Useless changes

base/base/DecomposedFloat.h

@@ -51,11 +51,9 @@ struct DecomposedFloat
     /// Returns 0 for both +0. and -0.
     int sign() const
     {
-        return (exponent() == 0 && mantissa() == 0)
-            ? 0
-            : (isNegative()
-                ? -1
-                : 1);
+        if (exponent() == 0 && mantissa() == 0)
+            return 0;
+        return isNegative() ? -1 : 1;
     }
 
     uint16_t exponent() const

programs/git-import/git-import.cpp

@@ -233,7 +233,7 @@ struct Commit
 };
 
 
-enum class FileChangeType
+enum class FileChangeType : uint8_t
 {
     Add,
     Delete,
@@ -291,7 +291,7 @@ struct FileChange
 };
 
 
-enum class LineType
+enum class LineType : uint8_t
 {
     Empty,
     Comment,

programs/main.cpp

@@ -119,7 +119,7 @@ std::pair<std::string_view, std::string_view> clickhouse_short_names[] =
 };
 
 
-enum class InstructionFail
+enum class InstructionFail : uint8_t
 {
     NONE = 0,
     SSE3 = 1,

src/Access/AccessBackup.h

@@ -8,7 +8,7 @@
 namespace DB
 {
 class AccessControl;
-enum class AccessEntityType;
+enum class AccessEntityType : uint8_t;
 struct IAccessEntity;
 using AccessEntityPtr = std::shared_ptr<const IAccessEntity>;
 class AccessRightsElements;

src/Access/Common/AccessEntityType.h

@@ -7,7 +7,7 @@ namespace DB
 {
 
 /// Represents the type of an access entity (see the IAccessEntity class).
-enum class AccessEntityType
+enum class AccessEntityType : uint8_t
 {
     USER,
     ROLE,

src/Access/Common/AccessType.h

@@ -7,7 +7,7 @@ namespace DB
 {
 
 /// Represents an access type which can be granted on databases, tables, columns, etc.
-enum class AccessType
+enum class AccessType : uint8_t
 {
 /// Macro M should be defined as M(name, aliases, node_type, parent_group_name)
 /// where name is identifier with underscores (instead of spaces);

src/Access/Common/AuthenticationType.h

@@ -6,7 +6,7 @@
 namespace DB
 {
 
-enum class AuthenticationType
+enum class AuthenticationType : uint8_t
 {
     /// User doesn't have to enter password.
     NO_PASSWORD,

src/Access/Common/QuotaDefs.h

@@ -9,7 +9,7 @@ namespace DB
 using QuotaValue = UInt64;
 
 /// Kinds of resource what we wish to quota.
-enum class QuotaType
+enum class QuotaType : uint8_t
 {
     QUERIES,                                /// Number of queries.
     QUERY_SELECTS,                          /// Number of select queries.
@@ -45,7 +45,7 @@ struct QuotaTypeInfo
 
 /// Key to share quota consumption.
 /// Users with the same key share the same amount of resource.
-enum class QuotaKeyType
+enum class QuotaKeyType : uint8_t
 {
     NONE,       /// All users share the same quota.
     USER_NAME,  /// Connections with the same user name share the same quota.

src/Access/Common/RowPolicyDefs.h

@@ -25,7 +25,7 @@ struct RowPolicyName
 
 /// Types of the filters of row policies.
 /// Currently only RowPolicyFilterType::SELECT is supported.
-enum class RowPolicyFilterType
+enum class RowPolicyFilterType : uint8_t
 {
     /// Filter is a SQL conditional expression used to figure out which rows should be visible
     /// for user or available for modification. If the expression returns NULL or false for some rows

src/Access/IAccessStorage.h

@@ -24,7 +24,7 @@ namespace DB
 struct User;
 class Credentials;
 class ExternalAuthenticators;
-enum class AuthenticationType;
+enum class AuthenticationType : uint8_t;
 class BackupEntriesCollector;
 class RestorerFromBackup;
 

src/Access/LDAPClient.h

@@ -26,7 +26,7 @@ class LDAPClient
 public:
     struct SearchParams
     {
-        enum class Scope
+        enum class Scope : uint8_t
         {
             BASE,
             ONE_LEVEL,
@@ -57,20 +57,20 @@ public:
 
     struct Params
     {
-        enum class ProtocolVersion
+        enum class ProtocolVersion : uint8_t
         {
             V2,
             V3
         };
 
-        enum class TLSEnable
+        enum class TLSEnable : uint8_t
         {
             NO,
             YES_STARTTLS,
             YES
         };
 
-        enum class TLSProtocolVersion
+        enum class TLSProtocolVersion : uint8_t
         {
             SSL2,
             SSL3,
@@ -79,7 +79,7 @@ public:
             TLS1_2
         };
 
-        enum class TLSRequireCert
+        enum class TLSRequireCert : uint8_t
         {
             NEVER,
             ALLOW,
@@ -87,7 +87,7 @@ public:
             DEMAND
         };
 
-        enum class SASLMechanism
+        enum class SASLMechanism : uint8_t
         {
             UNKNOWN,
             SIMPLE

src/AggregateFunctions/AggregateFunctionGroupArray.cpp

@@ -43,7 +43,7 @@ namespace ErrorCodes
 namespace
 {
 
-enum class Sampler
+enum class Sampler : uint8_t
 {
     NONE,
     RNG,

src/AggregateFunctions/AggregateFunctionGroupArraySorted.cpp

@@ -47,7 +47,7 @@ namespace ErrorCodes
 namespace
 {
 
-enum class GroupArraySortedStrategy
+enum class GroupArraySortedStrategy : uint8_t
 {
     heap,
     sort

src/AggregateFunctions/AggregateFunctionKolmogorovSmirnovTest.cpp

@@ -31,7 +31,7 @@ namespace
 
 struct KolmogorovSmirnov : public StatisticalSample<Float64, Float64>
 {
-    enum class Alternative
+    enum class Alternative : uint8_t
     {
         TwoSided,
         Less,

src/AggregateFunctions/AggregateFunctionMannWhitney.cpp

@@ -39,7 +39,7 @@ struct MannWhitneyData : public StatisticalSample<Float64, Float64>
      *the probability of X being greater than Y is equal to the probability of Y being greater than X".
      *Or "the distribution F of first sample equals to the distribution G of second sample".
      *Then alternative for this hypothesis (H1) is "two-sided"(F != G), "less"(F < G), "greater" (F > G). */
-    enum class Alternative
+    enum class Alternative : uint8_t
     {
         TwoSided,
         Less,

src/AggregateFunctions/AggregateFunctionMaxIntersections.cpp

@@ -48,7 +48,7 @@ struct MaxIntersectionsData
     Array value;
 };
 
