Merge pull request #28659 from myrrc/improvement/tostring_to_magic_enum

Improving CH type system with concepts

.gitmodules

@@ -246,3 +246,6 @@
 [submodule "contrib/bzip2"]
 	path = contrib/bzip2
 	url = https://github.com/ClickHouse-Extras/bzip2.git
+[submodule "contrib/magic_enum"]
+	path = contrib/magic_enum
+	url = https://github.com/Neargye/magic_enum

base/common/CMakeLists.txt

@@ -85,6 +85,7 @@ target_link_libraries (common
         replxx
         cctz
         fmt
+        magic_enum
 )
 
 if (ENABLE_TESTS)

base/common/Decimal.h

@@ -0,0 +1,157 @@
+#pragma once
+#include "common/extended_types.h"
+
+#if !defined(NO_SANITIZE_UNDEFINED)
+#if defined(__clang__)
+    #define NO_SANITIZE_UNDEFINED __attribute__((__no_sanitize__("undefined")))
+#else
+    #define NO_SANITIZE_UNDEFINED
+#endif
+#endif
+
+namespace DB
+{
+template <class> struct Decimal;
+class DateTime64;
+
+using Decimal32 = Decimal<Int32>;
+using Decimal64 = Decimal<Int64>;
+using Decimal128 = Decimal<Int128>;
+using Decimal256 = Decimal<Int256>;
+
+template <class T>
+concept is_decimal =
+    std::is_same_v<T, Decimal32>
+    || std::is_same_v<T, Decimal64>
+    || std::is_same_v<T, Decimal128>
+    || std::is_same_v<T, Decimal256>
+    || std::is_same_v<T, DateTime64>;
+
+template <class T>
+concept is_over_big_int =
+    std::is_same_v<T, Int128>
+    || std::is_same_v<T, UInt128>
+    || std::is_same_v<T, Int256>
+    || std::is_same_v<T, UInt256>
+    || std::is_same_v<T, Decimal128>
+    || std::is_same_v<T, Decimal256>;
+
+template <class T> struct NativeTypeT { using Type = T; };
+template <is_decimal T> struct NativeTypeT<T> { using Type = typename T::NativeType; };
+template <class T> using NativeType = typename NativeTypeT<T>::Type;
+
+/// Own FieldType for Decimal.
+/// It is only a "storage" for decimal.
+/// To perform operations, you also have to provide a scale (number of digits after point).
+template <typename T>
+struct Decimal
+{
+    using NativeType = T;
+
+    constexpr Decimal() = default;
+    constexpr Decimal(Decimal<T> &&) = default;
+    constexpr Decimal(const Decimal<T> &) = default;
+
+    constexpr Decimal(const T & value_): value(value_) {}
+
+    template <typename U>
+    constexpr Decimal(const Decimal<U> & x): value(x.value) {}
+
+    constexpr Decimal<T> & operator = (Decimal<T> &&) = default;
+    constexpr Decimal<T> & operator = (const Decimal<T> &) = default;
+
+    constexpr operator T () const { return value; }
+
+    template <typename U>
+    constexpr U convertTo() const
+    {
+        if constexpr (is_decimal<U>)
+            return convertTo<typename U::NativeType>();
+        else
+            return static_cast<U>(value);
+    }
+
+    const Decimal<T> & operator += (const T & x) { value += x; return *this; }
+    const Decimal<T> & operator -= (const T & x) { value -= x; return *this; }
+    const Decimal<T> & operator *= (const T & x) { value *= x; return *this; }
+    const Decimal<T> & operator /= (const T & x) { value /= x; return *this; }
+    const Decimal<T> & operator %= (const T & x) { value %= x; return *this; }
+
+    template <typename U> const Decimal<T> & operator += (const Decimal<U> & x) { value += x.value; return *this; }
+    template <typename U> const Decimal<T> & operator -= (const Decimal<U> & x) { value -= x.value; return *this; }
+    template <typename U> const Decimal<T> & operator *= (const Decimal<U> & x) { value *= x.value; return *this; }
+    template <typename U> const Decimal<T> & operator /= (const Decimal<U> & x) { value /= x.value; return *this; }
+    template <typename U> const Decimal<T> & operator %= (const Decimal<U> & x) { value %= x.value; return *this; }
+
+    /// This is to avoid UB for sumWithOverflow()
+    void NO_SANITIZE_UNDEFINED addOverflow(const T & x) { value += x; }
+
+    T value;
+};
+
+template <typename T> inline bool operator< (const Decimal<T> & x, const Decimal<T> & y) { return x.value < y.value; }
+template <typename T> inline bool operator> (const Decimal<T> & x, const Decimal<T> & y) { return x.value > y.value; }
+template <typename T> inline bool operator<= (const Decimal<T> & x, const Decimal<T> & y) { return x.value <= y.value; }
+template <typename T> inline bool operator>= (const Decimal<T> & x, const Decimal<T> & y) { return x.value >= y.value; }
+template <typename T> inline bool operator== (const Decimal<T> & x, const Decimal<T> & y) { return x.value == y.value; }
+template <typename T> inline bool operator!= (const Decimal<T> & x, const Decimal<T> & y) { return x.value != y.value; }
+
+template <typename T> inline Decimal<T> operator+ (const Decimal<T> & x, const Decimal<T> & y) { return x.value + y.value; }
+template <typename T> inline Decimal<T> operator- (const Decimal<T> & x, const Decimal<T> & y) { return x.value - y.value; }
+template <typename T> inline Decimal<T> operator* (const Decimal<T> & x, const Decimal<T> & y) { return x.value * y.value; }
+template <typename T> inline Decimal<T> operator/ (const Decimal<T> & x, const Decimal<T> & y) { return x.value / y.value; }
+template <typename T> inline Decimal<T> operator- (const Decimal<T> & x) { return -x.value; }
+
+/// Distinguishable type to allow function resolution/deduction based on value type,
+/// but also relatively easy to convert to/from Decimal64.
+class DateTime64 : public Decimal64
+{
+public:
+    using Base = Decimal64;
+    using Base::Base;
+    using NativeType = Base::NativeType;
+
+    constexpr DateTime64(const Base & v): Base(v) {}
+};
+}
+
+constexpr DB::UInt64 max_uint_mask = std::numeric_limits<DB::UInt64>::max();
+
+namespace std
+{
+    template <typename T>
+    struct hash<DB::Decimal<T>>
+    {
+        size_t operator()(const DB::Decimal<T> & x) const { return hash<T>()(x.value); }
+    };
+
+    template <>
+    struct hash<DB::Decimal128>
+    {
+        size_t operator()(const DB::Decimal128 & x) const
+        {
+            return std::hash<DB::Int64>()(x.value >> 64)
+                ^ std::hash<DB::Int64>()(x.value & max_uint_mask);
+        }
+    };
+
+    template <>
+    struct hash<DB::DateTime64>
+    {
+        size_t operator()(const DB::DateTime64 & x) const
+        {
+            return std::hash<DB::DateTime64::NativeType>()(x);
+        }
+    };
+
+    template <>
+    struct hash<DB::Decimal256>
+    {
+        size_t operator()(const DB::Decimal256 & x) const
+        {
+            // FIXME temp solution
+            return std::hash<DB::Int64>()(static_cast<DB::Int64>(x.value >> 64 & max_uint_mask))
+                ^ std::hash<DB::Int64>()(static_cast<DB::Int64>(x.value & max_uint_mask));
+        }
+    };
+}

base/common/EnumReflection.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <magic_enum.hpp>
+#include <fmt/format.h>
+
+template <class T> concept is_enum = std::is_enum_v<T>;
+
+namespace detail
+{
+template <is_enum E, class F, size_t ...I>
+constexpr void static_for(F && f, std::index_sequence<I...>)
+{
+    (std::forward<F>(f)(std::integral_constant<E, magic_enum::enum_value<E>(I)>()) , ...);
+}
+}
+
+/**
+ * Iterate over enum values in compile-time (compile-time switch/case, loop unrolling).
+ *
+ * @example static_for<E>([](auto enum_value) { return template_func<enum_value>(); }
+ * ^ enum_value can be used as a template parameter
+ */
+template <is_enum E, class F>
+constexpr void static_for(F && f)
+{
+    constexpr size_t count = magic_enum::enum_count<E>();
+    detail::static_for<E>(std::forward<F>(f), std::make_index_sequence<count>());
+}
+
+/// Enable printing enum values as strings via fmt + magic_enum
+template <is_enum T>
+struct fmt::formatter<T> : fmt::formatter<std::string_view>
+{
+    constexpr auto format(T value, auto& format_context)
+    {
+        return formatter<string_view>::format(magic_enum::enum_name(value), format_context);
+    }
+};

base/common/extended_types.h

@@ -41,22 +41,14 @@ template <> struct is_unsigned<UInt256> { static constexpr bool value = true; };
 template <typename T>
 inline constexpr bool is_unsigned_v = is_unsigned<T>::value;
 
+template <class T> concept is_integer =
+    std::is_integral_v<T>
+    || std::is_same_v<T, Int128>
+    || std::is_same_v<T, UInt128>
+    || std::is_same_v<T, Int256>
+    || std::is_same_v<T, UInt256>;
 
-/// TODO: is_integral includes char, char8_t and wchar_t.
+template <class T> concept is_floating_point = std::is_floating_point_v<T>;
-template <typename T>
-struct is_integer
-{
-    static constexpr bool value = std::is_integral_v<T>;
-};
-
-template <> struct is_integer<Int128> { static constexpr bool value = true; };
-template <> struct is_integer<UInt128> { static constexpr bool value = true; };
-template <> struct is_integer<Int256> { static constexpr bool value = true; };
-template <> struct is_integer<UInt256> { static constexpr bool value = true; };
-
-template <typename T>
-inline constexpr bool is_integer_v = is_integer<T>::value;
-
 
 template <typename T>
 struct is_arithmetic

base/common/find_symbols.h

@@ -36,18 +36,7 @@
 
 namespace detail
 {
-
+template <char ...chars> constexpr bool is_in(char x) { return ((x == chars) || ...); }
-template <char s0>
-inline bool is_in(char x)
-{
-    return x == s0;
-}
-
-template <char s0, char s1, char... tail>
-inline bool is_in(char x)
-{
-    return x == s0 || is_in<s1, tail...>(x);
-}
 
 #if defined(__SSE2__)
 template <char s0>
@@ -67,16 +56,10 @@ inline __m128i mm_is_in(__m128i bytes)
 #endif
 
 template <bool positive>
-bool maybe_negate(bool x)
+constexpr bool maybe_negate(bool x) { return x == positive; }
-{
-    if constexpr (positive)
-        return x;
-    else
-        return !x;
-}
 
 template <bool positive>
-uint16_t maybe_negate(uint16_t x)
+constexpr uint16_t maybe_negate(uint16_t x)
 {
     if constexpr (positive)
         return x;
@@ -149,12 +132,13 @@ template <bool positive, ReturnMode return_mode, size_t num_chars,
     char c05 = 0, char c06 = 0, char c07 = 0, char c08 = 0,
     char c09 = 0, char c10 = 0, char c11 = 0, char c12 = 0,
     char c13 = 0, char c14 = 0, char c15 = 0, char c16 = 0>
-inline const char * find_first_symbols_sse42_impl(const char * const begin, const char * const end)
+inline const char * find_first_symbols_sse42(const char * const begin, const char * const end)
 {
     const char * pos = begin;
 
 #if defined(__SSE4_2__)
-#define MODE (_SIDD_UBYTE_OPS | _SIDD_CMP_EQUAL_ANY | _SIDD_LEAST_SIGNIFICANT)
+    constexpr int mode = _SIDD_UBYTE_OPS | _SIDD_CMP_EQUAL_ANY | _SIDD_LEAST_SIGNIFICANT;
+
     __m128i set = _mm_setr_epi8(c01, c02, c03, c04, c05, c06, c07, c08, c09, c10, c11, c12, c13, c14, c15, c16);
 
     for (; pos + 15 < end; pos += 16)
@@ -163,16 +147,15 @@ inline const char * find_first_symbols_sse42_impl(const char * const begin, cons
 
         if constexpr (positive)
         {
-            if (_mm_cmpestrc(set, num_chars, bytes, 16, MODE))
+            if (_mm_cmpestrc(set, num_chars, bytes, 16, mode))
-                return pos + _mm_cmpestri(set, num_chars, bytes, 16, MODE);
+                return pos + _mm_cmpestri(set, num_chars, bytes, 16, mode);
         }
         else
         {
-            if (_mm_cmpestrc(set, num_chars, bytes, 16, MODE | _SIDD_NEGATIVE_POLARITY))
+            if (_mm_cmpestrc(set, num_chars, bytes, 16, mode | _SIDD_NEGATIVE_POLARITY))
-                return pos + _mm_cmpestri(set, num_chars, bytes, 16, MODE | _SIDD_NEGATIVE_POLARITY);
+                return pos + _mm_cmpestri(set, num_chars, bytes, 16, mode | _SIDD_NEGATIVE_POLARITY);
         }
     }
-#undef MODE
 #endif
 
     for (; pos < end; ++pos)
@@ -197,20 +180,15 @@ inline const char * find_first_symbols_sse42_impl(const char * const begin, cons
 }
 
