operator==(const ActionWithStringMetadata& other) const { return other.string == this->string; }
+    friend bool operator==(const ActionWithStringMetadata&, const ActionWithStringMetadata&) = default;
     void serialize(Vector<uint8_t>& vector) const { serializeString(vector, string); }
     static T deserialize(std::span<const uint8_t> span) { return { { deserializeString(span) } }; }
     static size_t serializedLength(std::span<const uint8_t> span) { return stringSerializedLength(span); }
@@ -76,30 +76,30 @@ struct WEBCORE_EXPORT ModifyHeadersAction {
 
             AppendOperation isolatedCopy() const & { return { header.isolatedCopy(), value.isolatedCopy() }; }
             AppendOperation isolatedCopy() && { return { WTFMove(header).isolatedCopy(), WTFMove(value).isolatedCopy() }; }
-            bool operator==(const AppendOperation& other) const { return other.header == this->header && other.value == this->value; }
+            friend bool operator==(const AppendOperation&, const AppendOperation&) = default;
         };
         struct SetOperation {
             String header;
             String value;
 
             SetOperation isolatedCopy() const & { return { header.isolatedCopy(), value.isolatedCopy() }; }
             SetOperation isolatedCopy() && { return { WTFMove(header).isolatedCopy(), WTFMove(value).isolatedCopy() }; }
-            bool operator==(const SetOperation& other) const { return other.header == this->header && other.value == this->value; }
+            friend bool operator==(const SetOperation&, const SetOperation&) = default;
         };
         struct RemoveOperation {
             String header;
 
             RemoveOperation isolatedCopy() const & { return { header.isolatedCopy() }; }
             RemoveOperation isolatedCopy() && { return { WTFMove(header).isolatedCopy() }; }
-            bool operator==(const RemoveOperation& other) const { return other.header == this->header; }
+            friend bool operator==(const RemoveOperation&, const RemoveOperation&) = default;
         };
         using OperationVariant = std::variant<AppendOperation, SetOperation, RemoveOperation>;
         OperationVariant operation;
 
         static Expected<ModifyHeaderInfo, std::error_code> parse(const JSON::Value&);
         ModifyHeaderInfo isolatedCopy() const &;
         ModifyHeaderInfo isolatedCopy() &&;
-        bool operator==(const ModifyHeaderInfo&) const;
+        friend bool operator==(const ModifyHeaderInfo&, const ModifyHeaderInfo&) = default;
         void serialize(Vector<uint8_t>&) const;
         static ModifyHeaderInfo deserialize(std::span<const uint8_t>);
         static size_t serializedLength(std::span<const uint8_t>);
@@ -126,7 +126,7 @@ struct WEBCORE_EXPORT ModifyHeadersAction {
     static Expected<ModifyHeadersAction, std::error_code> parse(const JSON::Object&);
     ModifyHeadersAction isolatedCopy() const &;
     ModifyHeadersAction isolatedCopy() &&;
-    bool operator==(const ModifyHeadersAction&) const;
+    friend bool operator==(const ModifyHeadersAction&, const ModifyHeadersAction&) = default;
     void serialize(Vector<uint8_t>&) const;
     static ModifyHeadersAction deserialize(std::span<const uint8_t>);
     static size_t serializedLength(std::span<const uint8_t>);
@@ -139,7 +139,7 @@ struct WEBCORE_EXPORT RedirectAction {
 
