YT-18571: Refactor YT enums to make them Arcadia-friendly

5 files changed, 258 insertions, 234 deletions

diff --git a/library/cpp/yt/misc/enum-inl.h b/library/cpp/yt/misc/enum-inl.h
index 18a78621a9..ba33290e79 100644
--- a/library/cpp/yt/misc/enum-inl.h
+++ b/library/cpp/yt/misc/enum-inl.h
@@ -15,8 +15,8 @@ namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#define ENUM__CLASS(name, underlyingType, seq) \
-    enum class name : underlyingType \
+#define ENUM__CLASS(enumType, underlyingType, seq) \
+    enum class enumType : underlyingType \
     { \
         PP_FOR_EACH(ENUM__DOMAIN_ITEM, seq) \
     };
@@ -39,10 +39,27 @@ namespace NYT {
 namespace NDetail {
 
 template <typename TValues>
-static constexpr bool AreValuesDistinct(const TValues& values)
+constexpr bool CheckValuesMonotonic(const TValues& values)
 {
-    for (int i = 0; i < static_cast<int>(values.size()); ++i) {
-        for (int j = i + 1; j < static_cast<int>(values.size()); ++j) {
+    if (std::size(values) <= 1) {
+        return true;
+    }
+    for (size_t i = 0; i < std::size(values) - 1; ++i) {
+        if (values[i] > values[i + 1]) {
+            return false;
+        }
+    }
+    return true;
+}
+
+template <typename TValues>
+constexpr bool CheckValuesUnique(const TValues& values)
+{
+    if (CheckValuesMonotonic(values)) {
+        return true;
+    }
+    for (size_t i = 0; i < std::size(values); ++i) {
+        for (size_t j = i + 1; j < std::size(values); ++j) {
             if (values[i] == values[j]) {
                 return false;
             }
@@ -55,68 +72,61 @@ static constexpr bool AreValuesDistinct(const TValues& values)
 
 ////////////////////////////////////////////////////////////////////////////////
 
-#define ENUM__BEGIN_TRAITS(name, underlyingType, isBit, isStringSerializable, seq) \
-    struct TEnumTraitsImpl_##name \
+#define ENUM__BEGIN_TRAITS(enumType, underlyingType, isBit, isStringSerializable, seq) \
+    struct TEnumTraitsImpl_##enumType \
     { \
-        using TType = name; \
-        using TUnderlying = underlyingType; \
+        using T = enumType; \
+        \
         [[maybe_unused]] static constexpr bool IsBitEnum = isBit; \
         [[maybe_unused]] static constexpr bool IsStringSerializableEnum = isStringSerializable; \
-        [[maybe_unused]] static constexpr int DomainSize = PP_COUNT(seq); \
+        static constexpr int DomainSize = PP_COUNT(seq); \
+        \
+        static constexpr int GetDomainSize() \
+        { \
+            return DomainSize; \
+        } \
         \
         static constexpr std::array<TStringBuf, DomainSize> Names{{ \
             PP_FOR_EACH(ENUM__GET_DOMAIN_NAMES_ITEM, seq) \
         }}; \
-        static constexpr std::array<TType, DomainSize> Values{{ \
+        static constexpr std::array<T, DomainSize> Values{{ \
             PP_FOR_EACH(ENUM__GET_DOMAIN_VALUES_ITEM, seq) \
         }}; \
         \
         static TStringBuf GetTypeName() \
         { \
-            static constexpr TStringBuf typeName = PP_STRINGIZE(name); \
-            return typeName; \
+            static constexpr TStringBuf Result = PP_STRINGIZE(enumType); \
+            return Result; \
         } \
         \
-        static const TStringBuf* FindLiteralByValue(TType value) \
+        static const std::optional<TStringBuf> FindLiteralByValue(T value) \
         { \
-            for (int i = 0; i < DomainSize; ++i) { \
+            for (int i = 0; i < GetDomainSize(); ++i) { \
                 if (Values[i] == value) { \
-                    return &Names[i]; \
+                    return Names[i]; \
                 } \
             } \
-            return nullptr; \
+            return std::nullopt; \
         } \
         \
-        static bool FindValueByLiteral(TStringBuf literal, TType* result) \
+        static std::optional<T> FindValueByLiteral(TStringBuf literal) \
         { \
-            for (int i = 0; i < DomainSize; ++i) { \
+            for (int i = 0; i < GetDomainSize(); ++i) { \
                 if (Names[i] == literal) { \
-                    *result = Values[i]; \
-                    return true; \
+                    return Values[i]; \
                 } \
             } \
-            return false; \
+            return std::nullopt; \
         } \
         \
-        static const std::array<TStringBuf, DomainSize>& GetDomainNames() \
+        static constexpr const std::array<TStringBuf, DomainSize>& GetDomainNames() \
         { \
             return Names; \
         } \
         \
-        static const std::array<TType, DomainSize>& GetDomainValues() \
+        static constexpr const std::array<T, DomainSize>& GetDomainValues() \
         { \
             return Values; \
-        } \
-        \
-        static TType FromString(TStringBuf str) \
-        { \
-            TType value; \
-            if (!FindValueByLiteral(str, &value)) { \
-                throw ::NYT::TSimpleException(Sprintf("Error parsing %s value %s", \
-                    PP_STRINGIZE(name), \
-                    TString(str).Quote().c_str()).c_str()); \
-            } \
-            return value; \
         }
 