 
-template <bool positive, ReturnMode return_mode, char... symbols>
-inline const char * find_first_symbols_sse42(const char * begin, const char * end)
-{
-    return find_first_symbols_sse42_impl<positive, return_mode, sizeof...(symbols), symbols...>(begin, end);
-}
-
 /// NOTE No SSE 4.2 implementation for find_last_symbols_or_null. Not worth to do.
 
 template <bool positive, ReturnMode return_mode, char... symbols>
 inline const char * find_first_symbols_dispatch(const char * begin, const char * end)
+    requires(0 <= sizeof...(symbols) && sizeof...(symbols) <= 16)
 {
 #if defined(__SSE4_2__)
     if (sizeof...(symbols) >= 5)
-        return find_first_symbols_sse42<positive, return_mode, symbols...>(begin, end);
+        return find_first_symbols_sse42<positive, return_mode, sizeof...(symbols), symbols...>(begin, end);
     else
 #endif
         return find_first_symbols_sse2<positive, return_mode, symbols...>(begin, end);

base/common/strong_typedef.h

@@ -15,15 +15,15 @@ private:
 public:
     using UnderlyingType = T;
     template <class Enable = typename std::is_copy_constructible<T>::type>
-    explicit StrongTypedef(const T & t_) : t(t_) {}
+    constexpr explicit StrongTypedef(const T & t_) : t(t_) {}
     template <class Enable = typename std::is_move_constructible<T>::type>
-    explicit StrongTypedef(T && t_) : t(std::move(t_)) {}
+    constexpr explicit StrongTypedef(T && t_) : t(std::move(t_)) {}
 
     template <class Enable = typename std::is_default_constructible<T>::type>
-    StrongTypedef(): t() {}
+    constexpr StrongTypedef(): t() {}
 
-    StrongTypedef(const Self &) = default;
+    constexpr StrongTypedef(const Self &) = default;
-    StrongTypedef(Self &&) = default;
+    constexpr StrongTypedef(Self &&) = default;
 
     Self & operator=(const Self &) = default;
     Self & operator=(Self &&) = default;

contrib/CMakeLists.txt

@@ -33,6 +33,7 @@ endif()
 set_property(DIRECTORY PROPERTY EXCLUDE_FROM_ALL 1)
 
 add_subdirectory (abseil-cpp-cmake)
+add_subdirectory (magic-enum-cmake)
 add_subdirectory (boost-cmake)
 add_subdirectory (cctz-cmake)
 add_subdirectory (consistent-hashing)

contrib/magic-enum-cmake/CMakeLists.txt

@@ -0,0 +1,3 @@
+set (LIBRARY_DIR "${ClickHouse_SOURCE_DIR}/contrib/magic_enum")
+add_library (magic_enum INTERFACE)
+target_include_directories(magic_enum INTERFACE ${LIBRARY_DIR}/include)

contrib/magic_enum

@@ -0,0 +1 @@
+Subproject commit 38f86e4d093cfc9034a140d37de2168e3951bef3

docker/test/fasttest/run.sh

@@ -159,6 +159,7 @@ function clone_submodules
         cd "$FASTTEST_SOURCE"
 
         SUBMODULES_TO_UPDATE=(
+            contrib/magic_enum
             contrib/abseil-cpp
             contrib/boost
             contrib/zlib-ng

src/AggregateFunctions/AggregateFunctionAvg.h

@@ -21,11 +21,9 @@
 namespace DB
 {
 struct Settings;
-template <typename T>
-using DecimalOrVectorCol = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<T>, ColumnVector<T>>;
 
 template <typename T> constexpr bool DecimalOrExtendedInt =
-    IsDecimalNumber<T>
+    is_decimal<T>
     || std::is_same_v<T, Int128>
     || std::is_same_v<T, Int256>
     || std::is_same_v<T, UInt128>
@@ -44,7 +42,7 @@ struct AvgFraction
     /// Invoked only is either Numerator or Denominator are Decimal.
     Float64 NO_SANITIZE_UNDEFINED divideIfAnyDecimal(UInt32 num_scale, UInt32 denom_scale [[maybe_unused]]) const
     {
-        if constexpr (IsDecimalNumber<Numerator> && IsDecimalNumber<Denominator>)
+        if constexpr (is_decimal<Numerator> && is_decimal<Denominator>)
         {
             // According to the docs, num(S1) / denom(S2) would have scale S1
 
@@ -60,7 +58,7 @@ struct AvgFraction
         /// Numerator is always casted to Float64 to divide correctly if the denominator is not Float64.
         Float64 num_converted;
 
-        if constexpr (IsDecimalNumber<Numerator>)
+        if constexpr (is_decimal<Numerator>)
             num_converted = DecimalUtils::convertTo<Float64>(numerator, num_scale);
         else
             num_converted = static_cast<Float64>(numerator); /// all other types, including extended integral.
@@ -68,7 +66,7 @@ struct AvgFraction
         std::conditional_t<DecimalOrExtendedInt<Denominator>,
             Float64, Denominator> denom_converted;
 
-        if constexpr (IsDecimalNumber<Denominator>)
+        if constexpr (is_decimal<Denominator>)
             denom_converted = DecimalUtils::convertTo<Float64>(denominator, denom_scale);
         else if constexpr (DecimalOrExtendedInt<Denominator>)
             /// no way to divide Float64 and extended integral type without an explicit cast.
@@ -139,7 +137,7 @@ public:
 
     void insertResultInto(AggregateDataPtr __restrict place, IColumn & to, Arena *) const override
     {
-        if constexpr (IsDecimalNumber<Numerator> || IsDecimalNumber<Denominator>)
+        if constexpr (is_decimal<Numerator> || is_decimal<Denominator>)
             assert_cast<ColumnVector<Float64> &>(to).getData().push_back(
                 this->data(place).divideIfAnyDecimal(num_scale, denom_scale));
         else
@@ -222,7 +220,7 @@ private:
 };
 
 template <typename T>
-using AvgFieldType = std::conditional_t<IsDecimalNumber<T>,
+using AvgFieldType = std::conditional_t<is_decimal<T>,
     std::conditional_t<std::is_same_v<T, Decimal256>, Decimal256, Decimal128>,
     NearestFieldType<T>>;
 
@@ -239,7 +237,7 @@ public:
 
     void NO_SANITIZE_UNDEFINED add(AggregateDataPtr __restrict place, const IColumn ** columns, size_t row_num, Arena *) const final
     {
-        this->data(place).numerator += static_cast<const DecimalOrVectorCol<T> &>(*columns[0]).getData()[row_num];
+        this->data(place).numerator += static_cast<const ColumnVectorOrDecimal<T> &>(*columns[0]).getData()[row_num];
         ++this->data(place).denominator;
     }
 

src/AggregateFunctions/AggregateFunctionAvgWeighted.h

@@ -8,7 +8,7 @@ namespace DB
 struct Settings;
 
 template <typename T>
-using AvgWeightedFieldType = std::conditional_t<IsDecimalNumber<T>,
+using AvgWeightedFieldType = std::conditional_t<is_decimal<T>,
     std::conditional_t<std::is_same_v<T, Decimal256>, Decimal256, Decimal128>,
     std::conditional_t<DecimalOrExtendedInt<T>,
         Float64, // no way to do UInt128 * UInt128, better cast to Float64
@@ -34,10 +34,10 @@ public:
 
     void NO_SANITIZE_UNDEFINED add(AggregateDataPtr __restrict place, const IColumn ** columns, size_t row_num, Arena *) const override
     {
-        const auto& weights = static_cast<const DecimalOrVectorCol<Weight> &>(*columns[1]);
+        const auto& weights = static_cast<const ColumnVectorOrDecimal<Weight> &>(*columns[1]);
 
         this->data(place).numerator += static_cast<Numerator>(
-            static_cast<const DecimalOrVectorCol<Value> &>(*columns[0]).getData()[row_num]) *
+            static_cast<const ColumnVectorOrDecimal<Value> &>(*columns[0]).getData()[row_num]) *
             static_cast<Numerator>(weights.getData()[row_num]);
 
         this->data(place).denominator += static_cast<Denominator>(weights.getData()[row_num]);

src/AggregateFunctions/AggregateFunctionGroupArrayMoving.cpp

@@ -25,14 +25,14 @@ namespace
 template <typename T, typename LimitNumberOfElements>
 struct MovingSum
 {
-    using Data = MovingSumData<std::conditional_t<IsDecimalNumber<T>, Decimal128, NearestFieldType<T>>>;
+    using Data = MovingSumData<std::conditional_t<is_decimal<T>, Decimal128, NearestFieldType<T>>>;
     using Function = MovingImpl<T, LimitNumberOfElements, Data>;
 };
 
 template <typename T, typename LimitNumberOfElements>
 struct MovingAvg
 {
-    using Data = MovingAvgData<std::conditional_t<IsDecimalNumber<T>, Decimal128, Float64>>;
+    using Data = MovingAvgData<std::conditional_t<is_decimal<T>, Decimal128, Float64>>;
     using Function = MovingImpl<T, LimitNumberOfElements, Data>;
 };
 

src/AggregateFunctions/AggregateFunctionGroupArrayMoving.h

@@ -87,18 +87,10 @@ class MovingImpl final
 public:
     using ResultT = typename Data::Accumulator;
 
-    using ColumnSource = std::conditional_t<IsDecimalNumber<T>,
+    using ColumnSource = ColumnVectorOrDecimal<T>;
-        ColumnDecimal<T>,
-        ColumnVector<T>>;
 
     /// Probably for overflow function in the future.
-    using ColumnResult = std::conditional_t<IsDecimalNumber<ResultT>,
+    using ColumnResult = ColumnVectorOrDecimal<ResultT>;
-        ColumnDecimal<ResultT>,
-        ColumnVector<ResultT>>;
-
-    using DataTypeResult = std::conditional_t<IsDecimalNumber<ResultT>,
-        DataTypeDecimal<ResultT>,
-        DataTypeNumber<ResultT>>;
 
     explicit MovingImpl(const DataTypePtr & data_type_, UInt64 window_size_ = std::numeric_limits<UInt64>::max())
         : IAggregateFunctionDataHelper<Data, MovingImpl<T, Tlimit_num_elems, Data>>({data_type_}, {})
@@ -106,14 +98,7 @@ public:
 
     String getName() const override { return Data::name; }
 
-    DataTypePtr getReturnType() const override
+    DataTypePtr getReturnType() const override { return std::make_shared<DataTypeArray>(getReturnTypeElement()); }
-    {
-        if constexpr (IsDecimalNumber<ResultT>)
-            return std::make_shared<DataTypeArray>(std::make_shared<DataTypeResult>(
-                DataTypeResult::maxPrecision(), getDecimalScale(*this->argument_types.at(0))));
-        else
-            return std::make_shared<DataTypeArray>(std::make_shared<DataTypeResult>());
-    }
 
     void NO_SANITIZE_UNDEFINED add(AggregateDataPtr __restrict place, const IColumn ** columns, size_t row_num, Arena * arena) const override
     {
@@ -196,6 +181,18 @@ public:
     {
         return true;
     }
+
+private:
+    auto getReturnTypeElement() const
+    {
+        if constexpr (!is_decimal<ResultT>)
+            return std::make_shared<DataTypeNumber<ResultT>>();
+        else
+        {
+            using Res = DataTypeDecimal<ResultT>;
+            return std::make_shared<Res>(Res::maxPrecision(), getDecimalScale(*this->argument_types.at(0)));
+        }
+    }
 };
 
 #undef AGGREGATE_FUNCTION_MOVING_MAX_ARRAY_SIZE

src/AggregateFunctions/AggregateFunctionMinMaxAny.h

@@ -44,7 +44,7 @@ struct SingleValueDataFixed
 {
 private:
     using Self = SingleValueDataFixed;
-    using ColVecType = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<T>, ColumnVector<T>>;
+    using ColVecType = ColumnVectorOrDecimal<T>;
 
     bool has_value = false; /// We need to remember if at least one value has been passed. This is necessary for AggregateFunctionIf.
     T value;

src/AggregateFunctions/AggregateFunctionQuantile.h

@@ -67,10 +67,10 @@ class AggregateFunctionQuantile final : public IAggregateFunctionDataHelper<Data
     AggregateFunctionQuantile<Value, Data, Name, has_second_arg, FloatReturnType, returns_many>>
 {
 private:
-    using ColVecType = std::conditional_t<IsDecimalNumber<Value>, ColumnDecimal<Value>, ColumnVector<Value>>;
+    using ColVecType = ColumnVectorOrDecimal<Value>;
 
     static constexpr bool returns_float = !(std::is_same_v<FloatReturnType, void>);
-    static_assert(!IsDecimalNumber<Value> || !returns_float);
+    static_assert(!is_decimal<Value> || !returns_float);
 