         ExtensionPathAction isolatedCopy() const & { return { extensionPath.isolatedCopy() }; }
         ExtensionPathAction isolatedCopy() && { return { WTFMove(extensionPath).isolatedCopy() }; }
-        bool operator==(const ExtensionPathAction& other) const { return other.extensionPath == this->extensionPath; }
+        friend bool operator==(const ExtensionPathAction&, const ExtensionPathAction&) = default;
     };
     struct RegexSubstitutionAction {
         String regexSubstitution;
@@ -149,7 +149,7 @@ struct WEBCORE_EXPORT RedirectAction {
         RegexSubstitutionAction isolatedCopy() && { return { WTFMove(regexSubstitution).isolatedCopy(), WTFMove(regexFilter).isolatedCopy() }; }
         void serialize(Vector<uint8_t>&) const;
         static RegexSubstitutionAction deserialize(std::span<const uint8_t>);
-        bool operator==(const RegexSubstitutionAction& other) const { return other.regexSubstitution == this->regexSubstitution && other.regexFilter == this->regexFilter; }
+        friend bool operator==(const RegexSubstitutionAction&, const RegexSubstitutionAction&) = default;
         WEBCORE_EXPORT void applyToURL(URL&) const;
     };
     struct URLTransformAction {
@@ -162,7 +162,7 @@ struct WEBCORE_EXPORT RedirectAction {
                 static Expected<QueryKeyValue, std::error_code> parse(const JSON::Value&);
                 QueryKeyValue isolatedCopy() const & { return { key.isolatedCopy(), replaceOnly, value.isolatedCopy() }; }
                 QueryKeyValue isolatedCopy() && { return { WTFMove(key).isolatedCopy(), replaceOnly, WTFMove(value).isolatedCopy() }; }
-                bool operator==(const QueryKeyValue&) const;
+                friend bool operator==(const QueryKeyValue&, const QueryKeyValue&) = default;
                 void serialize(Vector<uint8_t>&) const;
                 static QueryKeyValue deserialize(std::span<const uint8_t>);
                 static size_t serializedLength(std::span<const uint8_t>);
@@ -174,7 +174,7 @@ struct WEBCORE_EXPORT RedirectAction {
             static Expected<QueryTransform, std::error_code> parse(const JSON::Object&);
             QueryTransform isolatedCopy() const &;
             QueryTransform isolatedCopy() &&;
-            bool operator==(const QueryTransform&) const;
+            friend bool operator==(const QueryTransform&, const QueryTransform&) = default;
             void serialize(Vector<uint8_t>&) const;
             static QueryTransform deserialize(std::span<const uint8_t>);
             static size_t serializedLength(std::span<const uint8_t>);
@@ -194,7 +194,7 @@ struct WEBCORE_EXPORT RedirectAction {
         static Expected<URLTransformAction, std::error_code> parse(const JSON::Object&);
         URLTransformAction isolatedCopy() const &;
         URLTransformAction isolatedCopy() &&;
-        bool operator==(const URLTransformAction&) const;
+        friend bool operator==(const URLTransformAction&, const URLTransformAction&) = default;
         void serialize(Vector<uint8_t>&) const;
         static URLTransformAction deserialize(std::span<const uint8_t>);
         static size_t serializedLength(std::span<const uint8_t>);
@@ -205,7 +205,7 @@ struct WEBCORE_EXPORT RedirectAction {
 
         URLAction isolatedCopy() const & { return { url.isolatedCopy() }; }
         URLAction isolatedCopy() && { return { WTFMove(url).isolatedCopy() }; }
-        bool operator==(const URLAction& other) const { return other.url == this->url; }
+        friend bool operator==(const URLAction&, const URLAction&) = default;
     };
 
     enum class HashTableType : uint8_t { Empty, Deleted, Full } hashTableType;
@@ -225,7 +225,7 @@ struct WEBCORE_EXPORT RedirectAction {
     static Expected<RedirectAction, std::error_code> parse(const JSON::Object&, const String& urlFilter);
     RedirectAction isolatedCopy() const &;
     RedirectAction isolatedCopy() &&;
-    bool operator==(const RedirectAction&) const;
+    friend bool operator==(const RedirectAction&, const RedirectAction&) = default;
     void serialize(Vector<uint8_t>&) const;
     static RedirectAction deserialize(std::span<const uint8_t>);
     static size_t serializedLength(std::span<const uint8_t>);

Source/WebCore/contentextensions/ContentExtensionRule.h

@@ -70,15 +70,7 @@ struct Trigger {
             && conditions.isEmpty();
     }
 
-    bool operator==(const Trigger& other) const
-    {
-        return urlFilter == other.urlFilter
-            && urlFilterIsCaseSensitive == other.urlFilterIsCaseSensitive
-            && topURLFilterIsCaseSensitive == other.topURLFilterIsCaseSensitive
-            && frameURLFilterIsCaseSensitive == other.frameURLFilterIsCaseSensitive
-            && flags == other.flags
-            && conditions == other.conditions;
-    }
+    friend bool operator==(const Trigger&, const Trigger&) = default;
 };
 
 inline void add(Hasher& hasher, const Trigger& trigger)
@@ -127,7 +119,7 @@ struct Action {
     Action(ActionData&& data)
         : m_data(WTFMove(data)) { }
 