 #define ENUM__GET_DOMAIN_VALUES_ITEM(item) \
@@ -130,7 +140,7 @@ static constexpr bool AreValuesDistinct(const TValues& values)
     ENUM__GET_DOMAIN_VALUES_ITEM_ATOMIC(PP_ELEMENT(seq, 0))
 
 #define ENUM__GET_DOMAIN_VALUES_ITEM_ATOMIC(item) \
-    TType::item,
+    T::item,
 
 #define ENUM__GET_DOMAIN_NAMES_ITEM(item) \
     PP_IF( \
@@ -161,119 +171,120 @@ static constexpr bool AreValuesDistinct(const TValues& values)
 #define ENUM__GET_DOMAIN_NAMES_ITEM_ATOMIC(item) \
     TStringBuf(PP_STRINGIZE(item)),
 
-#define ENUM__DECOMPOSE \
-    static std::vector<TType> Decompose(TType value) \
-    { \
-        std::vector<TType> result; \
-        for (int i = 0; i < DomainSize; ++i) { \
-            if (static_cast<TUnderlying>(value) & static_cast<TUnderlying>(Values[i])) { \
-                result.push_back(Values[i]); \
-            } \
-        } \
-        return result; \
-    }
+#define ENUM__VALIDATE_UNIQUE(enumType) \
+    static_assert(::NYT::NDetail::CheckValuesUnique(Values), \
+        "Enumeration " #enumType " contains duplicate values");
 
-#define ENUM__MINMAX \
-    static constexpr TType GetMinValue() \
-    { \
-        static_assert(!Values.empty()); \
-        return *std::min_element(std::begin(Values), std::end(Values)); \
-    } \
-    \
-    static constexpr TType GetMaxValue() \
-    { \
-        static_assert(!Values.empty()); \
-        return *std::max_element(std::begin(Values), std::end(Values)); \
-    }
-
-#define ENUM__VALIDATE_UNIQUE(name) \
-    static_assert(::NYT::NDetail::AreValuesDistinct(Values), \
-        "Enumeration " #name " contains duplicate values");
-
-#define ENUM__END_TRAITS(name) \
+#define ENUM__END_TRAITS(enumType) \
     }; \
     \
-    [[maybe_unused]] inline TEnumTraitsImpl_##name GetEnumTraitsImpl(name) \
+    [[maybe_unused]] inline TEnumTraitsImpl_##enumType GetEnumTraitsImpl(enumType) \
     { \
-        return TEnumTraitsImpl_##name(); \
+        return {}; \
     } \
     \
     using ::ToString; \
-    [[maybe_unused]] inline TString ToString(name value) \
+    [[maybe_unused]] inline TString ToString(enumType value) \
     { \
-        return ::NYT::TEnumTraits<name>::ToString(value); \
+        return ::NYT::TEnumTraits<enumType>::ToString(value); \
     }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 template <class T>
-std::vector<T> TEnumTraits<T, true>::Decompose(T value)
+constexpr int TEnumTraitsWithKnownDomain<T, true>::GetDomainSize()
 {
-    return TImpl::Decompose(value);
+    return TEnumTraitsImpl<T>::GetDomainSize();
 }
 
 template <class T>
-T TEnumTraits<T, true>::FromString(TStringBuf str)
+constexpr auto TEnumTraitsWithKnownDomain<T, true>::GetDomainNames() -> const std::array<TStringBuf, GetDomainSize()>&
 {
-    return TImpl::FromString(str);
+    return TEnumTraitsImpl<T>::GetDomainNames();
 }
 
 template <class T>
-TString TEnumTraits<T, true>::ToString(TType value)
+constexpr auto TEnumTraitsWithKnownDomain<T, true>::GetDomainValues() -> const std::array<T, GetDomainSize()>&
 {
-    TString result;
-    const auto* literal = FindLiteralByValue(value);
-    if (literal) {
-        result = *literal;
-    } else {
-        result = GetTypeName();
-        result += "(";
-        result += ::ToString(static_cast<TUnderlying>(value));
-        result += ")";
-    }
-    return result;
+    return TEnumTraitsImpl<T>::GetDomainValues();
 }
 