     QuantileLevels<Float64> levels;
 

src/AggregateFunctions/AggregateFunctionStatisticsSimple.h

@@ -49,7 +49,7 @@ struct StatFuncOneArg
     using Type1 = T;
     using Type2 = T;
     using ResultType = std::conditional_t<std::is_same_v<T, Float32>, Float32, Float64>;
-    using Data = std::conditional_t<IsDecimalNumber<T>, VarMomentsDecimal<Decimal128, _level>, VarMoments<ResultType, _level>>;
+    using Data = std::conditional_t<is_decimal<T>, VarMomentsDecimal<Decimal128, _level>, VarMoments<ResultType, _level>>;
 
     static constexpr StatisticsFunctionKind kind = _kind;
     static constexpr UInt32 num_args = 1;
@@ -75,8 +75,8 @@ class AggregateFunctionVarianceSimple final
 public:
     using T1 = typename StatFunc::Type1;
     using T2 = typename StatFunc::Type2;
-    using ColVecT1 = std::conditional_t<IsDecimalNumber<T1>, ColumnDecimal<T1>, ColumnVector<T1>>;
+    using ColVecT1 = ColumnVectorOrDecimal<T1>;
-    using ColVecT2 = std::conditional_t<IsDecimalNumber<T2>, ColumnDecimal<T2>, ColumnVector<T2>>;
+    using ColVecT2 = ColumnVectorOrDecimal<T2>;
     using ResultType = typename StatFunc::ResultType;
     using ColVecResult = ColumnVector<ResultType>;
 
@@ -132,7 +132,7 @@ public:
                 static_cast<ResultType>(static_cast<const ColVecT2 &>(*columns[1]).getData()[row_num]));
         else
         {
-            if constexpr (IsDecimalNumber<T1>)
+            if constexpr (is_decimal<T1>)
             {
                 this->data(place).add(static_cast<ResultType>(
                     static_cast<const ColVecT1 &>(*columns[0]).getData()[row_num].value));
@@ -163,7 +163,7 @@ public:
         const auto & data = this->data(place);
         auto & dst = static_cast<ColVecResult &>(to).getData();
 
-        if constexpr (IsDecimalNumber<T1>)
+        if constexpr (is_decimal<T1>)
         {
             if constexpr (StatFunc::kind == StatisticsFunctionKind::varPop)
                 dst.push_back(data.getPopulation(src_scale * 2));

src/AggregateFunctions/AggregateFunctionSum.cpp

@@ -20,10 +20,9 @@ template <typename T>
 struct SumSimple
 {
     /// @note It uses slow Decimal128 (cause we need such a variant). sumWithOverflow is faster for Decimal32/64
-    using ResultType = std::conditional_t<IsDecimalNumber<T>,
+    using ResultType = std::conditional_t<is_decimal<T>,
                                         std::conditional_t<std::is_same_v<T, Decimal256>, Decimal256, Decimal128>,
                                         NearestFieldType<T>>;
-    // using ResultType = std::conditional_t<IsDecimalNumber<T>, Decimal128, NearestFieldType<T>>;
     using AggregateDataType = AggregateFunctionSumData<ResultType>;
     using Function = AggregateFunctionSum<T, ResultType, AggregateDataType, AggregateFunctionTypeSum>;
 };
@@ -47,7 +46,7 @@ struct SumKahan
 template <typename T> using AggregateFunctionSumSimple = typename SumSimple<T>::Function;
 template <typename T> using AggregateFunctionSumWithOverflow = typename SumSameType<T>::Function;
 template <typename T> using AggregateFunctionSumKahan =
-    std::conditional_t<IsDecimalNumber<T>, typename SumSimple<T>::Function, typename SumKahan<T>::Function>;
+    std::conditional_t<is_decimal<T>, typename SumSimple<T>::Function, typename SumKahan<T>::Function>;
 
 
 template <template <typename> class Function>

src/AggregateFunctions/AggregateFunctionSum.h

@@ -104,8 +104,8 @@ struct AggregateFunctionSumData
         const auto * end = ptr + count;
 
         if constexpr (
-            (is_integer_v<T> && !is_big_int_v<T>)
+            (is_integer<T> && !is_big_int_v<T>)
-            || (IsDecimalNumber<T> && !std::is_same_v<T, Decimal256> && !std::is_same_v<T, Decimal128>))
+            || (is_decimal<T> && !std::is_same_v<T, Decimal256> && !std::is_same_v<T, Decimal128>))
         {
             /// For integers we can vectorize the operation if we replace the null check using a multiplication (by 0 for null, 1 for not null)
             /// https://quick-bench.com/q/MLTnfTvwC2qZFVeWHfOBR3U7a8I
@@ -334,9 +334,7 @@ class AggregateFunctionSum final : public IAggregateFunctionDataHelper<Data, Agg
 public:
     static constexpr bool DateTime64Supported = false;
 
-    using ResultDataType = std::conditional_t<IsDecimalNumber<T>, DataTypeDecimal<TResult>, DataTypeNumber<TResult>>;
+    using ColVecType = ColumnVectorOrDecimal<T>;
-    using ColVecType = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<T>, ColumnVector<T>>;
-    using ColVecResult = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<TResult>, ColumnVector<TResult>>;
 
     String getName() const override
     {
@@ -361,10 +359,13 @@ public:
 
     DataTypePtr getReturnType() const override
     {
-        if constexpr (IsDecimalNumber<T>)
+        if constexpr (!is_decimal<T>)
-            return std::make_shared<ResultDataType>(ResultDataType::maxPrecision(), scale);
+            return std::make_shared<DataTypeNumber<TResult>>();
         else
-            return std::make_shared<ResultDataType>();
+        {
+            using DataType = DataTypeDecimal<TResult>;
+            return std::make_shared<DataType>(DataType::maxPrecision(), scale);
+        }
     }
 
     bool allocatesMemoryInArena() const override { return false; }
@@ -431,8 +432,7 @@ public:
 
     void insertResultInto(AggregateDataPtr __restrict place, IColumn & to, Arena *) const override
     {
-        auto & column = assert_cast<ColVecResult &>(to);
+        castColumnToResult(to).getData().push_back(this->data(place).get());
-        column.getData().push_back(this->data(place).get());
     }
 
 #if USE_EMBEDDED_COMPILER
@@ -511,6 +511,14 @@ public:
 
 private:
     UInt32 scale;
+
+    static constexpr auto & castColumnToResult(IColumn & to)
+    {
+        if constexpr (is_decimal<T>)
+            return assert_cast<ColumnDecimal<TResult> &>(to);
+        else
+            return assert_cast<ColumnVector<TResult> &>(to);
+    }
 };
 
 }

src/AggregateFunctions/AggregateFunctionSumCount.h

@@ -8,8 +8,6 @@
 namespace DB
 {
 template <typename T>
-using DecimalOrNumberDataType = std::conditional_t<IsDecimalNumber<T>, DataTypeDecimal<AvgFieldType<T>>, DataTypeNumber<AvgFieldType<T>>>;
-template <typename T>
 class AggregateFunctionSumCount final : public AggregateFunctionAvgBase<AvgFieldType<T>, UInt64, AggregateFunctionSumCount<T>>
 {
 public:
@@ -20,20 +18,13 @@ public:
 
     DataTypePtr getReturnType() const override
     {
-        DataTypes types;
+        auto second_elem = std::make_shared<DataTypeUInt64>();
-        if constexpr (IsDecimalNumber<T>)
+        return std::make_shared<DataTypeTuple>(DataTypes{getReturnTypeFirstElement(), std::move(second_elem)});
-            types.emplace_back(std::make_shared<DecimalOrNumberDataType<T>>(DecimalOrNumberDataType<T>::maxPrecision(), scale));
-        else
-            types.emplace_back(std::make_shared<DecimalOrNumberDataType<T>>());
-
-        types.emplace_back(std::make_shared<DataTypeUInt64>());
-
-        return std::make_shared<DataTypeTuple>(types);
     }
 
     void insertResultInto(AggregateDataPtr __restrict place, IColumn & to, Arena *) const final
     {
-        assert_cast<DecimalOrVectorCol<AvgFieldType<T>> &>((assert_cast<ColumnTuple &>(to)).getColumn(0)).getData().push_back(
+        assert_cast<ColumnVectorOrDecimal<AvgFieldType<T>> &>((assert_cast<ColumnTuple &>(to)).getColumn(0)).getData().push_back(
             this->data(place).numerator);
 
         assert_cast<ColumnUInt64 &>((assert_cast<ColumnTuple &>(to)).getColumn(1)).getData().push_back(
@@ -42,7 +33,7 @@ public:
 
     void NO_SANITIZE_UNDEFINED add(AggregateDataPtr __restrict place, const IColumn ** columns, size_t row_num, Arena *) const final
     {
-        this->data(place).numerator += static_cast<const DecimalOrVectorCol<T> &>(*columns[0]).getData()[row_num];
+        this->data(place).numerator += static_cast<const ColumnVectorOrDecimal<T> &>(*columns[0]).getData()[row_num];
         ++this->data(place).denominator;
     }
 
@@ -59,6 +50,19 @@ public:
 
 private:
     UInt32 scale;
+
+    auto getReturnTypeFirstElement() const
+    {
+        using FieldType = AvgFieldType<T>;
+
+        if constexpr (!is_decimal<T>)
+            return std::make_shared<DataTypeNumber<FieldType>>();
+        else
+        {
+            using DataType = DataTypeDecimal<FieldType>;
+            return std::make_shared<DataType>(DataType::maxPrecision(), scale);
+        }
+    }
 };
 
 }

src/AggregateFunctions/AggregateFunctionSumMap.h

@@ -190,7 +190,7 @@ public:
                     continue;
 
                 decltype(merged_maps.begin()) it;
-                if constexpr (IsDecimalNumber<T>)
+                if constexpr (is_decimal<T>)
                 {
                     // FIXME why is storing NearestFieldType not enough, and we
                     // have to check for decimals again here?
@@ -217,7 +217,7 @@ public:
                     new_values.resize(size);
                     new_values[col] = value;
 
-                    if constexpr (IsDecimalNumber<T>)
+                    if constexpr (is_decimal<T>)
                     {
                         UInt32 scale = static_cast<const ColumnDecimal<T> &>(key_column).getData().getScale();
                         merged_maps.emplace(DecimalField<T>(key, scale), std::move(new_values));
@@ -280,7 +280,7 @@ public:
             for (size_t col = 0; col < values_types.size(); ++col)
                 values_serializations[col]->deserializeBinary(values[col], buf);
 
-            if constexpr (IsDecimalNumber<T>)
+            if constexpr (is_decimal<T>)
                 merged_maps[key.get<DecimalField<T>>()] = values;
             else
                 merged_maps[key.get<T>()] = values;
@@ -396,7 +396,7 @@ private:
     using Base = AggregateFunctionMapBase<T, Self, FieldVisitorSum, overflow, tuple_argument, true>;
 
     /// ARCADIA_BUILD disallow unordered_set for big ints for some reason
-    static constexpr const bool allow_hash = !OverBigInt<T>;
+    static constexpr const bool allow_hash = !is_over_big_int<T>;
     using ContainerT = std::conditional_t<allow_hash, std::unordered_set<T>, std::set<T>>;
 
     ContainerT keys_to_keep;

src/AggregateFunctions/QuantileExactWeighted.h

@@ -30,7 +30,7 @@ struct QuantileExactWeighted
     };
 
     using Weight = UInt64;
-    using UnderlyingType = typename NativeType<Value>::Type;
+    using UnderlyingType = NativeType<Value>;
     using Hasher = std::conditional_t<std::is_same_v<Value, Decimal128>, Int128Hash, HashCRC32<UnderlyingType>>;
 
     /// When creating, the hash table must be small.

src/AggregateFunctions/ReservoirSampler.h

@@ -121,7 +121,7 @@ public:
     {
         if (samples.empty())
         {
-            if (DB::IsDecimalNumber<T>)
+            if (DB::is_decimal<T>)
                 return 0;
             return onEmpty<double>();
         }
@@ -134,7 +134,7 @@ public:
         size_t right_index = left_index + 1;
         if (right_index == samples.size())
         {
-            if constexpr (DB::IsDecimalNumber<T>)
+            if constexpr (DB::is_decimal<T>)
                 return static_cast<double>(samples[left_index].value);
             else
                 return static_cast<double>(samples[left_index]);
@@ -143,7 +143,7 @@ public:
         double left_coef = right_index - index;
         double right_coef = index - left_index;
 
-        if constexpr (DB::IsDecimalNumber<T>)
+        if constexpr (DB::is_decimal<T>)
             return static_cast<double>(samples[left_index].value) * left_coef + static_cast<double>(samples[right_index].value) * right_coef;
         else
             return static_cast<double>(samples[left_index]) * left_coef + static_cast<double>(samples[right_index]) * right_coef;

src/Columns/ColumnAggregateFunction.cpp

@@ -506,8 +506,9 @@ static void pushBackAndCreateState(ColumnAggregateFunction::Container & data, Ar
 void ColumnAggregateFunction::insert(const Field & x)
 {
     if (x.getType() != Field::Types::AggregateFunctionState)
-        throw Exception(String("Inserting field of type ") + x.getTypeName() + " into ColumnAggregateFunction. "
+        throw Exception(ErrorCodes::LOGICAL_ERROR,
-                        "Expected " + Field::Types::toString(Field::Types::AggregateFunctionState), ErrorCodes::LOGICAL_ERROR);
+            "Inserting field of type {} into ColumnAggregateFunction. Expected {}",
+            x.getTypeName(), Field::Types::AggregateFunctionState);
 
     const auto & field_name = x.get<const AggregateFunctionStateData &>().name;
     if (type_string != field_name)

src/Columns/ColumnDecimal.cpp

@@ -38,7 +38,7 @@ template class DecimalPaddedPODArray<Decimal128>;
 template class DecimalPaddedPODArray<Decimal256>;
 template class DecimalPaddedPODArray<DateTime64>;
 