-enum class AggregateFunctionIntersectionsKind
+enum class AggregateFunctionIntersectionsKind : uint8_t
 {
     Count,
     Position

src/AggregateFunctions/AggregateFunctionSequenceMatch.cpp

@@ -184,7 +184,7 @@ public:
     }
 
 private:
-    enum class PatternActionType
+    enum class PatternActionType : uint8_t
     {
         SpecificEvent,
         AnyEvent,
@@ -577,7 +577,7 @@ protected:
     }
 
 private:
-    enum class DFATransition : char
+    enum class DFATransition : uint8_t
     {
         ///   .-------.
         ///   |       |

src/AggregateFunctions/AggregateFunctionSequenceNextNode.cpp

@@ -41,13 +41,13 @@ namespace ErrorCodes
 namespace
 {
 
-enum class SequenceDirection
+enum class SequenceDirection : uint8_t
 {
     Forward,
     Backward,
 };
 
-enum SequenceBase
+enum SequenceBase : uint8_t
 {
     Head,
     Tail,

src/AggregateFunctions/AggregateFunctionStatistics.cpp

@@ -104,7 +104,7 @@ struct AggregateFunctionVarianceData
     Float64 m2 = 0.0;
 };
 
-enum class VarKind
+enum class VarKind : uint8_t
 {
     varSampStable,
     stddevSampStable,
@@ -343,7 +343,7 @@ struct CovarianceData : public BaseCovarianceData<compute_marginal_moments>
     Float64 co_moment = 0.0;
 };
 
-enum class CovarKind
+enum class CovarKind : uint8_t
 {
     covarSampStable,
     covarPopStable,

src/AggregateFunctions/AggregateFunctionStatisticsSimple.h

@@ -35,7 +35,7 @@ namespace DB
 
 struct Settings;
 
-enum class StatisticsFunctionKind
+enum class StatisticsFunctionKind : uint8_t
 {
     varPop, varSamp,
     stddevPop, stddevSamp,

src/AggregateFunctions/AggregateFunctionVarianceMatrix.cpp

@@ -20,7 +20,7 @@ namespace ErrorCodes
 namespace
 {
 
-enum class StatisticsMatrixFunctionKind
+enum class StatisticsMatrixFunctionKind : uint8_t
 {
     covarPopMatrix,
     covarSampMatrix,

src/AggregateFunctions/Combinators/AggregateFunctionOrFill.cpp

@@ -7,7 +7,7 @@ namespace DB
 namespace
 {
 
-enum class Kind
+enum class Kind : uint8_t
 {
     OrNull,
     OrDefault

src/AggregateFunctions/ReservoirSamplerDeterministic.h

@@ -50,7 +50,7 @@ namespace detail
 }
 
 /// What if there is not a single value - throw an exception, or return 0 or NaN in the case of double?
-enum class ReservoirSamplerDeterministicOnEmpty
+enum class ReservoirSamplerDeterministicOnEmpty : uint8_t
 {
     THROW,
     RETURN_NAN_OR_ZERO,

src/Analyzer/ColumnTransformers.h

@@ -61,7 +61,7 @@ namespace DB
   */
 
 /// Column transformer type
-enum class ColumnTransfomerType
+enum class ColumnTransfomerType : uint8_t
 {
     APPLY,
     EXCEPT,
@@ -98,7 +98,7 @@ protected:
     explicit IColumnTransformerNode(size_t children_size);
 };
 
-enum class ApplyColumnTransformerType
+enum class ApplyColumnTransformerType : uint8_t
 {
     LAMBDA,
     FUNCTION
@@ -153,7 +153,7 @@ private:
 };
 
 /// Except column transformer type
-enum class ExceptColumnTransformerType
+enum class ExceptColumnTransformerType : uint8_t
 {
     REGEXP,
     COLUMN_LIST,

src/Analyzer/IQueryTreeNode.h

@@ -25,7 +25,7 @@ namespace ErrorCodes
 class WriteBuffer;
 
 /// Query tree node type
-enum class QueryTreeNodeType
+enum class QueryTreeNodeType : uint8_t
 {
     IDENTIFIER,
     MATCHER,

src/Analyzer/MatcherNode.h

@@ -37,7 +37,7 @@ namespace DB
   * Additionally each matcher can contain transformers, check ColumnTransformers.h.
   * In query tree matchers column transformers are represended as ListNode.
   */
-enum class MatcherNodeType
+enum class MatcherNodeType : uint8_t
 {
     ASTERISK,
     COLUMNS_REGEXP,

src/Analyzer/Passes/GroupingFunctionsResolvePass.cpp

@@ -24,7 +24,7 @@ namespace ErrorCodes
 namespace
 {
 
-enum class GroupByKind
+enum class GroupByKind : uint8_t
 {
     ORDINARY,
     ROLLUP,
@@ -256,4 +256,3 @@ void GroupingFunctionsResolvePass::run(QueryTreeNodePtr & query_tree_node, Conte
 }
 
 }
-

src/Analyzer/SortNode.h

@@ -15,7 +15,7 @@ namespace DB
 class SortNode;
 using SortNodePtr = std::shared_ptr<SortNode>;
 
-enum class SortDirection
+enum class SortDirection : uint8_t
 {
     ASCENDING = 0,
     DESCENDING = 1

src/Backups/BackupCoordinationReplicatedAccess.h

@@ -7,7 +7,7 @@
 
 namespace DB
 {
-enum class AccessEntityType;
+enum class AccessEntityType : uint8_t;
 
 /// This class is used by hosts to coordinate the access entities of ReplicatedAccessStorage they're writing to a backup.
 /// It's designed to make all hosts save the same access entities to the backup even in case the ReplicatedAccessStorage changes

src/Backups/BackupCoordinationReplicatedSQLObjects.h

@@ -7,7 +7,7 @@
 
 namespace DB
 {
-enum class UserDefinedSQLObjectType;
+enum class UserDefinedSQLObjectType : uint8_t;
 
 /// This class is used by hosts to coordinate the user-defined SQL objects they're going to write to a backup.
 /// It's designed to make all hosts save the same objects to the backup even in case some objects change while

src/Backups/BackupEntriesCollector.cpp

@@ -689,7 +689,13 @@ bool BackupEntriesCollector::compareWithPrevious(String & mismatch_description)
         previous_tables_metadata = std::move(tables_metadata);
     });
 