 template <class T>
-auto TEnumTraits<T, true>::GetDomainValues() -> const std::array<T, DomainSize>&
+constexpr T TEnumTraitsWithKnownDomain<T, true>::GetMinValue()
+    requires (!TEnumTraitsImpl<T>::IsBitEnum)
 {
-    return TImpl::GetDomainValues();
+    const auto& values = GetDomainValues();
+    static_assert(!values.empty()); \
+    return *std::min_element(std::begin(values), std::end(values));
 }
 
 template <class T>
-auto TEnumTraits<T, true>::GetDomainNames() -> const std::array<TStringBuf, DomainSize>&
+constexpr T TEnumTraitsWithKnownDomain<T, true>::GetMaxValue()
+    requires (!TEnumTraitsImpl<T>::IsBitEnum)
 {
-    return TImpl::GetDomainNames();
+    const auto& values = GetDomainValues();
+    static_assert(!values.empty()); \
+    return *std::max_element(std::begin(values), std::end(values));
+}
+
+template <class T>
+std::vector<T> TEnumTraitsWithKnownDomain<T, true>::Decompose(T value)
+    requires (TEnumTraitsImpl<T>::IsBitEnum)
+{
+    std::vector<T> result;
+    for (auto domainValue : GetDomainValues()) {
+        if (Any(value & domainValue)) {
+            result.push_back(domainValue);
+        }
+    }
+    return result;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+
 template <class T>
-constexpr T TEnumTraits<T, true>::GetMaxValue()
+TStringBuf TEnumTraits<T, true>::GetTypeName()
 {
-    return TImpl::GetMaxValue();
+    return TEnumTraitsImpl<T>::GetTypeName();
 }
 
 template <class T>
-constexpr T TEnumTraits<T, true>::GetMinValue()
+std::optional<T> TEnumTraits<T, true>::FindValueByLiteral(TStringBuf literal)
 {
-    return TImpl::GetMinValue();
+    return TEnumTraitsImpl<T>::FindValueByLiteral(literal);
 }
 
 template <class T>
-bool TEnumTraits<T, true>::FindValueByLiteral(TStringBuf literal, TType* result)
+std::optional<TStringBuf> TEnumTraits<T, true>::FindLiteralByValue(T value)
 {
-    return TImpl::FindValueByLiteral(literal, result);
+    return TEnumTraitsImpl<T>::FindLiteralByValue(value);
 }
 
 template <class T>
-const TStringBuf* TEnumTraits<T, true>::FindLiteralByValue(TType value)
+TString TEnumTraits<T, true>::ToString(T value)
 {
-    return TImpl::FindLiteralByValue(value);
+    using ::ToString;
+    if (auto optionalLiteral = TEnumTraits<T>::FindLiteralByValue(value)) {
+        return ToString(*optionalLiteral);
+    }
+    TString result;
+    result = TEnumTraits<T>::GetTypeName();
+    result += "(";
+    result += ToString(ToUnderlying(value));
+    result += ")";
+    return result;
 }
 
 template <class T>
-TStringBuf TEnumTraits<T, true>::GetTypeName()
+T TEnumTraits<T, true>::FromString(TStringBuf literal)
 {
-    return TImpl::GetTypeName();
+    auto optionalValue = FindValueByLiteral(literal);
+    if (!optionalValue) {
+        throw ::NYT::TSimpleException(Sprintf("Error parsing %s value %s",
+            GetTypeName().data(),
+            TString(literal).Quote().c_str()).c_str());
+    }
+    return *optionalValue;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -298,7 +309,7 @@ template <class E, class T, E Min, E Max>
 T& TEnumIndexedVector<E, T, Min, Max>::operator[] (E index)
 {
     Y_ASSERT(index >= Min && index <= Max);
-    return Items_[static_cast<TUnderlying>(index) - static_cast<TUnderlying>(Min)];
+    return Items_[ToUnderlying(index) - ToUnderlying(Min)];
 }
 
 template <class E, class T, E Min, E Max>
@@ -342,58 +353,62 @@ bool TEnumIndexedVector<E, T, Min, Max>::IsDomainValue(E value)
 #define ENUM__BINARY_BITWISE_OPERATOR(T, assignOp, op) \
     [[maybe_unused]] inline constexpr T operator op (T lhs, T rhs) \
     { \
-        using TUnderlying = typename TEnumTraits<T>::TUnderlying; \
-        return T(static_cast<TUnderlying>(lhs) op static_cast<TUnderlying>(rhs)); \
+        return T(ToUnderlying(lhs) op ToUnderlying(rhs)); \
     } \
     \
     [[maybe_unused]] inline T& operator assignOp (T& lhs, T rhs) \
     { \
-        using TUnderlying = typename TEnumTraits<T>::TUnderlying; \
-        lhs = T(static_cast<TUnderlying>(lhs) op static_cast<TUnderlying>(rhs)); \
+        lhs = T(ToUnderlying(lhs) op ToUnderlying(rhs)); \
         return lhs; \
     }
 