-template <typename T>
+template <is_decimal T>
 int ColumnDecimal<T>::compareAt(size_t n, size_t m, const IColumn & rhs_, int) const
 {
     auto & other = static_cast<const Self &>(rhs_);
@@ -50,7 +50,7 @@ int ColumnDecimal<T>::compareAt(size_t n, size_t m, const IColumn & rhs_, int) c
     return decimalLess<T>(b, a, other.scale, scale) ? 1 : (decimalLess<T>(a, b, scale, other.scale) ? -1 : 0);
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::compareColumn(const IColumn & rhs, size_t rhs_row_num,
                                      PaddedPODArray<UInt64> * row_indexes, PaddedPODArray<Int8> & compare_results,
                                      int direction, int nan_direction_hint) const
@@ -59,13 +59,13 @@ void ColumnDecimal<T>::compareColumn(const IColumn & rhs, size_t rhs_row_num,
                                                          compare_results, direction, nan_direction_hint);
 }
 
-template <typename T>
+template <is_decimal T>
 bool ColumnDecimal<T>::hasEqualValues() const
 {
     return this->template hasEqualValuesImpl<ColumnDecimal<T>>();
 }
 
-template <typename T>
+template <is_decimal T>
 StringRef ColumnDecimal<T>::serializeValueIntoArena(size_t n, Arena & arena, char const *& begin) const
 {
     auto * pos = arena.allocContinue(sizeof(T), begin);
@@ -73,20 +73,20 @@ StringRef ColumnDecimal<T>::serializeValueIntoArena(size_t n, Arena & arena, cha
     return StringRef(pos, sizeof(T));
 }
 
-template <typename T>
+template <is_decimal T>
 const char * ColumnDecimal<T>::deserializeAndInsertFromArena(const char * pos)
 {
     data.push_back(unalignedLoad<T>(pos));
     return pos + sizeof(T);
 }
 
-template <typename T>
+template <is_decimal T>
 const char * ColumnDecimal<T>::skipSerializedInArena(const char * pos) const
 {
     return pos + sizeof(T);
 }
 
-template <typename T>
+template <is_decimal T>
 UInt64 ColumnDecimal<T>::get64([[maybe_unused]] size_t n) const
 {
     if constexpr (sizeof(T) > sizeof(UInt64))
@@ -95,13 +95,13 @@ UInt64 ColumnDecimal<T>::get64([[maybe_unused]] size_t n) const
         return static_cast<NativeT>(data[n]);
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::updateHashWithValue(size_t n, SipHash & hash) const
 {
     hash.update(data[n].value);
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::updateWeakHash32(WeakHash32 & hash) const
 {
     auto s = data.size();
@@ -122,13 +122,13 @@ void ColumnDecimal<T>::updateWeakHash32(WeakHash32 & hash) const
     }
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::updateHashFast(SipHash & hash) const
 {
     hash.update(reinterpret_cast<const char *>(data.data()), size() * sizeof(data[0]));
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::getPermutation(bool reverse, size_t limit, int , IColumn::Permutation & res) const
 {
 #if 1 /// TODO: perf test
@@ -147,7 +147,7 @@ void ColumnDecimal<T>::getPermutation(bool reverse, size_t limit, int , IColumn:
     permutation(reverse, limit, res);
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::updatePermutation(bool reverse, size_t limit, int, IColumn::Permutation & res, EqualRanges & equal_ranges) const
 {
     if (equal_ranges.empty())
@@ -228,7 +228,7 @@ void ColumnDecimal<T>::updatePermutation(bool reverse, size_t limit, int, IColum
     }
 }
 
-template <typename T>
+template <is_decimal T>
 ColumnPtr ColumnDecimal<T>::permute(const IColumn::Permutation & perm, size_t limit) const
 {
     size_t size = limit ? std::min(data.size(), limit) : data.size();
@@ -244,7 +244,7 @@ ColumnPtr ColumnDecimal<T>::permute(const IColumn::Permutation & perm, size_t li
     return res;
 }
 
-template <typename T>
+template <is_decimal T>
 MutableColumnPtr ColumnDecimal<T>::cloneResized(size_t size) const
 {
     auto res = this->create(0, scale);
@@ -268,7 +268,7 @@ MutableColumnPtr ColumnDecimal<T>::cloneResized(size_t size) const
     return res;
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::insertData(const char * src, size_t /*length*/)
 {
     T tmp;
@@ -276,7 +276,7 @@ void ColumnDecimal<T>::insertData(const char * src, size_t /*length*/)
     data.emplace_back(tmp);
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::insertRangeFrom(const IColumn & src, size_t start, size_t length)
 {
     const ColumnDecimal & src_vec = assert_cast<const ColumnDecimal &>(src);
@@ -292,7 +292,7 @@ void ColumnDecimal<T>::insertRangeFrom(const IColumn & src, size_t start, size_t
     memcpy(data.data() + old_size, &src_vec.data[start], length * sizeof(data[0]));
 }
 
-template <typename T>
+template <is_decimal T>
 ColumnPtr ColumnDecimal<T>::filter(const IColumn::Filter & filt, ssize_t result_size_hint) const
 {
     size_t size = data.size();
@@ -321,19 +321,19 @@ ColumnPtr ColumnDecimal<T>::filter(const IColumn::Filter & filt, ssize_t result_
     return res;
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::expand(const IColumn::Filter & mask, bool inverted)
 {
     expandDataByMask<T>(data, mask, inverted);
 }
 
-template <typename T>
+template <is_decimal T>
 ColumnPtr ColumnDecimal<T>::index(const IColumn & indexes, size_t limit) const
 {
     return selectIndexImpl(*this, indexes, limit);
 }
 
-template <typename T>
+template <is_decimal T>
 ColumnPtr ColumnDecimal<T>::replicate(const IColumn::Offsets & offsets) const
 {
     size_t size = data.size();
@@ -360,13 +360,13 @@ ColumnPtr ColumnDecimal<T>::replicate(const IColumn::Offsets & offsets) const
     return res;
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::gather(ColumnGathererStream & gatherer)
 {
     gatherer.gather(*this);
 }
 
-template <typename T>
+template <is_decimal T>
 ColumnPtr ColumnDecimal<T>::compress() const
 {
     size_t source_size = data.size() * sizeof(T);
@@ -390,7 +390,7 @@ ColumnPtr ColumnDecimal<T>::compress() const
         });
 }
 
-template <typename T>
+template <is_decimal T>
 void ColumnDecimal<T>::getExtremes(Field & min, Field & max) const
 {
     if (data.empty())

src/Columns/ColumnDecimal.h

@@ -7,6 +7,8 @@
 #include <Core/DecimalFunctions.h>
 #include <Common/typeid_cast.h>
 #include <common/sort.h>
+#include <Core/TypeId.h>
+#include <Core/TypeName.h>
 
 #include <cmath>
 
@@ -59,11 +61,9 @@ extern template class DecimalPaddedPODArray<Decimal256>;
 extern template class DecimalPaddedPODArray<DateTime64>;
 
 /// A ColumnVector for Decimals
-template <typename T>
+template <is_decimal T>
 class ColumnDecimal final : public COWHelper<ColumnVectorHelper, ColumnDecimal<T>>
 {
-    static_assert(IsDecimalNumber<T>);
-
 private:
     using Self = ColumnDecimal;
     friend class COWHelper<ColumnVectorHelper, Self>;
@@ -210,7 +210,12 @@ protected:
     }
 };
 
-template <typename T>
+template <class> class ColumnVector;
+template <class T> struct ColumnVectorOrDecimalT { using Col = ColumnVector<T>; };
+template <is_decimal T> struct ColumnVectorOrDecimalT<T> { using Col = ColumnDecimal<T>; };
+template <class T> using ColumnVectorOrDecimal = typename ColumnVectorOrDecimalT<T>::Col;
+
+template <is_decimal T>
 template <typename Type>
 ColumnPtr ColumnDecimal<T>::indexImpl(const PaddedPODArray<Type> & indexes, size_t limit) const
 {

src/Columns/ColumnVector.h

@@ -7,6 +7,8 @@
 #include <common/unaligned.h>
 #include <Core/Field.h>
 #include <Common/assert_cast.h>
+#include <Core/TypeId.h>
+#include <Core/TypeName.h>
 
 
 namespace DB
@@ -102,7 +104,7 @@ template <class U> struct CompareHelper<Float64, U> : public FloatCompareHelper<
 template <typename T>
 class ColumnVector final : public COWHelper<ColumnVectorHelper, ColumnVector<T>>
 {
-    static_assert(!IsDecimalNumber<T>);
+    static_assert(!is_decimal<T>);
 
 private:
     using Self = ColumnVector;

src/Common/ErrorCodes.cpp

@@ -494,7 +494,6 @@
     M(523, UNKNOWN_ROW_POLICY) \
     M(524, ALTER_OF_COLUMN_IS_FORBIDDEN) \
     M(525, INCORRECT_DISK_INDEX) \
-    M(526, UNKNOWN_VOLUME_TYPE) \
     M(527, NO_SUITABLE_FUNCTION_IMPLEMENTATION) \
     M(528, CASSANDRA_INTERNAL_ERROR) \
     M(529, NOT_A_LEADER) \

src/Common/ExternalLoaderStatus.cpp

@@ -1,39 +0,0 @@
-#include <Common/ExternalLoaderStatus.h>
-
-namespace DB
-{
-    String toString(ExternalLoaderStatus status)
-    {
-        using Status = ExternalLoaderStatus;
-        switch (status)
-        {
-            case Status::NOT_LOADED: return "NOT_LOADED";
-            case Status::LOADED: return "LOADED";
-            case Status::FAILED: return "FAILED";
-            case Status::LOADING: return "LOADING";
-            case Status::FAILED_AND_RELOADING: return "FAILED_AND_RELOADING";
-            case Status::LOADED_AND_RELOADING: return "LOADED_AND_RELOADING";
-            case Status::NOT_EXIST: return "NOT_EXIST";
-        }
-    __builtin_unreachable();
-    }
-
-    std::vector<std::pair<String, Int8>> getStatusEnumAllPossibleValues()
-    {
-        using Status = ExternalLoaderStatus;
-        return std::vector<std::pair<String, Int8>>{
-            {toString(Status::NOT_LOADED), static_cast<Int8>(Status::NOT_LOADED)},
-            {toString(Status::LOADED), static_cast<Int8>(Status::LOADED)},
-            {toString(Status::FAILED), static_cast<Int8>(Status::FAILED)},
-            {toString(Status::LOADING), static_cast<Int8>(Status::LOADING)},
-            {toString(Status::LOADED_AND_RELOADING), static_cast<Int8>(Status::LOADED_AND_RELOADING)},
-            {toString(Status::FAILED_AND_RELOADING), static_cast<Int8>(Status::FAILED_AND_RELOADING)},
-            {toString(Status::NOT_EXIST), static_cast<Int8>(Status::NOT_EXIST)},
-        };
-    }
-
-    std::ostream & operator<<(std::ostream & out, ExternalLoaderStatus status)
-    {
-        return out << toString(status);
-    }
-}

src/Common/ExternalLoaderStatus.h

@@ -1,13 +1,12 @@
 #pragma once
 
 #include <vector>
-#include <utility>
+#include <common/EnumReflection.h>
-#include <ostream>
 #include <common/types.h>
 
 namespace DB
 {
-    enum class ExternalLoaderStatus
+    enum class ExternalLoaderStatus : Int8
     {
         NOT_LOADED, /// Object hasn't been tried to load. This is an initial state.
         LOADED, /// Object has been loaded successfully.
@@ -18,7 +17,14 @@ namespace DB
         NOT_EXIST, /// Object with this name wasn't found in the configuration.
     };
 
-    String toString(ExternalLoaderStatus status);
+    inline std::vector<std::pair<String, Int8>> getStatusEnumAllPossibleValues()
-    std::vector<std::pair<String, Int8>> getStatusEnumAllPossibleValues();
+    {
-    std::ostream & operator<<(std::ostream & out, ExternalLoaderStatus status);
+        std::vector<std::pair<String, Int8>> out;
+        out.reserve(magic_enum::enum_count<ExternalLoaderStatus>());
+
+        for (const auto & [value, str] : magic_enum::enum_entries<ExternalLoaderStatus>())
+            out.emplace_back(std::string{str}, static_cast<Int8>(value));
+
+        return out;
+    }
 }

src/Common/FieldVisitorConvertToNumber.h

@@ -116,7 +116,7 @@ public:
     template <typename U, typename = std::enable_if_t<is_big_int_v<U>> >
     T operator() (const U & x) const
     {
-        if constexpr (IsDecimalNumber<T>)
+        if constexpr (is_decimal<T>)
             return static_cast<T>(static_cast<typename T::NativeType>(x));
         else if constexpr (std::is_same_v<T, UInt128>)
             throw Exception("No conversion to old UInt128 from " + demangle(typeid(U).name()), ErrorCodes::NOT_IMPLEMENTED);

src/Common/HashTable/Hash.h

@@ -197,12 +197,8 @@ inline size_t DefaultHash64(std::enable_if_t<(sizeof(T) > sizeof(UInt64)), T> ke
     __builtin_unreachable();
 }
 