-    enum class MismatchType { ADDED, REMOVED, CHANGED, NONE };
+    enum class MismatchType : uint8_t
+    {
+        ADDED,
+        REMOVED,
+        CHANGED,
+        NONE
+    };
 
     /// Helper function - used to compare the metadata of databases and tables.
     auto find_mismatch = [](const auto & metadata, const auto & previous_metadata)

src/Backups/BackupEntriesCollector.h

@@ -21,7 +21,7 @@ class IBackupCoordination;
 class IDatabase;
 using DatabasePtr = std::shared_ptr<IDatabase>;
 struct StorageID;
-enum class AccessEntityType;
+enum class AccessEntityType : uint8_t;
 class QueryStatus;
 using QueryStatusPtr = std::shared_ptr<QueryStatus>;
 

src/Backups/BackupFileInfo.cpp

@@ -27,7 +27,7 @@ namespace
         return std::nullopt;
     }
 
-    enum class CheckBackupResult
+    enum class CheckBackupResult : uint8_t
     {
         HasPrefix,
         HasFull,

src/Backups/BackupIO.h

@@ -9,7 +9,7 @@ class IDisk;
 using DiskPtr = std::shared_ptr<IDisk>;
 class SeekableReadBuffer;
 class WriteBuffer;
-enum class WriteMode;
+enum class WriteMode : uint8_t;
 struct WriteSettings;
 struct ReadSettings;
 

src/Backups/BackupIO_Default.h

@@ -13,7 +13,7 @@ using DiskPtr = std::shared_ptr<IDisk>;
 class ReadBuffer;
 class SeekableReadBuffer;
 class WriteBuffer;
-enum class WriteMode;
+enum class WriteMode : uint8_t;
 
 /// Represents operations of loading from disk or downloading for reading a backup.
 class BackupReaderDefault : public IBackupReader

src/Backups/BackupStatus.h

@@ -6,7 +6,7 @@
 namespace DB
 {
 
-enum class BackupStatus
+enum class BackupStatus : uint8_t
 {
     /// Statuses of making backups
     CREATING_BACKUP,

src/Backups/BackupsWorker.cpp

@@ -256,7 +256,7 @@ namespace
 /// 1) there should be separate thread pools for BACKUP and RESTORE;
 /// 2) a task from a thread pool can't wait another task from the same thread pool. (Because if it schedules and waits
 /// while the thread pool is still occupied with the waiting task then a scheduled task can be never executed).
-enum class BackupsWorker::ThreadPoolId
+enum class BackupsWorker::ThreadPoolId : uint8_t
 {
     /// "BACKUP ON CLUSTER ASYNC" waits in background while "BACKUP ASYNC" is finished on the nodes of the cluster, then finalizes the backup.
     BACKUP_ASYNC_ON_CLUSTER,

src/Backups/BackupsWorker.h

@@ -107,7 +107,7 @@ private:
     void setNumFilesAndSize(const BackupOperationID & id, size_t num_files, UInt64 total_size, size_t num_entries,
                             UInt64 uncompressed_size, UInt64 compressed_size, size_t num_read_files, UInt64 num_read_bytes);
 
-    enum class ThreadPoolId;
+    enum class ThreadPoolId : uint8_t;
     ThreadPool & getThreadPool(ThreadPoolId thread_pool_id);
 
     /// Waits for some time if `test_inject_sleep` is true.

src/Backups/IBackup.h

@@ -28,7 +28,7 @@ public:
     //virtual const String & getName() const = 0;
     virtual const String & getNameForLogging() const = 0;
 
-    enum class OpenMode
+    enum class OpenMode : uint8_t
     {
         READ,
         WRITE,

src/Backups/IBackupCoordination.h

@@ -8,8 +8,8 @@ namespace DB
 class Exception;
 struct BackupFileInfo;
 using BackupFileInfos = std::vector<BackupFileInfo>;
-enum class AccessEntityType;
-enum class UserDefinedSQLObjectType;
+enum class AccessEntityType : uint8_t;
+enum class UserDefinedSQLObjectType : uint8_t;
 
 /// Replicas use this class to coordinate what they're writing to a backup while executing BACKUP ON CLUSTER.
 /// There are two implementation of this interface: BackupCoordinationLocal and BackupCoordinationRemote.

src/Backups/IRestoreCoordination.h

@@ -6,7 +6,7 @@
 namespace DB
 {
 class Exception;
-enum class UserDefinedSQLObjectType;
+enum class UserDefinedSQLObjectType : uint8_t;
 class ASTCreateQuery;
 
 /// Replicas use this class to coordinate what they're reading from a backup while executing RESTORE ON CLUSTER.

src/Backups/RestoreSettings.h

@@ -9,7 +9,7 @@ namespace DB
 class ASTBackupQuery;
 
 /// How the RESTORE command will handle table/database existence.
-enum class RestoreTableCreationMode
+enum class RestoreTableCreationMode : uint8_t
 {
     /// RESTORE TABLE always tries to create a table and it throws an exception if the table already exists.
     kCreate,
@@ -24,7 +24,7 @@ enum class RestoreTableCreationMode
 using RestoreDatabaseCreationMode = RestoreTableCreationMode;
 
 /// How the RESTORE command will handle if an user (or role or profile) which it's going to restore already exists.
-enum class RestoreAccessCreationMode
+enum class RestoreAccessCreationMode : uint8_t
 {
     /// RESTORE will throw an exception if some user already exists.
     kCreate,

src/Client/ConnectionPoolWithFailover.h

@@ -22,7 +22,7 @@ namespace DB
   */
 
 /// Specifies how many connections to return from ConnectionPoolWithFailover::getMany() method.
-enum class PoolMode
+enum class PoolMode : uint8_t
 {
     /// Return exactly one connection.
     GET_ONE = 0,

src/Client/HedgedConnectionsFactory.h

@@ -27,7 +27,7 @@ public:
     using ShuffledPool = ConnectionPoolWithFailover::Base::ShuffledPool;
     using TryResult = PoolWithFailoverBase<IConnectionPool>::TryResult;
 
-    enum class State
+    enum class State : uint8_t
     {
         READY,
         NOT_READY,

src/Client/IServerConnection.h

@@ -68,7 +68,7 @@ class IServerConnection : boost::noncopyable
 public:
     virtual ~IServerConnection() = default;
 