-    bool operator==(const Action& other) const { return m_data == other.m_data; }
+    friend bool operator==(const Action&, const Action&) = default;
 
     const ActionData& data() const { return m_data; }
 
@@ -161,10 +153,7 @@ class ContentExtensionRule {
 
     ContentExtensionRule isolatedCopy() const & { return { m_trigger.isolatedCopy(), m_action.isolatedCopy() }; }
     ContentExtensionRule isolatedCopy() && { return { WTFMove(m_trigger).isolatedCopy(), WTFMove(m_action).isolatedCopy() }; }
-    bool operator==(const ContentExtensionRule& other) const
-    {
-        return m_trigger == other.m_trigger && m_action == other.m_action;
-    }
+    friend bool operator==(const ContentExtensionRule&, const ContentExtensionRule&) = default;
 
 private:
     Trigger m_trigger;

Source/WebCore/contentextensions/NFAToDFA.cpp

@@ -162,10 +162,7 @@ class UniqueNodeIdSet {
         fastFree(m_uniqueNodeIdSetBuffer);
     }
 
-    bool operator==(const UniqueNodeIdSet& other) const
-    {
-        return m_uniqueNodeIdSetBuffer == other.m_uniqueNodeIdSetBuffer;
-    }
+    friend bool operator==(const UniqueNodeIdSet&, const UniqueNodeIdSet&) = default;
 
     bool operator==(const NodeIdSet& other) const
     {

Source/WebCore/contentextensions/Term.h

@@ -158,12 +158,7 @@ class Term {
             return WTF::bitCount(m_characters[0]) + WTF::bitCount(m_characters[1]);
         }
 
-        bool operator==(const CharacterSet& other) const
-        {
-            return other.m_inverted == m_inverted
-                && other.m_characters[0] == m_characters[0]
-                && other.m_characters[1] == m_characters[1];
-        }
+        friend bool operator==(const CharacterSet&, const CharacterSet&) = default;
 
     private:
         friend void add(Hasher&, const CharacterSet&);
@@ -176,10 +171,7 @@ class Term {
     struct Group {
         Vector<Term> terms;
 
-        bool operator==(const Group& other) const
-        {
-            return other.terms == terms;
-        }
+        friend bool operator==(const Group&, const Group&) = default;
     };
     friend void add(Hasher&, const Term::Group&);
 

Source/WebCore/css/CSSCounterStyleDescriptors.h

@@ -43,7 +43,7 @@ struct CSSCounterStyleDescriptors {
     struct Symbol {
         bool isCustomIdent { false };
         String text;
-        bool operator==(const Symbol& other) const { return isCustomIdent == other.isCustomIdent && text == other.text; }
+        friend bool operator==(const Symbol&, const Symbol&) = default;
         String cssText() const;
     };
     using AdditiveSymbols = Vector<std::pair<Symbol, unsigned>>;
@@ -72,13 +72,13 @@ struct CSSCounterStyleDescriptors {
     struct Pad {
         unsigned m_padMinimumLength = 0;
         Symbol m_padSymbol;
-        bool operator==(const Pad& other) const { return m_padMinimumLength == other.m_padMinimumLength && m_padSymbol == other.m_padSymbol; }
+        friend bool operator==(const Pad&, const Pad&) = default;
         String cssText() const;
     };
     struct NegativeSymbols {
         Symbol m_prefix = { false, "-"_s };
         Symbol m_suffix;
-        bool operator==(const NegativeSymbols& other) const { return m_prefix == other.m_prefix && m_suffix == other.m_suffix; }
+        friend bool operator==(const NegativeSymbols&, const NegativeSymbols&) = default;
     };
     enum class ExplicitlySetDescriptors: uint16_t {
         System = 1 << 0,
@@ -97,6 +97,7 @@ struct CSSCounterStyleDescriptors {
     static CSSCounterStyleDescriptors create(AtomString name, const StyleProperties&);
     bool operator==(const CSSCounterStyleDescriptors& other) const
     {
+        // Intentionally doesn't check m_isExtendedResolved.
         return m_name == other.m_name
             && m_system == other.m_system
             && m_negativeSymbols == other.m_negativeSymbols