 #define ENUM__UNARY_BITWISE_OPERATOR(T, op) \
     [[maybe_unused]] inline constexpr T operator op (T value) \
     { \
-        using TUnderlying = typename TEnumTraits<T>::TUnderlying; \
-        return T(op static_cast<TUnderlying>(value)); \
+        return T(op ToUnderlying(value)); \
     }
 
 #define ENUM__BIT_SHIFT_OPERATOR(T, assignOp, op) \
     [[maybe_unused]] inline constexpr T operator op (T lhs, size_t rhs) \
     { \
-        using TUnderlying = typename TEnumTraits<T>::TUnderlying; \
-        return T(static_cast<TUnderlying>(lhs) op rhs); \
+        return T(ToUnderlying(lhs) op rhs); \
     } \
     \
     [[maybe_unused]] inline T& operator assignOp (T& lhs, size_t rhs) \
     { \
-        using TUnderlying = typename TEnumTraits<T>::TUnderlying; \
-        lhs = T(static_cast<TUnderlying>(lhs) op rhs); \
+        lhs = T(ToUnderlying(lhs) op rhs); \
         return lhs; \
     }
 
-#define ENUM__BITWISE_OPS(name) \
-    ENUM__BINARY_BITWISE_OPERATOR(name, &=, &)  \
-    ENUM__BINARY_BITWISE_OPERATOR(name, |=, | ) \
-    ENUM__BINARY_BITWISE_OPERATOR(name, ^=, ^)  \
-    ENUM__UNARY_BITWISE_OPERATOR(name, ~)       \
-    ENUM__BIT_SHIFT_OPERATOR(name, <<=, << )    \
-    ENUM__BIT_SHIFT_OPERATOR(name, >>=, >> )
+#define ENUM__BITWISE_OPS(enumType) \
+    ENUM__BINARY_BITWISE_OPERATOR(enumType, &=, &)  \
+    ENUM__BINARY_BITWISE_OPERATOR(enumType, |=, | ) \
+    ENUM__BINARY_BITWISE_OPERATOR(enumType, ^=, ^)  \
+    ENUM__UNARY_BITWISE_OPERATOR(enumType, ~)       \
+    ENUM__BIT_SHIFT_OPERATOR(enumType, <<=, << )    \
+    ENUM__BIT_SHIFT_OPERATOR(enumType, >>=, >> )
 
 ////////////////////////////////////////////////////////////////////////////////
 
-template <typename E, typename>
-bool Any(E value)
+template <typename E>
+    requires std::is_enum_v<E>
+constexpr std::underlying_type_t<E> ToUnderlying(E value) noexcept
+{
+    return static_cast<std::underlying_type_t<E>>(value);
+}
+
+template <typename E>
+    requires TEnumTraits<E>::IsBitEnum
+constexpr bool Any(E value) noexcept
 {
-    return static_cast<typename TEnumTraits<E>::TUnderlying>(value) != 0;
+    return ToUnderlying(value) != 0;
 }
 
-template <class E, typename>
-bool None(E value)
+template <typename E>
+    requires TEnumTraits<E>::IsBitEnum
+constexpr bool None(E value) noexcept
 {
-    return static_cast<typename TEnumTraits<E>::TUnderlying>(value) == 0;
+    return ToUnderlying(value) == 0;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/library/cpp/yt/misc/enum.h b/library/cpp/yt/misc/enum.h
index 1353900996..773e1ac4ed 100644
--- a/library/cpp/yt/misc/enum.h
+++ b/library/cpp/yt/misc/enum.h
@@ -4,9 +4,9 @@
 
 #include <util/generic/strbuf.h>
 
-#include <stdexcept>
-#include <type_traits>
 #include <array>
+#include <optional>
+#include <type_traits>
 #include <vector>
 
 #include <library/cpp/yt/exception/exception.h>
@@ -22,15 +22,33 @@ namespace NYT {
  * (unittests/enum_ut.cpp).
  */
 
-// Actual overload must be provided with defines DEFINE_ENUM_XXX (see below).
+// The actual overload must be provided with DEFINE_ENUM* (see below).
 template <class T>
 void GetEnumTraitsImpl(T);
 