-    enum class Type
+    enum class Type : uint8_t
     {
         SERVER,
         LOCAL

src/Common/AsyncLoader.h

@@ -44,7 +44,7 @@ class AsyncLoader;
 void logAboutProgress(LoggerPtr log, size_t processed, size_t total, AtomicStopwatch & watch);
 
 // Execution status of a load job.
-enum class LoadStatus
+enum class LoadStatus : uint8_t
 {
     PENDING,  // Load job is not started yet.
     OK,       // Load job executed and was successful.

src/Common/AsyncTaskExecutor.h

@@ -13,7 +13,7 @@
 namespace DB
 {
 
-enum class AsyncEventTimeoutType
+enum class AsyncEventTimeoutType : uint8_t
 {
     CONNECT,
     RECEIVE,

src/Common/CgroupsMemoryUsageObserver.h

@@ -30,7 +30,7 @@ public:
     using OnMemoryLimitFn = std::function<void(bool)>;
     using OnMemoryAmountAvailableChangedFn = std::function<void()>;
 
-    enum class CgroupsVersion
+    enum class CgroupsVersion : uint8_t
     {
         V1,
         V2

src/Common/ColumnsHashing.h

@@ -235,7 +235,7 @@ struct HashMethodSingleLowCardinalityColumn : public SingleColumnMethod
 {
     using Base = SingleColumnMethod;
 
-    enum class VisitValue
+    enum class VisitValue : uint8_t
     {
         Empty = 0,
         Found = 1,

src/Common/CombinedCardinalityEstimator.h

@@ -16,7 +16,12 @@ namespace ErrorCodes
 namespace details
 {
 
-enum class ContainerType : uint8_t { SMALL = 1, MEDIUM = 2, LARGE = 3 };
+enum class ContainerType : uint8_t
+{
+    SMALL = 1,
+    MEDIUM = 2,
+    LARGE = 3
+};
 
 static inline ContainerType max(const ContainerType & lhs, const ContainerType & rhs)
 {

src/Common/DateLUTImpl.h

@@ -41,7 +41,7 @@ enum class WeekModeFlag : UInt8
 using YearWeek = std::pair<UInt16, UInt8>;
 
 /// Modes for toDayOfWeek() function.
-enum class WeekDayMode
+enum class WeekDayMode : uint8_t
 {
     WeekStartsMonday1 = 0,
     WeekStartsMonday0 = 1,

src/Common/Dwarf.h

@@ -126,7 +126,7 @@ public:
         std::string_view name;
     };
 
-    enum class LocationInfoMode
+    enum class LocationInfoMode : uint8_t
     {
         // Don't resolve location info.
         DISABLED,

src/Common/FST.h

@@ -70,7 +70,7 @@ class State
 {
 public:
     static constexpr size_t MAX_ARCS_IN_SEQUENTIAL_METHOD = 32;
-    enum class EncodingMethod
+    enum class EncodingMethod : uint8_t
     {
         /// Serialize arcs sequentially
         Sequential = 0,

src/Common/HTTPConnectionPool.h

@@ -52,7 +52,7 @@ protected:
 
 };
 
-enum class HTTPConnectionGroupType
+enum class HTTPConnectionGroupType : uint8_t
 {
     DISK,
     STORAGE,

src/Common/HyperLogLogCounter.h

@@ -27,7 +27,7 @@ namespace ErrorCodes
 
 
 /// Sets denominator type.
-enum class DenominatorMode
+enum class DenominatorMode : uint8_t
 {
     Compact,        /// Compact denominator.
     StableIfBig,    /// Stable denominator falling back to Compact if rank storage is not big enough.
@@ -246,7 +246,7 @@ struct RankWidth<UInt64>
 
 
 /// Sets behavior of HyperLogLog class.
-enum class HyperLogLogMode
+enum class HyperLogLogMode : uint8_t
 {
     Raw,            /// No error correction.
     LinearCounting, /// LinearCounting error correction.

src/Common/IntervalKind.h

@@ -7,7 +7,7 @@ namespace DB
 /// Kind of a temporal interval.
 struct IntervalKind
 {
-    enum class Kind
+    enum class Kind : uint8_t
     {
         Nanosecond,
         Microsecond,

src/Common/JSONParsers/ElementTypes.h

@@ -3,7 +3,7 @@
 namespace DB
 {
 // Enum values match simdjson's for fast conversion
-enum class ElementType
+enum class ElementType : uint8_t
 {
     ARRAY = '[',
     OBJECT = '{',

src/Common/NamedCollections/NamedCollectionUtils.h

@@ -13,7 +13,7 @@ class ASTDropNamedCollectionQuery;
 namespace NamedCollectionUtils
 {
 
-enum class SourceId
+enum class SourceId : uint8_t
 {
     NONE = 0,
     CONFIG = 1,

src/Common/OvercommitTracker.h

@@ -42,7 +42,7 @@ namespace DB
     struct ProcessListForUser;
 }
 
-enum class OvercommitResult
+enum class OvercommitResult : uint8_t
 {
     NONE,
     DISABLED,
@@ -52,7 +52,7 @@ enum class OvercommitResult
     NOT_ENOUGH_FREED,
 };
 
-enum class QueryCancellationState
+enum class QueryCancellationState : uint8_t
 {
     NONE     = 0,  // Hard limit is not reached, there is no selected query to kill.
     SELECTED = 1,  // Hard limit is reached, query to stop was chosen but it still is not aware of cancellation.

src/Common/PageCache.h

@@ -103,7 +103,7 @@ struct AtomicBitSet
     void unsetAll() const;
 };
 
-enum class PageChunkState
+enum class PageChunkState : uint8_t
 {
     /// Pages are not reclaimable by the OS, the buffer has correct contents.
     Stable,

src/Common/ProxyConfiguration.h

@@ -13,7 +13,7 @@ namespace ErrorCodes
 
 struct ProxyConfiguration
 {
-    enum class Protocol
+    enum class Protocol : uint8_t
     {
         HTTP,
         HTTPS

src/Common/SettingConstraintWritability.h

@@ -4,7 +4,7 @@
 namespace DB
 {
 
-enum class SettingConstraintWritability
+enum class SettingConstraintWritability : uint8_t
 {
     // Default. Setting can be change within specified range only in `readonly=0` or `readonly=2` mode.
     WRITABLE,

src/Common/ShellCommandSettings.h

@@ -5,7 +5,7 @@
 namespace DB
 {
 
-enum class ExternalCommandStderrReaction
+enum class ExternalCommandStderrReaction : uint8_t
 {
     NONE, /// Do nothing.
     LOG, /// Try to log all outputs of stderr from the external command immediately.