-
-template <typename T, typename Enable = void>
-struct DefaultHash;
-
 template <typename T>
-struct DefaultHash<T, std::enable_if_t<!DB::IsDecimalNumber<T>>>
+struct DefaultHash
 {
     size_t operator() (T key) const
     {
@@ -210,8 +206,8 @@ struct DefaultHash<T, std::enable_if_t<!DB::IsDecimalNumber<T>>>
     }
 };
 
-template <typename T>
+template <DB::is_decimal T>
-struct DefaultHash<T, std::enable_if_t<DB::IsDecimalNumber<T>>>
+struct DefaultHash<T>
 {
     size_t operator() (T key) const
     {

src/Common/IntervalKind.cpp

@@ -9,23 +9,6 @@ namespace ErrorCodes
     extern const int SYNTAX_ERROR;
 }
 
-const char * IntervalKind::toString() const
-{
-    switch (kind)
-    {
-        case IntervalKind::Second: return "Second";
-        case IntervalKind::Minute: return "Minute";
-        case IntervalKind::Hour: return "Hour";
-        case IntervalKind::Day: return "Day";
-        case IntervalKind::Week: return "Week";
-        case IntervalKind::Month: return "Month";
-        case IntervalKind::Quarter: return "Quarter";
-        case IntervalKind::Year: return "Year";
-    }
-    __builtin_unreachable();
-}
-
-
 Int32 IntervalKind::toAvgSeconds() const
 {
     switch (kind)

src/Common/IntervalKind.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <common/types.h>
-
+#include <common/EnumReflection.h>
 
 namespace DB
 {
@@ -24,7 +24,7 @@ struct IntervalKind
     IntervalKind(Kind kind_ = Second) : kind(kind_) {}
     operator Kind() const { return kind; }
 
-    const char * toString() const;
+    constexpr std::string_view toString() const { return magic_enum::enum_name(kind); }
 
     /// Returns number of seconds in one interval.
     /// For `Month`, `Quarter` and `Year` the function returns an average number of seconds.

src/Common/JSONBuilder.h

@@ -33,7 +33,7 @@ using ItemPtr = std::unique_ptr<IItem>;
 class JSONString : public IItem
 {
 public:
-    explicit JSONString(std::string value_) : value(std::move(value_)) {}
+    JSONString(std::string_view value_) : value(value_) {}
     void format(const FormatSettings & settings, FormatContext & context) override;
 
 private:
@@ -97,6 +97,7 @@ public:
     void add(std::string key, ItemPtr value) { values.emplace_back(Pair{.key = std::move(key), .value = std::move(value)}); }
     void add(std::string key, std::string value) { add(std::move(key), std::make_unique<JSONString>(std::move(value))); }
     void add(std::string key, const char * value) { add(std::move(key), std::make_unique<JSONString>(value)); }
+    void add(std::string key, std::string_view value) { add(std::move(key), std::make_unique<JSONString>(value)); }
     void add(std::string key, bool value) { add(std::move(key), std::make_unique<JSONBool>(std::move(value))); }
 
     template <typename T, std::enable_if_t<std::is_arithmetic<T>::value, bool> = true>

src/Common/RadixSort.h

@@ -187,7 +187,7 @@ struct RadixSortIntTraits
 
 template <typename T>
 using RadixSortNumTraits = std::conditional_t<
-    is_integer_v<T>,
+    is_integer<T>,
     std::conditional_t<is_unsigned_v<T>, RadixSortUIntTraits<T>, RadixSortIntTraits<T>>,
     RadixSortFloatTraits<T>>;
 

src/Common/parseAddress.cpp

@@ -43,7 +43,7 @@ std::pair<std::string, UInt16> parseAddress(const std::string & str, UInt16 defa
 
         UInt16 port_number;
         ReadBufferFromMemory port_buf(port, end - port);
-        if (!tryReadText<UInt16>(port_number, port_buf) || !port_buf.eof())
+        if (!tryReadText(port_number, port_buf) || !port_buf.eof())
         {
             throw Exception(ErrorCodes::BAD_ARGUMENTS,
                 "Illegal port passed to function parseAddress: {}", port);

src/Common/tests/gtest_wide_integer.cpp

@@ -13,22 +13,22 @@
 
 static_assert(is_signed_v<Int128>);
 static_assert(!is_unsigned_v<Int128>);
-static_assert(is_integer_v<Int128>);
+static_assert(is_integer<Int128>);
 static_assert(sizeof(Int128) == 16);
 
 static_assert(is_signed_v<Int256>);
 static_assert(!is_unsigned_v<Int256>);
-static_assert(is_integer_v<Int256>);
+static_assert(is_integer<Int256>);
 static_assert(sizeof(Int256) == 32);
 
 static_assert(!is_signed_v<UInt128>);
 static_assert(is_unsigned_v<UInt128>);
-static_assert(is_integer_v<UInt128>);
+static_assert(is_integer<UInt128>);
 static_assert(sizeof(UInt128) == 16);
 
 static_assert(!is_signed_v<UInt256>);
 static_assert(is_unsigned_v<UInt256>);
-static_assert(is_integer_v<UInt256>);
+static_assert(is_integer<UInt256>);
 static_assert(sizeof(UInt256) == 32);
 
 

src/Compression/tests/gtest_compressionCodec.cpp

@@ -685,7 +685,7 @@ auto SequentialGenerator = [](auto stride = 1)
 template <typename T>
 using uniform_distribution =
 typename std::conditional_t<std::is_floating_point_v<T>, std::uniform_real_distribution<T>,
-        typename std::conditional_t<is_integer_v<T>, std::uniform_int_distribution<T>, void>>;
+        typename std::conditional_t<is_integer<T>, std::uniform_int_distribution<T>, void>>;
 
 
 template <typename T = Int32>

src/Core/AccurateComparison.h

@@ -33,7 +33,7 @@ bool lessOp(A a, B b)
         return false;
 
     /// int vs int
-    if constexpr (is_integer_v<A> && is_integer_v<B>)
+    if constexpr (is_integer<A> && is_integer<B>)
     {
         /// same signedness
         if constexpr (is_signed_v<A> == is_signed_v<B>)
@@ -49,7 +49,7 @@ bool lessOp(A a, B b)
     }
 
     /// int vs float
-    if constexpr (is_integer_v<A> && std::is_floating_point_v<B>)
+    if constexpr (is_integer<A> && std::is_floating_point_v<B>)
     {
         if constexpr (sizeof(A) <= 4)
             return static_cast<double>(a) < static_cast<double>(b);
@@ -57,7 +57,7 @@ bool lessOp(A a, B b)
         return DecomposedFloat<B>(b).greater(a);
     }
 
-    if constexpr (std::is_floating_point_v<A> && is_integer_v<B>)
+    if constexpr (std::is_floating_point_v<A> && is_integer<B>)
     {
         if constexpr (sizeof(B) <= 4)
             return static_cast<double>(a) < static_cast<double>(b);
@@ -65,8 +65,8 @@ bool lessOp(A a, B b)
         return DecomposedFloat<A>(a).less(b);
     }
 
-    static_assert(is_integer_v<A> || std::is_floating_point_v<A>);
+    static_assert(is_integer<A> || std::is_floating_point_v<A>);
-    static_assert(is_integer_v<B> || std::is_floating_point_v<B>);
+    static_assert(is_integer<B> || std::is_floating_point_v<B>);
     __builtin_unreachable();
 }
 
@@ -109,7 +109,7 @@ bool equalsOp(A a, B b)
         return false;
 
     /// int vs int
-    if constexpr (is_integer_v<A> && is_integer_v<B>)
+    if constexpr (is_integer<A> && is_integer<B>)
     {
         /// same signedness
         if constexpr (is_signed_v<A> == is_signed_v<B>)
@@ -125,7 +125,7 @@ bool equalsOp(A a, B b)
     }
 
     /// int vs float
-    if constexpr (is_integer_v<A> && std::is_floating_point_v<B>)
+    if constexpr (is_integer<A> && std::is_floating_point_v<B>)
     {
         if constexpr (sizeof(A) <= 4)
             return static_cast<double>(a) == static_cast<double>(b);
@@ -133,7 +133,7 @@ bool equalsOp(A a, B b)
         return DecomposedFloat<B>(b).equals(a);
     }
 
-    if constexpr (std::is_floating_point_v<A> && is_integer_v<B>)
+    if constexpr (std::is_floating_point_v<A> && is_integer<B>)
     {
         if constexpr (sizeof(B) <= 4)
             return static_cast<double>(a) == static_cast<double>(b);

src/Core/DecimalComparison.h

@@ -47,21 +47,21 @@ template <> struct ConstructDecInt<32> { using Type = Int256; };
 template <typename T, typename U>
 struct DecCompareInt
 {
-    using Type = typename ConstructDecInt<(!IsDecimalNumber<U> || sizeof(T) > sizeof(U)) ? sizeof(T) : sizeof(U)>::Type;
+    using Type = typename ConstructDecInt<(!is_decimal<U> || sizeof(T) > sizeof(U)) ? sizeof(T) : sizeof(U)>::Type;
     using TypeA = Type;
     using TypeB = Type;
 };
 
 ///
 template <typename A, typename B, template <typename, typename> typename Operation, bool _check_overflow = true,
-    bool _actual = IsDecimalNumber<A> || IsDecimalNumber<B>>
+    bool _actual = is_decimal<A> || is_decimal<B>>
 class DecimalComparison
 {
 public:
     using CompareInt = typename DecCompareInt<A, B>::Type;
     using Op = Operation<CompareInt, CompareInt>;
-    using ColVecA = std::conditional_t<IsDecimalNumber<A>, ColumnDecimal<A>, ColumnVector<A>>;
+    using ColVecA = ColumnVectorOrDecimal<A>;
-    using ColVecB = std::conditional_t<IsDecimalNumber<B>, ColumnDecimal<B>, ColumnVector<B>>;
+    using ColVecB = ColumnVectorOrDecimal<B>;
 
     using ArrayA = typename ColVecA::Container;
     using ArrayB = typename ColVecB::Container;
@@ -116,7 +116,7 @@ private:
     }
 
     template <typename T, typename U>
-    static std::enable_if_t<IsDecimalNumber<T> && IsDecimalNumber<U>, Shift>
+    static std::enable_if_t<is_decimal<T> && is_decimal<U>, Shift>
     getScales(const DataTypePtr & left_type, const DataTypePtr & right_type)
     {
         const DataTypeDecimalBase<T> * decimal0 = checkDecimalBase<T>(*left_type);
@@ -138,7 +138,7 @@ private:
     }
 
     template <typename T, typename U>
-    static std::enable_if_t<IsDecimalNumber<T> && !IsDecimalNumber<U>, Shift>
+    static std::enable_if_t<is_decimal<T> && !is_decimal<U>, Shift>
     getScales(const DataTypePtr & left_type, const DataTypePtr &)
     {
         Shift shift;
@@ -149,7 +149,7 @@ private:
     }
 
     template <typename T, typename U>
-    static std::enable_if_t<!IsDecimalNumber<T> && IsDecimalNumber<U>, Shift>
+    static std::enable_if_t<!is_decimal<T> && is_decimal<U>, Shift>
     getScales(const DataTypePtr &, const DataTypePtr & right_type)
     {
         Shift shift;
@@ -222,13 +222,13 @@ private:
     static NO_INLINE UInt8 apply(A a, B b, CompareInt scale [[maybe_unused]])
     {
         CompareInt x;
-        if constexpr (IsDecimalNumber<A>)
+        if constexpr (is_decimal<A>)
             x = a.value;
         else
             x = a;
 
         CompareInt y;
-        if constexpr (IsDecimalNumber<B>)
+        if constexpr (is_decimal<B>)
             y = b.value;
         else
             y = b;

src/Core/DecimalFunctions.h

@@ -223,16 +223,16 @@ inline typename DecimalType::NativeType getFractionalPart(const DecimalType & de
 template <typename To, typename DecimalType, typename ReturnType>
 ReturnType convertToImpl(const DecimalType & decimal, size_t scale, To & result)
 {
-    using NativeT = typename DecimalType::NativeType;
+    using DecimalNativeType = typename DecimalType::NativeType;
-    static constexpr bool throw_exception = std::is_same_v<ReturnType, void>;
+    static constexpr bool throw_exception = std::is_void_v<ReturnType>;
 
     if constexpr (std::is_floating_point_v<To>)
     {
-        result = static_cast<To>(decimal.value) / static_cast<To>(scaleMultiplier<NativeT>(scale));
+        result = static_cast<To>(decimal.value) / static_cast<To>(scaleMultiplier<DecimalNativeType>(scale));
     }
-    else if constexpr (is_integer_v<To> && (sizeof(To) >= sizeof(NativeT)))
+    else if constexpr (is_integer<To> && (sizeof(To) >= sizeof(DecimalNativeType)))
     {
-        NativeT whole = getWholePart(decimal, scale);
+        DecimalNativeType whole = getWholePart(decimal, scale);
 
         if constexpr (is_unsigned_v<To>)
         {
@@ -247,15 +247,14 @@ ReturnType convertToImpl(const DecimalType & decimal, size_t scale, To & result)
 
         result = static_cast<To>(whole);
     }
-    else if constexpr (is_integer_v<To>)
+    else if constexpr (is_integer<To>)
     {
-        using ToNativeT = typename NativeType<To>::Type;
+        using CastTo = std::conditional_t<(is_big_int_v<DecimalNativeType> && std::is_same_v<To, UInt8>), uint8_t, To>;
-        using CastTo = std::conditional_t<(is_big_int_v<NativeT> && std::is_same_v<ToNativeT, UInt8>), uint8_t, ToNativeT>;
 