+template <class T>
+using TEnumTraitsImpl = decltype(GetEnumTraitsImpl(T()));
+
+template <class T>
+constexpr bool IsEnumDomainSizeKnown()
+{
+    if constexpr(requires{ TEnumTraitsImpl<T>::DomainSize; }) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
 template <
     class T,
-    bool = std::is_enum<T>::value &&
-        !std::is_convertible<T, int>::value &&
-        !std::is_same<void, decltype(GetEnumTraitsImpl(T()))>::value
+    bool = IsEnumDomainSizeKnown<T>()
+>
+struct TEnumTraitsWithKnownDomain
+{ };
+
+template <
+    class T,
+    bool = std::is_enum_v<T> && !std::is_same_v<TEnumTraitsImpl<T>, void>
 >
 struct TEnumTraits
 {
@@ -40,124 +58,122 @@ struct TEnumTraits
 };
 
 template <class T>
-struct TEnumTraits<T, true>
+struct TEnumTraitsWithKnownDomain<T, true>
 {
-    using TImpl = decltype(GetEnumTraitsImpl(T()));
-    using TType = T;
-    using TUnderlying = typename TImpl::TUnderlying;
-
-    static constexpr bool IsEnum = true;
-    static constexpr bool IsBitEnum = TImpl::IsBitEnum;
-    static constexpr bool IsStringSerializableEnum = TImpl::IsStringSerializableEnum;
+    static constexpr int GetDomainSize();
 
-    static constexpr int DomainSize = TImpl::DomainSize;
+    static constexpr const std::array<TStringBuf, GetDomainSize()>& GetDomainNames();
+    static constexpr const std::array<T, GetDomainSize()>& GetDomainValues();
 
-    static TStringBuf GetTypeName();
+    // For non-bit enums only.
+    static constexpr T GetMinValue()
+        requires (!TEnumTraitsImpl<T>::IsBitEnum);
+    static constexpr T GetMaxValue()
+        requires (!TEnumTraitsImpl<T>::IsBitEnum);
 
-    static const TStringBuf* FindLiteralByValue(TType value);
-    static bool FindValueByLiteral(TStringBuf literal, TType* result);
+    // For bit enums only.
+    static std::vector<T> Decompose(T value)
+        requires (TEnumTraitsImpl<T>::IsBitEnum);
+};
 
-    static const std::array<TStringBuf, DomainSize>& GetDomainNames();
-    static const std::array<TType, DomainSize>& GetDomainValues();
+template <class T>
+struct TEnumTraits<T, true>
+    : public TEnumTraitsWithKnownDomain<T>
+{
+    static constexpr bool IsEnum = true;
+    static constexpr bool IsBitEnum = TEnumTraitsImpl<T>::IsBitEnum;
+    static constexpr bool IsStringSerializableEnum = TEnumTraitsImpl<T>::IsStringSerializableEnum;
 
-    static TType FromString(TStringBuf str);
-    static TString ToString(TType value);
+    static TStringBuf GetTypeName();
 
-    // For non-bit enums only.
-    static constexpr TType GetMinValue();
-    static constexpr TType GetMaxValue();
+    static std::optional<TStringBuf> FindLiteralByValue(T value);
+    static std::optional<T> FindValueByLiteral(TStringBuf literal);
 
-    // For bit enums only.
-    static std::vector<TType> Decompose(TType value);
+    static TString ToString(T value);
+    static T FromString(TStringBuf literal);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
 //! Defines a smart enumeration with a specific underlying type.
 /*!
- * \param name Enumeration name.
+ * \param enumType Enumeration enumType.
  * \param seq Enumeration domain encoded as a <em>sequence</em>.
  * \param underlyingType Underlying type.
  */
-#define DEFINE_ENUM_WITH_UNDERLYING_TYPE(name, underlyingType, seq) \
-    ENUM__CLASS(name, underlyingType, seq) \
-    ENUM__BEGIN_TRAITS(name, underlyingType, false, false, seq) \
-    ENUM__MINMAX \
-    ENUM__VALIDATE_UNIQUE(name) \
-    ENUM__END_TRAITS(name)
+#define DEFINE_ENUM_WITH_UNDERLYING_TYPE(enumType, underlyingType, seq) \
+    ENUM__CLASS(enumType, underlyingType, seq) \
+    ENUM__BEGIN_TRAITS(enumType, underlyingType, false, false, seq) \
+    ENUM__VALIDATE_UNIQUE(enumType) \
+    ENUM__END_TRAITS(enumType)
 