src/Common/ThreadProfileEvents.h

@@ -189,7 +189,7 @@ extern PerfEventsCounters current_thread_counters;
 class TasksStatsCounters
 {
 public:
-    enum class MetricsProvider
+    enum class MetricsProvider : uint8_t
     {
         None,
         Procfs,

src/Common/VariableContext.h

@@ -1,8 +1,10 @@
 #pragma once
 
+#include <cstdint>
+
 /// Used in ProfileEvents and MemoryTracker to determine their hierarchy level
 /// The less value the higher level (zero level is the root)
-enum class VariableContext
+enum class VariableContext : uint8_t
 {
     Global = 0,
     User,           /// Group of processes

src/Common/ZooKeeper/ZooKeeperCachingGetter.h

@@ -8,7 +8,7 @@ namespace zkutil
 class ZooKeeperCachingGetter : boost::noncopyable
 {
 public:
-    enum class SessionStatus
+    enum class SessionStatus : uint8_t
     {
         New,
         Cached

src/Common/ZooKeeper/ZooKeeperCommon.h

@@ -625,7 +625,7 @@ private:
     ZooKeeperRequestFactory();
 };
 
-enum class PathMatchResult
+enum class PathMatchResult : uint8_t
 {
     NOT_MATCH,
     EXACT,

src/Common/examples/arena_with_free_lists.cpp

@@ -137,7 +137,7 @@ struct Dictionary
     template <typename Value> using ContainerType = Value[];
     template <typename Value> using ContainerPtrType = std::unique_ptr<ContainerType<Value>>;
 
-    enum class AttributeUnderlyingTypeTest
+    enum class AttributeUnderlyingTypeTest : uint8_t
     {
         UInt8,
         UInt16,

src/Common/filesystemHelpers.h

@@ -28,7 +28,7 @@ String getBlockDeviceId([[maybe_unused]] const String & path);
 
 std::optional<String> tryGetBlockDeviceId([[maybe_unused]] const String & path);
 
-enum class BlockDeviceType
+enum class BlockDeviceType : uint8_t
 {
     UNKNOWN = 0, // we were unable to determine device type
     NONROT = 1, // not a rotational device (SSD, NVME, etc)

src/Compression/CompressionCodecT64.cpp

@@ -27,7 +27,7 @@ public:
     /// There're 2 compression variants:
     /// Byte - transpose bit matrix by bytes (only the last not full byte is transposed by bits). It's default.
     /// Bits - full bit-transpose of the bit matrix. It uses more resources and leads to better compression with ZSTD (but worse with LZ4).
-    enum class Variant
+    enum class Variant : uint8_t
     {
         Byte,
         Bit

src/Compression/ICompressionCodec.h

@@ -54,7 +54,7 @@ public:
     /// --- For the codec with HW decompressor, it means submit request to HW and return immediately.
     /// --- Must be used in pair with flushAsynchronousDecompressRequests.
     /// SoftwareFallback mode is exclusively defined for the codec with HW decompressor, enable its capability of "fallback to SW codec".
-    enum class CodecMode
+    enum class CodecMode : uint8_t
     {
         Synchronous,
         Asynchronous,

src/Coordination/KeeperServer.h

@@ -128,7 +128,13 @@ public:
 
     int getServerID() const { return server_id; }
 
-    enum class ConfigUpdateState { Accepted, Declined, WaitBeforeChangingLeader };
+    enum class ConfigUpdateState : uint8_t
+    {
+        Accepted,
+        Declined,
+        WaitBeforeChangingLeader
+    };
+
     ConfigUpdateState applyConfigUpdate(
         const ClusterUpdateAction& action,
         bool last_command_was_leader_change = false);

src/Coordination/Standalone/Context.h

@@ -127,7 +127,7 @@ public:
     std::shared_ptr<FilesystemReadPrefetchesLog> getFilesystemReadPrefetchesLog() const;
     std::shared_ptr<BlobStorageLog> getBlobStorageLog() const;
 
-    enum class ApplicationType
+    enum class ApplicationType : uint8_t
     {
         KEEPER
     };

src/Core/BaseSettings.h

@@ -20,7 +20,7 @@ namespace DB
 class ReadBuffer;
 class WriteBuffer;
 
-enum class SettingsWriteFormat
+enum class SettingsWriteFormat : uint8_t
 {
     BINARY,             /// Part of the settings are serialized as strings, and other part as variants. This is the old behaviour.
     STRINGS_WITH_FLAGS, /// All settings are serialized as strings. Before each value the flag `is_important` is serialized.

src/Core/Joins.h

@@ -6,7 +6,7 @@ namespace DB
 {
 
 /// Join method.
-enum class JoinKind
+enum class JoinKind : uint8_t
 {
     Inner, /// Leave only rows that was JOINed.
     Left, /// If in "right" table there is no corresponding rows, use default values instead.
@@ -31,7 +31,7 @@ inline constexpr bool isInnerOrLeft(JoinKind kind)  { return kind == JoinKind::I
 inline constexpr bool isPaste(JoinKind kind)        { return kind == JoinKind::Paste; }
 
 /// Allows more optimal JOIN for typical cases.
-enum class JoinStrictness
+enum class JoinStrictness : uint8_t
 {
     Unspecified,
     RightAny, /// Old ANY JOIN. If there are many suitable rows in right table, use any from them to join.
@@ -45,7 +45,7 @@ enum class JoinStrictness
 const char * toString(JoinStrictness strictness);
 
 /// Algorithm for distributed query processing.
-enum class JoinLocality
+enum class JoinLocality : uint8_t
 {
     Unspecified,
     Local, /// Perform JOIN, using only data available on same servers (co-located data).
@@ -55,7 +55,7 @@ enum class JoinLocality
 const char * toString(JoinLocality locality);
 
 /// ASOF JOIN inequality type
-enum class ASOFJoinInequality
+enum class ASOFJoinInequality : uint8_t
 {
     None,
     Less,
@@ -96,7 +96,7 @@ inline constexpr ASOFJoinInequality reverseASOFJoinInequality(ASOFJoinInequality
     return ASOFJoinInequality::None;
 }
 
-enum class JoinAlgorithm
+enum class JoinAlgorithm : uint8_t
 {
     DEFAULT = 0,
     AUTO,
@@ -111,7 +111,7 @@ enum class JoinAlgorithm
 
 const char * toString(JoinAlgorithm join_algorithm);
 