-        const NativeT whole = getWholePart(decimal, scale);
+        const DecimalNativeType whole = getWholePart(decimal, scale);
 
-        static const constexpr CastTo min_to = std::numeric_limits<ToNativeT>::min();
+        static const constexpr CastTo min_to = std::numeric_limits<To>::min();
-        static const constexpr CastTo max_to = std::numeric_limits<ToNativeT>::max();
+        static const constexpr CastTo max_to = std::numeric_limits<To>::max();
 
         if (whole < min_to || whole > max_to)
         {

src/Core/Field.cpp

@@ -487,11 +487,11 @@ template bool decimalLessOrEqual<DateTime64>(DateTime64 x, DateTime64 y, UInt32
 inline void writeText(const Null & x, WriteBuffer & buf)
 {
     if (x.isNegativeInfinity())
-        writeText(std::string("-Inf"), buf);
+        writeText("-Inf", buf);
     if (x.isPositiveInfinity())
-        writeText(std::string("+Inf"), buf);
+        writeText("+Inf", buf);
     else
-        writeText(std::string("NULL"), buf);
+        writeText("NULL", buf);
 }
 
 String toString(const Field & x)

src/Core/Field.h

@@ -14,7 +14,7 @@
 #include <Core/UUID.h>
 #include <common/DayNum.h>
 #include <common/strong_typedef.h>
-
+#include <common/EnumReflection.h>
 
 namespace DB
 {
@@ -283,33 +283,6 @@ public:
             Map = 26,
             UUID = 27,
         };
-
-        static const char * toString(Which which)
-        {
-            switch (which)
-            {
-                case Null:    return "Null";
-                case UInt64:  return "UInt64";
-                case UInt128: return "UInt128";
-                case UInt256: return "UInt256";
-                case Int64:   return "Int64";
-                case Int128:  return "Int128";
-                case Int256:  return "Int256";
-                case UUID:    return "UUID";
-                case Float64: return "Float64";
-                case String:  return "String";
-                case Array:   return "Array";
-                case Tuple:   return "Tuple";
-                case Map:     return "Map";
-                case Decimal32:  return "Decimal32";
-                case Decimal64:  return "Decimal64";
-                case Decimal128: return "Decimal128";
-                case Decimal256: return "Decimal256";
-                case AggregateFunctionState: return "AggregateFunctionState";
-            }
-
-            throw Exception("Bad type of Field", ErrorCodes::BAD_TYPE_OF_FIELD);
-        }
     };
 
 
@@ -417,7 +390,8 @@ public:
 
 
     Types::Which getType() const { return which; }
-    const char * getTypeName() const { return Types::toString(which); }
+
+    constexpr std::string_view getTypeName() const { return magic_enum::enum_name(which); }
 
     bool isNull() const { return which == Types::Null; }
     template <typename T>
@@ -808,7 +782,8 @@ NearestFieldType<std::decay_t<T>> & Field::get()
     constexpr Field::Types::Which target = TypeToEnum<StoredType>::value;
     if (target != which
            && (!isInt64OrUInt64FieldType(target) || !isInt64OrUInt64FieldType(which)))
-        throw Exception(ErrorCodes::LOGICAL_ERROR, "Invalid Field get from type {} to type {}", Types::toString(which), Types::toString(target));
+        throw Exception(ErrorCodes::LOGICAL_ERROR,
+            "Invalid Field get from type {} to type {}", which, target);
 #endif
 
     StoredType * MAY_ALIAS ptr = reinterpret_cast<StoredType *>(&storage);
@@ -821,8 +796,11 @@ template <typename T>
 auto & Field::safeGet()
 {
     const Types::Which requested = TypeToEnum<NearestFieldType<std::decay_t<T>>>::value;
+
     if (which != requested)
-        throw Exception("Bad get: has " + std::string(getTypeName()) + ", requested " + std::string(Types::toString(requested)), ErrorCodes::BAD_GET);
+        throw Exception(ErrorCodes::BAD_GET,
+            "Bad get: has {}, requested {}", getTypeName(), requested);
+
     return get<T>();
 }
 
@@ -859,12 +837,6 @@ T safeGet(Field & field)
     return field.template safeGet<T>();
 }
 
-template <> inline constexpr const char * TypeName<Array> = "Array";
-template <> inline constexpr const char * TypeName<Tuple> = "Tuple";
-template <> inline constexpr const char * TypeName<Map> = "Map";
-template <> inline constexpr const char * TypeName<AggregateFunctionStateData> = "AggregateFunctionState";
-
-
 template <typename T>
 Field::Field(T && rhs, enable_if_not_field_or_bool_or_stringlike_t<T>) //-V730
 {

src/Core/TypeId.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <Core/Types.h>
+
+namespace DB
+{
+/**
+ * Obtain TypeIndex value from real type if possible.
+ *
+ * Returns TypeIndex::Nothing if type was not present in TypeIndex;
+ * Returns TypeIndex element otherwise.
+ *
+ * @example TypeId<UInt8> == TypeIndex::UInt8
+ * @example TypeId<MySuperType> == TypeIndex::Nothing
+ */
+template <class T> inline constexpr TypeIndex TypeId = TypeIndex::Nothing;
+
+template <TypeIndex index> struct ReverseTypeIdT : std::false_type {};
+
+/**
+ * Obtain real type from TypeIndex if possible.
+ *
+ * Returns a type alias if is corresponds to TypeIndex value.
+ * Yields a compiler error otherwise.
+ *
+ * @example ReverseTypeId<TypeIndex::UInt8> == UInt8
+ */
+template <TypeIndex index> using ReverseTypeId = typename ReverseTypeIdT<index>::T;
+template <TypeIndex index> constexpr bool HasReverseTypeId = ReverseTypeIdT<index>::value;
+
+#define TYPEID_MAP(_A) \
+    template <> inline constexpr TypeIndex TypeId<_A> = TypeIndex::_A; \
+    template <> struct ReverseTypeIdT<TypeIndex::_A> : std::true_type { using T = _A; };
+
+TYPEID_MAP(UInt8)
+TYPEID_MAP(UInt16)
+TYPEID_MAP(UInt32)
+TYPEID_MAP(UInt64)
+TYPEID_MAP(UInt128)
+TYPEID_MAP(UInt256)
+TYPEID_MAP(Int8)
+TYPEID_MAP(Int16)
+TYPEID_MAP(Int32)
+TYPEID_MAP(Int64)
+TYPEID_MAP(Int128)
+TYPEID_MAP(Int256)
+TYPEID_MAP(Float32)
+TYPEID_MAP(Float64)
+TYPEID_MAP(UUID)
+
+TYPEID_MAP(Decimal32)
+TYPEID_MAP(Decimal64)
+TYPEID_MAP(Decimal128)
+TYPEID_MAP(Decimal256)
+TYPEID_MAP(DateTime64)
+
+TYPEID_MAP(String)
+
+struct Array;
+TYPEID_MAP(Array)
+}

src/Core/TypeName.h

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <Core/Types.h>
+
+namespace DB
+{
+struct Array;
+struct Tuple;
+struct Map;
+struct AggregateFunctionStateData;
+
+template <class T> constexpr const char * TypeName = "";
+
+template <> inline constexpr const char * TypeName<UInt8> = "UInt8";
+template <> inline constexpr const char * TypeName<UInt16> = "UInt16";
+template <> inline constexpr const char * TypeName<UInt32> = "UInt32";
+template <> inline constexpr const char * TypeName<UInt64> = "UInt64";
+template <> inline constexpr const char * TypeName<UInt128> = "UInt128";
+template <> inline constexpr const char * TypeName<UInt256> = "UInt256";
+template <> inline constexpr const char * TypeName<Int8> = "Int8";
+template <> inline constexpr const char * TypeName<Int16> = "Int16";
+template <> inline constexpr const char * TypeName<Int32> = "Int32";
+template <> inline constexpr const char * TypeName<Int64> = "Int64";
+template <> inline constexpr const char * TypeName<Int128> = "Int128";
+template <> inline constexpr const char * TypeName<Int256> = "Int256";
+template <> inline constexpr const char * TypeName<Float32> = "Float32";
+template <> inline constexpr const char * TypeName<Float64> = "Float64";
+template <> inline constexpr const char * TypeName<String> = "String";
+template <> inline constexpr const char * TypeName<UUID> = "UUID";
+template <> inline constexpr const char * TypeName<Decimal32> = "Decimal32";
+template <> inline constexpr const char * TypeName<Decimal64> = "Decimal64";
+template <> inline constexpr const char * TypeName<Decimal128> = "Decimal128";
+template <> inline constexpr const char * TypeName<Decimal256> = "Decimal256";
+template <> inline constexpr const char * TypeName<DateTime64> = "DateTime64";
+template <> inline constexpr const char * TypeName<Array> = "Array";
+template <> inline constexpr const char * TypeName<Tuple> = "Tuple";
+template <> inline constexpr const char * TypeName<Map> = "Map";
+template <> inline constexpr const char * TypeName<AggregateFunctionStateData> = "AggregateFunctionState";
+}

src/Core/Types.h

@@ -4,7 +4,7 @@
 #include <string>
 #include <vector>
 #include <common/strong_typedef.h>
-#include <common/extended_types.h>
+#include <common/Decimal.h>
 #include <common/defines.h>
 
 
@@ -99,254 +99,6 @@ using Int256 = ::Int256;
 
 STRONG_TYPEDEF(UInt128, UUID)
 