 //! Defines a smart enumeration with a specific underlying type.
 //! Duplicate enumeration values are allowed.
-#define DEFINE_AMBIGUOUS_ENUM_WITH_UNDERLYING_TYPE(name, underlyingType, seq) \
-    ENUM__CLASS(name, underlyingType, seq) \
-    ENUM__BEGIN_TRAITS(name, underlyingType, false, false, seq) \
-    ENUM__MINMAX \
-    ENUM__END_TRAITS(name)
+#define DEFINE_AMBIGUOUS_ENUM_WITH_UNDERLYING_TYPE(enumType, underlyingType, seq) \
+    ENUM__CLASS(enumType, underlyingType, seq) \
+    ENUM__BEGIN_TRAITS(enumType, underlyingType, false, false, seq) \
+    ENUM__END_TRAITS(enumType)
 
 //! Defines a smart enumeration with the default |int| underlying type.
-#define DEFINE_ENUM(name, seq) \
-    DEFINE_ENUM_WITH_UNDERLYING_TYPE(name, int, seq)
+#define DEFINE_ENUM(enumType, seq) \
+    DEFINE_ENUM_WITH_UNDERLYING_TYPE(enumType, int, seq)
 
 //! Defines a smart enumeration with a specific underlying type.
 /*!
- * \param name Enumeration name.
+ * \param enumType Enumeration enumType.
  * \param seq Enumeration domain encoded as a <em>sequence</em>.
  * \param underlyingType Underlying type.
  */
-#define DEFINE_BIT_ENUM_WITH_UNDERLYING_TYPE(name, underlyingType, seq) \
-    ENUM__CLASS(name, underlyingType, seq) \
-    ENUM__BEGIN_TRAITS(name, underlyingType, true, false, seq) \
-    ENUM__DECOMPOSE \
-    ENUM__VALIDATE_UNIQUE(name) \
-    ENUM__END_TRAITS(name) \
-    ENUM__BITWISE_OPS(name)
+#define DEFINE_BIT_ENUM_WITH_UNDERLYING_TYPE(enumType, underlyingType, seq) \
+    ENUM__CLASS(enumType, underlyingType, seq) \
+    ENUM__BEGIN_TRAITS(enumType, underlyingType, true, false, seq) \
+    ENUM__VALIDATE_UNIQUE(enumType) \
+    ENUM__END_TRAITS(enumType) \
+    ENUM__BITWISE_OPS(enumType)
 
 //! Defines a smart enumeration with a specific underlying type.
 //! Duplicate enumeration values are allowed.
 /*!
- * \param name Enumeration name.
+ * \param enumType Enumeration enumType.
  * \param seq Enumeration domain encoded as a <em>sequence</em>.
  * \param underlyingType Underlying type.
  */
-#define DEFINE_AMBIGUOUS_BIT_ENUM_WITH_UNDERLYING_TYPE(name, underlyingType, seq) \
-    ENUM__CLASS(name, underlyingType, seq) \
-    ENUM__BEGIN_TRAITS(name, underlyingType, true, false, seq) \
-    ENUM__DECOMPOSE \
-    ENUM__END_TRAITS(name) \
-    ENUM__BITWISE_OPS(name)
-
-//! Defines a smart enumeration with the default |unsigned| underlying type.
+#define DEFINE_AMBIGUOUS_BIT_ENUM_WITH_UNDERLYING_TYPE(enumType, underlyingType, seq) \
+    ENUM__CLASS(enumType, underlyingType, seq) \
+    ENUM__BEGIN_TRAITS(enumType, underlyingType, true, false, seq) \
+    ENUM__END_TRAITS(enumType) \
+    ENUM__BITWISE_OPS(enumType)
+
+//! Defines a smart enumeration with the default |unsigned int| underlying type.
 /*!
- * \param name Enumeration name.
+ * \param enumType Enumeration enumType.
  * \param seq Enumeration domain encoded as a <em>sequence</em>.
  */
-#define DEFINE_BIT_ENUM(name, seq) \
-    DEFINE_BIT_ENUM_WITH_UNDERLYING_TYPE(name, unsigned, seq)
+#define DEFINE_BIT_ENUM(enumType, seq) \
+    DEFINE_BIT_ENUM_WITH_UNDERLYING_TYPE(enumType, unsigned int, seq)
 