-enum class JoinTableSide
+enum class JoinTableSide : uint8_t
 {
     Left,
     Right

src/Core/LogsLevel.h

@@ -2,7 +2,7 @@
 
 namespace DB
 {
-enum class LogsLevel
+enum class LogsLevel : uint8_t
 {
     none = 0, /// Disable
     fatal,

src/Core/Protocol.h

@@ -190,14 +190,14 @@ namespace Protocol
     }
 
     /// Whether the compression must be used.
-    enum class Compression
+    enum class Compression : uint8_t
     {
         Disable = 0,
         Enable = 1,
     };
 
     /// Whether the ssl must be used.
-    enum class Secure
+    enum class Secure : uint8_t
     {
         Disable = 0,
         Enable = 1,

src/Core/SettingsEnums.h

@@ -115,7 +115,7 @@ constexpr auto getEnumValues();
         return getEnumValues<EnumType>().size();\
     }
 
-enum class LoadBalancing
+enum class LoadBalancing : uint8_t
 {
     /// among replicas with a minimum number of errors selected randomly
     RANDOM = 0,
@@ -142,7 +142,7 @@ DECLARE_SETTING_MULTI_ENUM(JoinAlgorithm)
 
 
 /// Which rows should be included in TOTALS.
-enum class TotalsMode
+enum class TotalsMode : uint8_t
 {
     BEFORE_HAVING            = 0, /// Count HAVING for all read rows;
                                   ///  including those not in max_rows_to_group_by
@@ -164,7 +164,7 @@ DECLARE_SETTING_ENUM_WITH_RENAME(OverflowModeGroupBy, OverflowMode)
 
 
 /// The setting for executing distributed subqueries inside IN or JOIN sections.
-enum class DistributedProductMode
+enum class DistributedProductMode : uint8_t
 {
     DENY = 0,    /// Disable
     LOCAL,       /// Convert to local query
@@ -175,7 +175,7 @@ enum class DistributedProductMode
 DECLARE_SETTING_ENUM(DistributedProductMode)
 
 /// How the query cache handles queries with non-deterministic functions, e.g. now()
-enum class QueryCacheNondeterministicFunctionHandling
+enum class QueryCacheNondeterministicFunctionHandling : uint8_t
 {
     Throw,
     Save,
@@ -185,7 +185,7 @@ enum class QueryCacheNondeterministicFunctionHandling
 DECLARE_SETTING_ENUM(QueryCacheNondeterministicFunctionHandling)
 
 /// How the query cache handles queries against system tables, tables in databases 'system.*' and 'information_schema.*'
-enum class QueryCacheSystemTableHandling
+enum class QueryCacheSystemTableHandling : uint8_t
 {
     Throw,
     Save,
@@ -217,7 +217,7 @@ enum QueryLogElementType : int8_t
 DECLARE_SETTING_ENUM_WITH_RENAME(LogQueriesType, QueryLogElementType)
 
 
-enum class DefaultDatabaseEngine
+enum class DefaultDatabaseEngine : uint8_t
 {
     Ordinary,
     Atomic,
@@ -225,7 +225,7 @@ enum class DefaultDatabaseEngine
 
 DECLARE_SETTING_ENUM(DefaultDatabaseEngine)
 
-enum class DefaultTableEngine
+enum class DefaultTableEngine : uint8_t
 {
     None = 0, /// Disable. Need to use ENGINE =
     Log,
@@ -242,7 +242,7 @@ enum class DefaultTableEngine
 DECLARE_SETTING_ENUM(DefaultTableEngine)
 
 
-enum class CleanDeletedRows
+enum class CleanDeletedRows : uint8_t
 {
     Never = 0, /// Disable.
     Always,
@@ -250,7 +250,7 @@ enum class CleanDeletedRows
 
 DECLARE_SETTING_ENUM(CleanDeletedRows)
 
-enum class MySQLDataTypesSupport
+enum class MySQLDataTypesSupport : uint8_t
 {
     DECIMAL, // convert MySQL's decimal and number to ClickHouse Decimal when applicable
     DATETIME64, // convert MySQL's DATETIME and TIMESTAMP and ClickHouse DateTime64 if precision is > 0 or range is greater that for DateTime.
@@ -260,7 +260,7 @@ enum class MySQLDataTypesSupport
 
 DECLARE_SETTING_MULTI_ENUM(MySQLDataTypesSupport)
 
-enum class SetOperationMode
+enum class SetOperationMode : uint8_t
 {
     Unspecified = 0, // Query UNION / EXCEPT / INTERSECT without SetOperationMode will throw exception
     ALL, // Query UNION / EXCEPT / INTERSECT without SetOperationMode -> SELECT ... UNION / EXCEPT / INTERSECT ALL SELECT ...
@@ -269,7 +269,7 @@ enum class SetOperationMode
 
 DECLARE_SETTING_ENUM(SetOperationMode)
 
-enum class DistributedDDLOutputMode
+enum class DistributedDDLOutputMode : uint8_t
 {
     NONE,
     THROW,
@@ -282,7 +282,7 @@ enum class DistributedDDLOutputMode
 
 DECLARE_SETTING_ENUM(DistributedDDLOutputMode)
 
-enum class StreamingHandleErrorMode
+enum class StreamingHandleErrorMode : uint8_t
 {
     DEFAULT = 0, // Ignore errors with threshold.
     STREAM, // Put errors to stream in the virtual column named ``_error.
@@ -292,7 +292,7 @@ enum class StreamingHandleErrorMode
 
 DECLARE_SETTING_ENUM(StreamingHandleErrorMode)
 
-enum class ShortCircuitFunctionEvaluation
+enum class ShortCircuitFunctionEvaluation : uint8_t
 {
     ENABLE, // Use short-circuit function evaluation for functions that are suitable for it.
     FORCE_ENABLE, // Use short-circuit function evaluation for all functions.
@@ -301,7 +301,7 @@ enum class ShortCircuitFunctionEvaluation
 
 DECLARE_SETTING_ENUM(ShortCircuitFunctionEvaluation)
 
-enum class TransactionsWaitCSNMode
+enum class TransactionsWaitCSNMode : uint8_t
 {
     ASYNC,
     WAIT,
@@ -322,7 +322,7 @@ DECLARE_SETTING_ENUM_WITH_RENAME(ArrowCompression, FormatSettings::ArrowCompress
 
 DECLARE_SETTING_ENUM_WITH_RENAME(ORCCompression, FormatSettings::ORCCompression)
 