-
-template <typename T> constexpr const char * TypeName = "";
-
-template <> inline constexpr const char * TypeName<UInt8> = "UInt8";
-template <> inline constexpr const char * TypeName<UInt16> = "UInt16";
-template <> inline constexpr const char * TypeName<UInt32> = "UInt32";
-template <> inline constexpr const char * TypeName<UInt64> = "UInt64";
-template <> inline constexpr const char * TypeName<UInt128> = "UInt128";
-template <> inline constexpr const char * TypeName<UInt256> = "UInt256";
-template <> inline constexpr const char * TypeName<Int8> = "Int8";
-template <> inline constexpr const char * TypeName<Int16> = "Int16";
-template <> inline constexpr const char * TypeName<Int32> = "Int32";
-template <> inline constexpr const char * TypeName<Int64> = "Int64";
-template <> inline constexpr const char * TypeName<Int128> = "Int128";
-template <> inline constexpr const char * TypeName<Int256> = "Int256";
-template <> inline constexpr const char * TypeName<Float32> = "Float32";
-template <> inline constexpr const char * TypeName<Float64> = "Float64";
-template <> inline constexpr const char * TypeName<String> = "String";
-template <> inline constexpr const char * TypeName<UUID> = "UUID";
-
-/// TODO Try to remove it.
-template <typename T> constexpr TypeIndex TypeId = TypeIndex::Nothing;
-template <> inline constexpr TypeIndex TypeId<UInt8> = TypeIndex::UInt8;
-template <> inline constexpr TypeIndex TypeId<UInt16> = TypeIndex::UInt16;
-template <> inline constexpr TypeIndex TypeId<UInt32> = TypeIndex::UInt32;
-template <> inline constexpr TypeIndex TypeId<UInt64> = TypeIndex::UInt64;
-template <> inline constexpr TypeIndex TypeId<UInt128> = TypeIndex::UInt128;
-template <> inline constexpr TypeIndex TypeId<UInt256> = TypeIndex::UInt256;
-template <> inline constexpr TypeIndex TypeId<Int8> = TypeIndex::Int8;
-template <> inline constexpr TypeIndex TypeId<Int16> = TypeIndex::Int16;
-template <> inline constexpr TypeIndex TypeId<Int32> = TypeIndex::Int32;
-template <> inline constexpr TypeIndex TypeId<Int64> = TypeIndex::Int64;
-template <> inline constexpr TypeIndex TypeId<Int128> = TypeIndex::Int128;
-template <> inline constexpr TypeIndex TypeId<Int256> = TypeIndex::Int256;
-template <> inline constexpr TypeIndex TypeId<Float32> = TypeIndex::Float32;
-template <> inline constexpr TypeIndex TypeId<Float64> = TypeIndex::Float64;
-template <> inline constexpr TypeIndex TypeId<UUID> = TypeIndex::UUID;
-
-
 /// Not a data type in database, defined just for convenience.
 using Strings = std::vector<String>;
-
-/// Own FieldType for Decimal.
-/// It is only a "storage" for decimal. To perform operations, you also have to provide a scale (number of digits after point).
-template <typename T>
-struct Decimal
-{
-    using NativeType = T;
-
-    Decimal() = default;
-    Decimal(Decimal<T> &&) = default;
-    Decimal(const Decimal<T> &) = default;
-
-    Decimal(const T & value_)
-    :   value(value_)
-    {}
-
-    template <typename U>
-    Decimal(const Decimal<U> & x)
-    :   value(x.value)
-    {}
-
-    constexpr Decimal<T> & operator = (Decimal<T> &&) = default;
-    constexpr Decimal<T> & operator = (const Decimal<T> &) = default;
-
-    operator T () const { return value; }
-
-    template <typename U>
-    U convertTo() const
-    {
-        /// no IsDecimalNumber defined yet
-        if constexpr (std::is_same_v<U, Decimal<Int32>> ||
-                      std::is_same_v<U, Decimal<Int64>> ||
-                      std::is_same_v<U, Decimal<Int128>> ||
-                      std::is_same_v<U, Decimal<Int256>>)
-        {
-            return convertTo<typename U::NativeType>();
-        }
-        else
-            return static_cast<U>(value);
-    }
-
-    const Decimal<T> & operator += (const T & x) { value += x; return *this; }
-    const Decimal<T> & operator -= (const T & x) { value -= x; return *this; }
-    const Decimal<T> & operator *= (const T & x) { value *= x; return *this; }
-    const Decimal<T> & operator /= (const T & x) { value /= x; return *this; }
-    const Decimal<T> & operator %= (const T & x) { value %= x; return *this; }
-
-    template <typename U> const Decimal<T> & operator += (const Decimal<U> & x) { value += x.value; return *this; }
-    template <typename U> const Decimal<T> & operator -= (const Decimal<U> & x) { value -= x.value; return *this; }
-    template <typename U> const Decimal<T> & operator *= (const Decimal<U> & x) { value *= x.value; return *this; }
-    template <typename U> const Decimal<T> & operator /= (const Decimal<U> & x) { value /= x.value; return *this; }
-    template <typename U> const Decimal<T> & operator %= (const Decimal<U> & x) { value %= x.value; return *this; }
-
-    /// This is to avoid UB for sumWithOverflow()
-    void NO_SANITIZE_UNDEFINED addOverflow(const T & x) { value += x; }
-
-    T value;
-};
-
-template <typename T> inline bool operator< (const Decimal<T> & x, const Decimal<T> & y) { return x.value < y.value; }
-template <typename T> inline bool operator> (const Decimal<T> & x, const Decimal<T> & y) { return x.value > y.value; }
-template <typename T> inline bool operator<= (const Decimal<T> & x, const Decimal<T> & y) { return x.value <= y.value; }
-template <typename T> inline bool operator>= (const Decimal<T> & x, const Decimal<T> & y) { return x.value >= y.value; }
-template <typename T> inline bool operator== (const Decimal<T> & x, const Decimal<T> & y) { return x.value == y.value; }
-template <typename T> inline bool operator!= (const Decimal<T> & x, const Decimal<T> & y) { return x.value != y.value; }
-
-template <typename T> inline Decimal<T> operator+ (const Decimal<T> & x, const Decimal<T> & y) { return x.value + y.value; }
-template <typename T> inline Decimal<T> operator- (const Decimal<T> & x, const Decimal<T> & y) { return x.value - y.value; }
-template <typename T> inline Decimal<T> operator* (const Decimal<T> & x, const Decimal<T> & y) { return x.value * y.value; }
-template <typename T> inline Decimal<T> operator/ (const Decimal<T> & x, const Decimal<T> & y) { return x.value / y.value; }
-template <typename T> inline Decimal<T> operator- (const Decimal<T> & x) { return -x.value; }
-
-using Decimal32 = Decimal<Int32>;
-using Decimal64 = Decimal<Int64>;
-using Decimal128 = Decimal<Int128>;
-using Decimal256 = Decimal<Int256>;
-
-// Distinguishable type to allow function resolution/deduction based on value type,
-// but also relatively easy to convert to/from Decimal64.
-class DateTime64 : public Decimal64
-{
-public:
-    using Base = Decimal64;
-    using Base::Base;
-
-    DateTime64(const Base & v)
-        : Base(v)
-    {}
-};
-
-template <> inline constexpr const char * TypeName<Decimal32> = "Decimal32";
-template <> inline constexpr const char * TypeName<Decimal64> = "Decimal64";
-template <> inline constexpr const char * TypeName<Decimal128> = "Decimal128";
-template <> inline constexpr const char * TypeName<Decimal256> = "Decimal256";
-template <> inline constexpr const char * TypeName<DateTime64> = "DateTime64";
-
-template <> inline constexpr TypeIndex TypeId<Decimal32> = TypeIndex::Decimal32;
-template <> inline constexpr TypeIndex TypeId<Decimal64> = TypeIndex::Decimal64;
-template <> inline constexpr TypeIndex TypeId<Decimal128> = TypeIndex::Decimal128;
-template <> inline constexpr TypeIndex TypeId<Decimal256> = TypeIndex::Decimal256;
-template <> inline constexpr TypeIndex TypeId<DateTime64> = TypeIndex::DateTime64;
-
-template <typename T> constexpr bool IsDecimalNumber = false;
-template <> inline constexpr bool IsDecimalNumber<Decimal32> = true;
-template <> inline constexpr bool IsDecimalNumber<Decimal64> = true;
-template <> inline constexpr bool IsDecimalNumber<Decimal128> = true;
-template <> inline constexpr bool IsDecimalNumber<Decimal256> = true;
-template <> inline constexpr bool IsDecimalNumber<DateTime64> = true;
-
-template <typename T> struct NativeType { using Type = T; };
-template <> struct NativeType<Decimal32> { using Type = Int32; };
-template <> struct NativeType<Decimal64> { using Type = Int64; };
-template <> struct NativeType<Decimal128> { using Type = Int128; };
-template <> struct NativeType<Decimal256> { using Type = Int256; };
-template <> struct NativeType<DateTime64> { using Type = Int64; };
-
-template <typename T> constexpr bool OverBigInt = false;
-template <> inline constexpr bool OverBigInt<Int128> = true;
-template <> inline constexpr bool OverBigInt<UInt128> = true;
-template <> inline constexpr bool OverBigInt<Int256> = true;
-template <> inline constexpr bool OverBigInt<UInt256> = true;
-template <> inline constexpr bool OverBigInt<Decimal128> = true;
-template <> inline constexpr bool OverBigInt<Decimal256> = true;
-
-inline constexpr const char * getTypeName(TypeIndex idx)
-{
-    switch (idx)
-    {
-        case TypeIndex::Nothing:    return "Nothing";
-        case TypeIndex::UInt8:      return "UInt8";
-        case TypeIndex::UInt16:     return "UInt16";
-        case TypeIndex::UInt32:     return "UInt32";
-        case TypeIndex::UInt64:     return "UInt64";
-        case TypeIndex::UInt128:    return "UInt128";
-        case TypeIndex::UInt256:    return "UInt256";
-        case TypeIndex::Int8:       return "Int8";
-        case TypeIndex::Int16:      return "Int16";
-        case TypeIndex::Int32:      return "Int32";
-        case TypeIndex::Int64:      return "Int64";
-        case TypeIndex::Int128:     return "Int128";
-        case TypeIndex::Int256:     return "Int256";
-        case TypeIndex::Float32:    return "Float32";
-        case TypeIndex::Float64:    return "Float64";
-        case TypeIndex::Date:       return "Date";
-        case TypeIndex::Date32:     return "Date32";
-        case TypeIndex::DateTime:   return "DateTime";
-        case TypeIndex::DateTime64: return "DateTime64";
-        case TypeIndex::String:     return "String";
-        case TypeIndex::FixedString: return "FixedString";
-        case TypeIndex::Enum8:      return "Enum8";
-        case TypeIndex::Enum16:     return "Enum16";
-        case TypeIndex::Decimal32:  return "Decimal32";
-        case TypeIndex::Decimal64:  return "Decimal64";
-        case TypeIndex::Decimal128: return "Decimal128";
-        case TypeIndex::Decimal256: return "Decimal256";
-        case TypeIndex::UUID:       return "UUID";
-        case TypeIndex::Array:      return "Array";
-        case TypeIndex::Tuple:      return "Tuple";
-        case TypeIndex::Set:        return "Set";
-        case TypeIndex::Interval:   return "Interval";
-        case TypeIndex::Nullable:   return "Nullable";
-        case TypeIndex::Function:   return "Function";
-        case TypeIndex::AggregateFunction: return "AggregateFunction";
-        case TypeIndex::LowCardinality: return "LowCardinality";
-        case TypeIndex::Map:        return "Map";
-    }
-
-    __builtin_unreachable();
-}
-
-}
-
-/// Specialization of `std::hash` for the Decimal<T> types.
-namespace std
-{
-    template <typename T>
-    struct hash<DB::Decimal<T>> { size_t operator()(const DB::Decimal<T> & x) const { return hash<T>()(x.value); } };
-
-    template <>
-    struct hash<DB::Decimal128>
-    {
-        size_t operator()(const DB::Decimal128 & x) const
-        {
-            return std::hash<DB::Int64>()(x.value >> 64)
-                ^ std::hash<DB::Int64>()(x.value & std::numeric_limits<DB::UInt64>::max());
-        }
-    };
-
-    template <>
-    struct hash<DB::DateTime64>
-    {
-        size_t operator()(const DB::DateTime64 & x) const
-        {
-            return std::hash<std::decay_t<decltype(x)>::NativeType>()(x);
-        }
-    };
-
-
-    template <>
-    struct hash<DB::Decimal256>
-    {
-        size_t operator()(const DB::Decimal256 & x) const
-        {
-            // temp solution
-            static constexpr DB::UInt64 max_uint_mask = std::numeric_limits<DB::UInt64>::max();
-            return std::hash<DB::Int64>()(static_cast<DB::Int64>(x.value >> 64 & max_uint_mask))
-                ^ std::hash<DB::Int64>()(static_cast<DB::Int64>(x.value & max_uint_mask));
-        }
-    };
 }

src/Core/callOnTypeIndex.h

@@ -164,7 +164,7 @@ class DataTypeDateTime;
 class DataTypeDateTime64;
 template <typename T> class DataTypeEnum;
 template <typename T> class DataTypeNumber;
-template <typename T> class DataTypeDecimal;
+template <is_decimal T> class DataTypeDecimal;
 
 
 template <typename T, typename F, typename... ExtraArgs>

src/DataTypes/DataTypeDecimalBase.cpp

@@ -28,19 +28,19 @@ bool decimalCheckArithmeticOverflow(ContextPtr context)
     return context->getSettingsRef().decimal_check_overflow;
 }
 
-template <typename T>
+template <is_decimal T>
 Field DataTypeDecimalBase<T>::getDefault() const
 {
     return DecimalField(T(0), scale);
 }
 
-template <typename T>
+template <is_decimal T>
 MutableColumnPtr DataTypeDecimalBase<T>::createColumn() const
 {
     return ColumnType::create(0, scale);
 }
 
-template <typename T>
+template <is_decimal T>
 T DataTypeDecimalBase<T>::getScaleMultiplier(UInt32 scale_)
 {
     return DecimalUtils::scaleMultiplier<typename T::NativeType>(scale_);

src/DataTypes/DataTypeDecimalBase.h

@@ -53,11 +53,9 @@ inline UInt32 leastDecimalPrecisionFor(TypeIndex int_type)
 /// Operation between two decimals leads to Decimal(P, S), where
 ///     P is one of (9, 18, 38, 76); equals to the maximum precision for the biggest underlying type of operands.
 ///     S is maximum scale of operands. The allowed valuas are [0, precision]
-template <typename T>
+template <is_decimal T>
 class DataTypeDecimalBase : public IDataType
 {
-    static_assert(IsDecimalNumber<T>);
-
 public:
     using FieldType = T;
     using ColumnType = ColumnDecimal<T>;

src/DataTypes/DataTypeEnum.cpp

@@ -134,7 +134,8 @@ Field DataTypeEnum<Type>::castToName(const Field & value_or_name) const
         return this->getNameForValue(static_cast<Type>(value)).toString();
     }
     else
-        throw Exception(String("DataTypeEnum: Unsupported type of field ") + value_or_name.getTypeName(), ErrorCodes::BAD_TYPE_OF_FIELD);
+        throw Exception(ErrorCodes::BAD_TYPE_OF_FIELD,
+            "DataTypeEnum: Unsupported type of field {}", value_or_name.getTypeName());
 }
 
 template <typename Type>
@@ -153,7 +154,8 @@ Field DataTypeEnum<Type>::castToValue(const Field & value_or_name) const
         return value;
     }
     else
-        throw Exception(String("DataTypeEnum: Unsupported type of field ") + value_or_name.getTypeName(), ErrorCodes::BAD_TYPE_OF_FIELD);
+        throw Exception(ErrorCodes::BAD_TYPE_OF_FIELD,
+            "DataTypeEnum: Unsupported type of field {}", value_or_name.getTypeName());
 }
 