 //! Defines a smart enumeration with a specific underlying type and IsStringSerializable attribute.
 /*!
- * \param name Enumeration name.
+ * \param enumType Enumeration enumType.
  * \param seq Enumeration domain encoded as a <em>sequence</em>.
  * \param underlyingType Underlying type.
  */
-#define DEFINE_STRING_SERIALIZABLE_ENUM_WITH_UNDERLYING_TYPE(name, underlyingType, seq) \
-    ENUM__CLASS(name, underlyingType, seq) \
-    ENUM__BEGIN_TRAITS(name, underlyingType, false, true, seq) \
-    ENUM__MINMAX \
-    ENUM__VALIDATE_UNIQUE(name) \
-    ENUM__END_TRAITS(name) \
+#define DEFINE_STRING_SERIALIZABLE_ENUM_WITH_UNDERLYING_TYPE(enumType, underlyingType, seq) \
+    ENUM__CLASS(enumType, underlyingType, seq) \
+    ENUM__BEGIN_TRAITS(enumType, underlyingType, false, true, seq) \
+    ENUM__VALIDATE_UNIQUE(enumType) \
+    ENUM__END_TRAITS(enumType) \
 
 //! Defines a smart enumeration with a specific underlying type and IsStringSerializable attribute.
 //! Duplicate enumeration values are allowed.
-#define DEFINE_AMBIGUOUS_STRING_SERIALIZABLE_ENUM_WITH_UNDERLYING_TYPE(name, underlyingType, seq) \
-    ENUM__CLASS(name, underlyingType, seq) \
-    ENUM__BEGIN_TRAITS(name, underlyingType, false, true, seq) \
-    ENUM__MINMAX \
-    ENUM__END_TRAITS(name)
+#define DEFINE_AMBIGUOUS_STRING_SERIALIZABLE_ENUM_WITH_UNDERLYING_TYPE(enumType, underlyingType, seq) \
+    ENUM__CLASS(enumType, underlyingType, seq) \
+    ENUM__BEGIN_TRAITS(enumType, underlyingType, false, true, seq) \
+    ENUM__END_TRAITS(enumType)
 
 //! Defines a smart enumeration with the default |int| underlying type and IsStringSerializable attribute.
-#define DEFINE_STRING_SERIALIZABLE_ENUM(name, seq) \
-    DEFINE_STRING_SERIALIZABLE_ENUM_WITH_UNDERLYING_TYPE(name, int, seq)
+#define DEFINE_STRING_SERIALIZABLE_ENUM(enumType, seq) \
+    DEFINE_STRING_SERIALIZABLE_ENUM_WITH_UNDERLYING_TYPE(enumType, int, seq)
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -199,20 +215,27 @@ public:
     static bool IsDomainValue(E value);
 
 private:
-    using TUnderlying = typename TEnumTraits<E>::TUnderlying;
+    using TUnderlying = std::underlying_type_t<E>;
     static constexpr int N = static_cast<TUnderlying>(Max) - static_cast<TUnderlying>(Min) + 1;
     std::array<T, N> Items_;
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
+//! Replace with |std::to_underlying| in C++23.
+template <typename E>
+    requires std::is_enum_v<E>
+constexpr std::underlying_type_t<E> ToUnderlying(E value) noexcept;
+
 //! Returns |true| iff the enumeration value is not bitwise zero.
-template <typename E, typename = std::enable_if_t<NYT::TEnumTraits<E>::IsBitEnum, E>>
-bool Any(E value);
+template <typename E>
+    requires TEnumTraits<E>::IsBitEnum
+constexpr bool Any(E value) noexcept;
 
 //! Returns |true| iff the enumeration value is bitwise zero.
-template <typename E, typename = std::enable_if_t<NYT::TEnumTraits<E>::IsBitEnum, E>>
-bool None(E value);
+template <typename E>
+    requires TEnumTraits<E>::IsBitEnum
+constexpr bool None(E value) noexcept;
 
 ////////////////////////////////////////////////////////////////////////////////
 
diff --git a/library/cpp/yt/misc/unittests/enum_ut.cpp b/library/cpp/yt/misc/unittests/enum_ut.cpp
index 2a024be228..1b1b6d0be2 100644
--- a/library/cpp/yt/misc/unittests/enum_ut.cpp
+++ b/library/cpp/yt/misc/unittests/enum_ut.cpp
@@ -52,7 +52,7 @@ std::vector<T> ToVector(std::array<T, N> array)
 
 TEST(TEnumTest, Domain)
 {
-    EXPECT_EQ(3, TEnumTraits<ESimple>::DomainSize);
+    EXPECT_EQ(3, TEnumTraits<ESimple>::GetDomainSize());
     std::vector<ESimple> v {
         ESimple::X,
         ESimple::Y,
@@ -101,16 +101,8 @@ TEST(TEnumTest, FromString)
 
     EXPECT_THROW(TEnumTraits<EColor>::FromString("Pink"), std::exception);
 