-enum class Dialect
+enum class Dialect : uint8_t
 {
     clickhouse,
     kusto,
@@ -341,7 +341,7 @@ DECLARE_SETTING_ENUM(ParallelReplicasCustomKeyFilterType)
 
 DECLARE_SETTING_ENUM(LocalFSReadMethod)
 
-enum class S3QueueMode
+enum class S3QueueMode : uint8_t
 {
     ORDERED,
     UNORDERED,
@@ -349,7 +349,7 @@ enum class S3QueueMode
 
 DECLARE_SETTING_ENUM(S3QueueMode)
 
-enum class S3QueueAction
+enum class S3QueueAction : uint8_t
 {
     KEEP,
     DELETE,
@@ -359,7 +359,7 @@ DECLARE_SETTING_ENUM(S3QueueAction)
 
 DECLARE_SETTING_ENUM(ExternalCommandStderrReaction)
 
-enum class SchemaInferenceMode
+enum class SchemaInferenceMode : uint8_t
 {
     DEFAULT,
     UNION,

src/Core/SettingsFields.h

@@ -165,7 +165,11 @@ private:
 };
 
 
-enum class SettingFieldTimespanUnit { Millisecond, Second };
+enum class SettingFieldTimespanUnit : uint8_t
+{
+    Millisecond,
+    Second
+};
 
 template <SettingFieldTimespanUnit unit_>
 struct SettingFieldTimespan

src/Core/SortCursor.h

@@ -334,7 +334,7 @@ struct SortCursorWithCollation : SortCursorHelper<SortCursorWithCollation>
     }
 };
 
-enum class SortingQueueStrategy
+enum class SortingQueueStrategy : uint8_t
 {
     Default,
     Batch

src/Core/TypeId.h

@@ -6,7 +6,7 @@ namespace DB
 {
 
 /// @note Except explicitly described you should not assume on TypeIndex numbers and/or their orders in this enum.
-enum class TypeIndex
+enum class TypeIndex : uint8_t
 {
     Nothing = 0,
     UInt8,

src/Core/Types.h

@@ -21,7 +21,7 @@ namespace DB
 /// comparison which is used for nullable KeyCondition.
 struct Null
 {
-    enum class Value
+    enum class Value : int8_t
     {
         NegativeInfinity = -1,
         Null = 0,

src/Core/Types_fwd.h

@@ -32,7 +32,7 @@ struct IPv6;
 
 struct Null;
 
-enum class TypeIndex;
+enum class TypeIndex : uint8_t;
 
 /// Not a data type in database, defined just for convenience.
 using Strings = std::vector<String>;

src/DataTypes/convertMySQLDataType.h

@@ -7,7 +7,7 @@
 
 namespace DB
 {
-enum class MySQLDataTypesSupport;
+enum class MySQLDataTypesSupport : uint8_t;
 
 /// Convert MySQL type to ClickHouse data type.
 DataTypePtr convertMySQLDataType(MultiEnum<MySQLDataTypesSupport> type_support, const std::string & mysql_data_type, bool is_nullable, bool is_unsigned, size_t length, size_t precision, size_t scale);

src/DataTypes/getLeastSupertype.h

@@ -4,7 +4,7 @@
 namespace DB
 {
 
-enum class LeastSupertypeOnError
+enum class LeastSupertypeOnError : uint8_t
 {
     Throw,
     String,

src/DataTypes/registerDataTypeDateTime.cpp

@@ -16,7 +16,7 @@ namespace ErrorCodes
     extern const int ILLEGAL_TYPE_OF_ARGUMENT;
 }
 
-enum class ArgumentKind
+enum class ArgumentKind : uint8_t
 {
     Optional,
     Mandatory

src/Databases/LoadingStrictnessLevel.h

@@ -1,10 +1,13 @@
 #pragma once
 
+#include <cstdint>
+
+
 namespace DB
 {
 
 /// Strictness mode for loading a table or database
-enum class LoadingStrictnessLevel
+enum class LoadingStrictnessLevel : uint8_t
 {
     /// Do all possible sanity checks
     CREATE = 0,

src/Databases/MySQL/DatabaseMySQL.h

@@ -27,7 +27,7 @@ namespace DB
 
 class Context;
 
-enum class MySQLDataTypesSupport;
+enum class MySQLDataTypesSupport : uint8_t;
 
 /** Real-time access to table list and table structure from remote MySQL
  *  It doesn't make any manipulations with filesystem.

src/Dictionaries/IDictionary.h

@@ -37,7 +37,7 @@ using DictionaryHierarchicalParentToChildIndexPtr = std::shared_ptr<DictionaryHi
   *
   * Complex is for dictionaries that support any combination of key columns.
   */
-enum class DictionaryKeyType
+enum class DictionaryKeyType : uint8_t
 {
     Simple,
     Complex
@@ -46,7 +46,7 @@ enum class DictionaryKeyType
 /** DictionarySpecialKeyType provides IDictionary client information about
   * which special key type is supported by dictionary.
   */
-enum class DictionarySpecialKeyType
+enum class DictionarySpecialKeyType : uint8_t
 {
     None,
     Range

src/Dictionaries/PolygonDictionary.h

@@ -34,7 +34,7 @@ public:
      *      - A point is represented by its coordinates stored in an according structure (see below).
      *  A simple polygon is represented by an one-dimensional array of points, stored in the according structure.
      */
-    enum class InputType
+    enum class InputType : uint8_t
     {
         MultiPolygon,
         SimplePolygon
@@ -42,7 +42,7 @@ public:
     /** Controls the different types allowed for providing the coordinates of points.
       * Right now a point can be represented by either an array or a tuple of two Float64 values.
       */
-    enum class PointType
+    enum class PointType : uint8_t
     {
         Array,
         Tuple,

src/Disks/DiskEncryptedTransaction.h

@@ -12,7 +12,7 @@
 namespace DB
 {
 
-namespace FileEncryption { enum class Algorithm; }
+namespace FileEncryption { enum class Algorithm : uint8_t; }
 
 struct DiskEncryptedSettings
 {

src/Disks/DiskType.h

@@ -6,14 +6,14 @@
 namespace DB
 {
 
-enum class DataSourceType
+enum class DataSourceType : uint8_t
 {
     Local,
     RAM,
     ObjectStorage,
 };
 
-enum class ObjectStorageType
+enum class ObjectStorageType : uint8_t
 {
     None,
     S3,
@@ -23,7 +23,7 @@ enum class ObjectStorageType
     Local,
 };
 
-enum class MetadataStorageType
+enum class MetadataStorageType : uint8_t
 {
     None,
     Local,

src/Disks/IO/CachedOnDiskReadBufferFromFile.h

@@ -57,7 +57,7 @@ public:
 
     String getFileName() const override { return source_file_path; }
 
-    enum class ReadType
+    enum class ReadType : uint8_t
     {
         CACHED,
         REMOTE_FS_READ_BYPASS_CACHE,

src/Disks/IO/getThreadPoolReader.h

@@ -7,7 +7,7 @@ namespace DB
 
 class IAsynchronousReader;
 
-enum class FilesystemReaderType
+enum class FilesystemReaderType : uint8_t
 {
     SYNCHRONOUS_LOCAL_FS_READER,
     ASYNCHRONOUS_LOCAL_FS_READER,

src/Disks/IVolume.h

@@ -8,14 +8,14 @@
 namespace DB
 {
 
-enum class VolumeType
+enum class VolumeType : uint8_t
 {
     JBOD,
     SINGLE_DISK,
     UNKNOWN
 };
 
-enum class VolumeLoadBalancing
+enum class VolumeLoadBalancing : uint8_t
 {
     ROUND_ROBIN,
     LEAST_USED,

src/Disks/ObjectStorages/MetadataStorageTransactionState.h

@@ -4,7 +4,7 @@
 namespace DB
 {
 
-enum class MetadataStorageTransactionState
+enum class MetadataStorageTransactionState : uint8_t
 {
     PREPARING,
     FAILED,

src/Disks/ObjectStorages/Web/WebObjectStorage.h

@@ -98,7 +98,7 @@ protected:
     [[noreturn]] static void throwNotAllowed();
     bool exists(const std::string & path) const;
 
-    enum class FileType
+    enum class FileType : uint8_t
     {
         File,
         Directory

src/Disks/WriteMode.h

@@ -3,10 +3,8 @@
 namespace DB
 {
 
-/**
- * Mode of opening a file for write.
- */
-enum class WriteMode
+/// Mode of opening a file for write.
+enum class WriteMode : uint8_t
 {
     Rewrite,
     Append

src/Formats/BSONTypes.h

@@ -13,7 +13,7 @@ using BSONSizeT = uint32_t;
 static const BSONSizeT MAX_BSON_SIZE = std::numeric_limits<BSONSizeT>::max();
 
 /// See details on https://bsonspec.org/spec.html
-enum class BSONType
+enum class BSONType : uint8_t
 {
     DOUBLE = 0x01,
     STRING = 0x02,
@@ -38,7 +38,7 @@ enum class BSONType
     MAX_KEY = 0x7F,
 };
 
-enum class BSONBinarySubtype
+enum class BSONBinarySubtype : uint8_t
 {
     BINARY = 0x00,
     FUNCTION = 0x01,

src/Formats/FormatSettings.h

@@ -49,7 +49,7 @@ struct FormatSettings
     bool try_infer_datetimes = false;
     bool try_infer_exponent_floats = false;
 
-    enum class DateTimeInputFormat
+    enum class DateTimeInputFormat : uint8_t
     {
         Basic,        /// Default format for fast parsing: YYYY-MM-DD hh:mm:ss (ISO-8601 without fractional part and timezone) or NNNNNNNNNN unix timestamp.
         BestEffort,   /// Use sophisticated rules to parse whatever possible.
@@ -58,14 +58,14 @@ struct FormatSettings
 
     DateTimeInputFormat date_time_input_format = DateTimeInputFormat::Basic;
 
-    enum class DateTimeOutputFormat
+    enum class DateTimeOutputFormat : uint8_t
     {
         Simple,
         ISO,
         UnixTimestamp
     };
 
-    enum class EscapingRule
+    enum class EscapingRule : uint8_t
     {
         None,
         Escaped,
@@ -80,7 +80,7 @@ struct FormatSettings
 
     DateTimeOutputFormat date_time_output_format = DateTimeOutputFormat::Simple;
 
-    enum class IntervalOutputFormat
+    enum class IntervalOutputFormat : uint8_t
     {
         Kusto,
         Numeric
@@ -91,7 +91,7 @@ struct FormatSettings
         IntervalOutputFormat output_format = IntervalOutputFormat::Numeric;
     } interval{};
 
-    enum class DateTimeOverflowBehavior
+    enum class DateTimeOverflowBehavior : uint8_t
     {
         Ignore,
         Throw,
@@ -114,7 +114,7 @@ struct FormatSettings
 
     size_t max_threads = 1;
 
-    enum class ArrowCompression
+    enum class ArrowCompression : uint8_t
     {
         NONE,
         LZ4_FRAME,
@@ -232,7 +232,7 @@ struct FormatSettings
         String column_for_object_name{};
     } json_object_each_row{};
 
-    enum class ParquetVersion
+    enum class ParquetVersion : uint8_t
     {
         V1_0,
         V2_4,
@@ -240,7 +240,7 @@ struct FormatSettings
         V2_LATEST,
     };
 
-    enum class ParquetCompression
+    enum class ParquetCompression : uint8_t
     {
         NONE,
         SNAPPY,
@@ -285,7 +285,7 @@ struct FormatSettings
         bool output_format_pretty_row_numbers = false;
         UInt64 output_format_pretty_single_large_number_tip_threshold = 1'000'000;
 
-        enum class Charset
+        enum class Charset : uint8_t
         {
             UTF8,
             ASCII,
@@ -372,7 +372,7 @@ struct FormatSettings
         bool escape_quote_with_quote = false;
     } values{};
 
-    enum class ORCCompression
+    enum class ORCCompression : uint8_t
     {
         NONE,
         LZ4,
@@ -397,7 +397,7 @@ struct FormatSettings
 
     /// For capnProto format we should determine how to
     /// compare ClickHouse Enum and Enum from schema.
-    enum class CapnProtoEnumComparingMode
+    enum class CapnProtoEnumComparingMode : uint8_t
     {
         BY_NAMES, // Names in enums should be the same, values can be different.
         BY_NAMES_CASE_INSENSITIVE, // Case-insensitive name comparison.
@@ -411,7 +411,7 @@ struct FormatSettings
         bool use_autogenerated_schema = true;
     } capn_proto{};
 
-    enum class MsgPackUUIDRepresentation
+    enum class MsgPackUUIDRepresentation : uint8_t
     {
         STR, // Output UUID as a string of 36 characters.
         BIN, // Output UUID as 16-bytes binary.