-    EColor color;
-    bool returnValue;
-
-    returnValue = TEnumTraits<EColor>::FindValueByLiteral("Red", &color);
-    EXPECT_EQ(EColor::Red, color);
-    EXPECT_TRUE(returnValue);
-
-    returnValue = TEnumTraits<EColor>::FindValueByLiteral("Pink", &color);
-    EXPECT_EQ(EColor::Red, color);
-    EXPECT_FALSE(returnValue);
+    EXPECT_EQ(EColor::Red, TEnumTraits<EColor>::FindValueByLiteral("Red"));
+    EXPECT_EQ(std::nullopt, TEnumTraits<EColor>::FindValueByLiteral("Pink"));
 }
 
 TEST(TEnumTest, Ordering)
@@ -182,8 +174,8 @@ TEST(TEnumTest, OrderingWithDomainValues)
 
 TEST(TEnumTest, DomainSize)
 {
-    EXPECT_EQ(3, TEnumTraits<ESimple>::DomainSize);
-    EXPECT_EQ(5, TEnumTraits<EColor>::DomainSize);
+    EXPECT_EQ(3, TEnumTraits<ESimple>::GetDomainSize());
+    EXPECT_EQ(5, TEnumTraits<EColor>::GetDomainSize());
 }
 
 TEST(TEnumTest, DomainValues)
diff --git a/library/cpp/yt/string/enum-inl.h b/library/cpp/yt/string/enum-inl.h
index 7ce7d2a350..7e6785efb4 100644
--- a/library/cpp/yt/string/enum-inl.h
+++ b/library/cpp/yt/string/enum-inl.h
@@ -27,14 +27,8 @@ void FormatUnknownEnumValue(
 template <class T>
 std::optional<T> TryParseEnum(TStringBuf value)
 {
-    static_assert(TEnumTraits<T>::IsEnum);
-
     auto tryFromString = [] (TStringBuf value) -> std::optional<T> {
-        T result;
-        if (auto ok = TEnumTraits<T>::FindValueByLiteral(DecodeEnumValue(value), &result)) {
-            return result;
-        }
-        return {};
+        return TEnumTraits<T>::FindValueByLiteral(DecodeEnumValue(value));
     };
 
     if constexpr (TEnumTraits<T>::IsBitEnum) {
@@ -65,28 +59,25 @@ T ParseEnum(TStringBuf value)
 template <class T>
 void FormatEnum(TStringBuilderBase* builder, T value, bool lowerCase)
 {
-    static_assert(TEnumTraits<T>::IsEnum);
-
     auto formatScalarValue = [builder, lowerCase] (T value) {
-        auto* literal = TEnumTraits<T>::FindLiteralByValue(value);
-        if (!literal) {
-            YT_VERIFY(!TEnumTraits<T>::IsBitEnum);
+        auto optionalLiteral = TEnumTraits<T>::FindLiteralByValue(value);
+        if (!optionalLiteral) {
             NYT::NDetail::FormatUnknownEnumValue(
                 builder,
                 TEnumTraits<T>::GetTypeName(),
-                static_cast<typename TEnumTraits<T>::TUnderlying>(value));
+                ToUnderlying(value));
             return;
         }
 
         if (lowerCase) {
-            CamelCaseToUnderscoreCase(builder, *literal);
+            CamelCaseToUnderscoreCase(builder, *optionalLiteral);
         } else {
-            builder->AppendString(*literal);
+            builder->AppendString(*optionalLiteral);
         }
     };
 
     if constexpr (TEnumTraits<T>::IsBitEnum) {
-        if (auto* literal = TEnumTraits<T>::FindLiteralByValue(value)) {
+        if (TEnumTraits<T>::FindLiteralByValue(value)) {
             formatScalarValue(value);
             return;
         }
@@ -106,7 +97,7 @@ void FormatEnum(TStringBuilderBase* builder, T value, bool lowerCase)
 }
 
 template <class T>
-TString FormatEnum(T value, typename TEnumTraits<T>::TType*)
+TString FormatEnum(T value)
 {
     TStringBuilder builder;
     FormatEnum(&builder, value, /*lowerCase*/ true);
diff --git a/library/cpp/yt/string/enum.h b/library/cpp/yt/string/enum.h
index 10dc02610f..caad6f2064 100644
--- a/library/cpp/yt/string/enum.h
+++ b/library/cpp/yt/string/enum.h
@@ -14,13 +14,16 @@ TString DecodeEnumValue(TStringBuf value);
 TString EncodeEnumValue(TStringBuf value);
 
 template <class T>
+std::optional<T> TryParseEnum(TStringBuf value);
+
+template <class T>
 T ParseEnum(TStringBuf value);
 
 template <class T>
 void FormatEnum(TStringBuilderBase* builder, T value, bool lowerCase);
 
 template <class T>
-TString FormatEnum(T value, typename TEnumTraits<T>::TType* = nullptr);
+TString FormatEnum(T value);
 
 ////////////////////////////////////////////////////////////////////////////////