 

src/DataTypes/DataTypeInterval.h

@@ -27,7 +27,7 @@ public:
 
     DataTypeInterval(IntervalKind kind_) : kind(kind_) {}
 
-    std::string doGetName() const override { return std::string("Interval") + kind.toString(); }
+    std::string doGetName() const override { return fmt::format("Interval{}", kind.toString()); }
     const char * getFamilyName() const override { return "Interval"; }
     TypeIndex getTypeId() const override { return TypeIndex::Interval; }
 

src/DataTypes/DataTypeNumberBase.cpp

@@ -28,13 +28,13 @@ MutableColumnPtr DataTypeNumberBase<T>::createColumn() const
 template <typename T>
 bool DataTypeNumberBase<T>::isValueRepresentedByInteger() const
 {
-    return is_integer_v<T>;
+    return is_integer<T>;
 }
 
 template <typename T>
 bool DataTypeNumberBase<T>::isValueRepresentedByUnsignedInteger() const
 {
-    return is_integer_v<T> && is_unsigned_v<T>;
+    return is_integer<T> && is_unsigned_v<T>;
 }
 
 

src/DataTypes/DataTypesDecimal.cpp

@@ -25,14 +25,14 @@ namespace ErrorCodes
 }
 
 
-template <typename T>
+template <is_decimal T>
 std::string DataTypeDecimal<T>::doGetName() const
 {
     return fmt::format("Decimal({}, {})", this->precision, this->scale);
 }
 
 
-template <typename T>
+template <is_decimal T>
 bool DataTypeDecimal<T>::equals(const IDataType & rhs) const
 {
     if (auto * ptype = typeid_cast<const DataTypeDecimal<T> *>(&rhs))
@@ -40,14 +40,14 @@ bool DataTypeDecimal<T>::equals(const IDataType & rhs) const
     return false;
 }
 
-template <typename T>
+template <is_decimal T>
 DataTypePtr DataTypeDecimal<T>::promoteNumericType() const
 {
     using PromotedType = DataTypeDecimal<Decimal128>;
     return std::make_shared<PromotedType>(PromotedType::maxPrecision(), this->scale);
 }
 
-template <typename T>
+template <is_decimal T>
 T DataTypeDecimal<T>::parseFromString(const String & str) const
 {
     ReadBufferFromMemory buf(str.data(), str.size());
@@ -61,7 +61,7 @@ T DataTypeDecimal<T>::parseFromString(const String & str) const
     return x;
 }
 
-template <typename T>
+template <is_decimal T>
 SerializationPtr DataTypeDecimal<T>::doGetDefaultSerialization() const
 {
     return std::make_shared<SerializationDecimal<T>>(this->precision, this->scale);

src/DataTypes/DataTypesDecimal.h

@@ -24,11 +24,10 @@ namespace ErrorCodes
 /// Operation between two decimals leads to Decimal(P, S), where
 ///     P is one of (9, 18, 38, 76); equals to the maximum precision for the biggest underlying type of operands.
 ///     S is maximum scale of operands. The allowed valuas are [0, precision]
-template <typename T>
+template <is_decimal T>
 class DataTypeDecimal final : public DataTypeDecimalBase<T>
 {
     using Base = DataTypeDecimalBase<T>;
-    static_assert(IsDecimalNumber<T>);
 
 public:
     using typename Base::FieldType;
@@ -48,6 +47,11 @@ public:
     SerializationPtr doGetDefaultSerialization() const override;
 };
 
+using DataTypeDecimal32 = DataTypeDecimal<Decimal32>;
+using DataTypeDecimal64 = DataTypeDecimal<Decimal64>;
+using DataTypeDecimal128 = DataTypeDecimal<Decimal128>;
+using DataTypeDecimal256 = DataTypeDecimal<Decimal256>;
+
 template <typename T>
 inline const DataTypeDecimal<T> * checkDecimal(const IDataType & data_type)
 {

src/DataTypes/IDataType.h

@@ -4,7 +4,7 @@
 #include <Common/COW.h>
 #include <boost/noncopyable.hpp>
 #include <Core/Names.h>
-#include <Core/Types.h>
+#include <Core/TypeId.h>
 #include <DataTypes/DataTypeCustom.h>
 
 
@@ -490,7 +490,7 @@ template <typename DataType> constexpr bool IsDataTypeDateOrDateTime = false;
 
 template <typename DataType> constexpr bool IsDataTypeDecimalOrNumber = IsDataTypeDecimal<DataType> || IsDataTypeNumber<DataType>;
 
-template <typename T>
+template <is_decimal T>
 class DataTypeDecimal;
 
 template <typename T>
@@ -501,7 +501,7 @@ class DataTypeDate32;
 class DataTypeDateTime;
 class DataTypeDateTime64;
 
-template <typename T> constexpr bool IsDataTypeDecimal<DataTypeDecimal<T>> = true;
+template <is_decimal T> constexpr bool IsDataTypeDecimal<DataTypeDecimal<T>> = true;
 template <> inline constexpr bool IsDataTypeDecimal<DataTypeDateTime64> = true;
 
 template <typename T> constexpr bool IsDataTypeNumber<DataTypeNumber<T>> = true;

src/DataTypes/NumberTraits.h

@@ -172,14 +172,14 @@ template <typename A, typename B>
 struct ResultOfIf
 {
     static constexpr bool has_float = std::is_floating_point_v<A> || std::is_floating_point_v<B>;
-    static constexpr bool has_integer = is_integer_v<A> || is_integer_v<B>;
+    static constexpr bool has_integer = is_integer<A> || is_integer<B>;
     static constexpr bool has_signed = is_signed_v<A> || is_signed_v<B>;
     static constexpr bool has_unsigned = !is_signed_v<A> || !is_signed_v<B>;
     static constexpr bool has_big_int = is_big_int_v<A> || is_big_int_v<B>;
 
     static constexpr size_t max_size_of_unsigned_integer = max(is_signed_v<A> ? 0 : sizeof(A), is_signed_v<B> ? 0 : sizeof(B));
     static constexpr size_t max_size_of_signed_integer = max(is_signed_v<A> ? sizeof(A) : 0, is_signed_v<B> ? sizeof(B) : 0);
-    static constexpr size_t max_size_of_integer = max(is_integer_v<A> ? sizeof(A) : 0, is_integer_v<B> ? sizeof(B) : 0);
+    static constexpr size_t max_size_of_integer = max(is_integer<A> ? sizeof(A) : 0, is_integer<B> ? sizeof(B) : 0);
     static constexpr size_t max_size_of_float = max(std::is_floating_point_v<A> ? sizeof(A) : 0, std::is_floating_point_v<B> ? sizeof(B) : 0);
 
     using ConstructedType = typename Construct<has_signed, has_float,
@@ -190,9 +190,9 @@ struct ResultOfIf
 
     using Type =
         std::conditional_t<std::is_same_v<A, B>, A,
-        std::conditional_t<IsDecimalNumber<A> && IsDecimalNumber<B>,
+        std::conditional_t<is_decimal<A> && is_decimal<B>,
             std::conditional_t<(sizeof(A) > sizeof(B)), A, B>,
-        std::conditional_t<!IsDecimalNumber<A> && !IsDecimalNumber<B>,
+        std::conditional_t<!is_decimal<A> && !is_decimal<B>,
             ConstructedType, Error>>>;
 };
 

src/DataTypes/Serializations/SerializationNumber.cpp

@@ -25,7 +25,7 @@ void SerializationNumber<T>::deserializeText(IColumn & column, ReadBuffer & istr
 {
     T x;
 
-    if constexpr (is_integer_v<T> && is_arithmetic_v<T>)
+    if constexpr (is_integer<T> && is_arithmetic_v<T>)
         readIntTextUnsafe(x, istr);
     else
         readText(x, istr);

src/DataTypes/registerDataTypeDateTime.cpp

@@ -26,10 +26,8 @@ String getExceptionMessage(
     const String & message, size_t argument_index, const char * argument_name,
     const std::string & context_data_type_name, Field::Types::Which field_type)
 {
-    return std::string("Parameter #") + std::to_string(argument_index) + " '"
+    return fmt::format("Parameter #{} '{}' for {}{}, expected {} literal",
-           + argument_name + "' for " + context_data_type_name
+        argument_index, argument_name, context_data_type_name, message, field_type);
-           + message
-           + ", expected: " + Field::Types::toString(field_type) + " literal.";
 }
 
 template <typename T, ArgumentKind Kind>
@@ -49,7 +47,7 @@ getArgument(const ASTPtr & arguments, size_t argument_index, const char * argume
         else
         {
             if (argument && argument->value.getType() != field_type)
-                throw Exception(getExceptionMessage(String(" has wrong type: ") + argument->value.getTypeName(),
+                throw Exception(getExceptionMessage(fmt::format(" has wrong type: {}", argument->value.getTypeName()),
                     argument_index, argument_name, context_data_type_name, field_type), ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
             else
                 throw Exception(getExceptionMessage(" is missing", argument_index, argument_name, context_data_type_name, field_type),

src/Dictionaries/DictionaryHelpers.h

@@ -240,8 +240,7 @@ public:
     using ColumnType =
         std::conditional_t<std::is_same_v<DictionaryAttributeType, Array>, ColumnArray,
             std::conditional_t<std::is_same_v<DictionaryAttributeType, String>, ColumnString,
-                std::conditional_t<IsDecimalNumber<DictionaryAttributeType>, ColumnDecimal<DictionaryAttributeType>,
+                ColumnVectorOrDecimal<DictionaryAttributeType>>>;
-                    ColumnVector<DictionaryAttributeType>>>>;
 
     using ColumnPtr = typename ColumnType::MutablePtr;
 
@@ -267,7 +266,7 @@ public:
         {
             return ColumnType::create(size);
         }
-        else if constexpr (IsDecimalNumber<DictionaryAttributeType>)
+        else if constexpr (is_decimal<DictionaryAttributeType>)
         {
             auto nested_type = removeNullable(dictionary_attribute.type);
             auto scale = getDecimalScale(*nested_type);

src/Dictionaries/DictionaryStructure.cpp

@@ -19,16 +19,15 @@ namespace DB
 namespace ErrorCodes
 {
     extern const int UNKNOWN_TYPE;
-    extern const int ARGUMENT_OUT_OF_BOUND;
     extern const int TYPE_MISMATCH;
     extern const int BAD_ARGUMENTS;
 }
 
 namespace
 {
-    DictionaryTypedSpecialAttribute makeDictionaryTypedSpecialAttribute(
+DictionaryTypedSpecialAttribute makeDictionaryTypedSpecialAttribute(
     const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix, const std::string & default_type)
-    {
+{
     const auto name = config.getString(config_prefix + ".name", "");
     const auto expression = config.getString(config_prefix + ".expression", "");
 
@@ -37,66 +36,20 @@ namespace
 
     const auto type_name = config.getString(config_prefix + ".type", default_type);
     return DictionaryTypedSpecialAttribute{std::move(name), std::move(expression), DataTypeFactory::instance().get(type_name)};
-    }
-
 }
 
-
+std::optional<AttributeUnderlyingType> maybeGetAttributeUnderlyingType(TypeIndex index)
-AttributeUnderlyingType getAttributeUnderlyingType(const DataTypePtr & type)
 {
-    auto type_index = type->getTypeId();
+    switch (index) /// Special cases which do not map TypeIndex::T -> AttributeUnderlyingType::T
-
-    switch (type_index)
     {
-        case TypeIndex::UInt8:          return AttributeUnderlyingType::UInt8;
-        case TypeIndex::UInt16:         return AttributeUnderlyingType::UInt16;
-        case TypeIndex::UInt32:         return AttributeUnderlyingType::UInt32;
-        case TypeIndex::UInt64:         return AttributeUnderlyingType::UInt64;
-        case TypeIndex::UInt128:        return AttributeUnderlyingType::UInt128;
-        case TypeIndex::UInt256:        return AttributeUnderlyingType::UInt256;
-
-        case TypeIndex::Int8:           return AttributeUnderlyingType::Int8;
-        case TypeIndex::Int16:          return AttributeUnderlyingType::Int16;
-        case TypeIndex::Int32:          return AttributeUnderlyingType::Int32;
-        case TypeIndex::Int64:          return AttributeUnderlyingType::Int64;
-        case TypeIndex::Int128:         return AttributeUnderlyingType::Int128;
-        case TypeIndex::Int256:         return AttributeUnderlyingType::Int256;
-
-        case TypeIndex::Float32:        return AttributeUnderlyingType::Float32;
-        case TypeIndex::Float64:        return AttributeUnderlyingType::Float64;
-
-        case TypeIndex::Decimal32:      return AttributeUnderlyingType::Decimal32;
-        case TypeIndex::Decimal64:      return AttributeUnderlyingType::Decimal64;
-        case TypeIndex::Decimal128:     return AttributeUnderlyingType::Decimal128;
-        case TypeIndex::Decimal256:     return AttributeUnderlyingType::Decimal256;
-
         case TypeIndex::Date:       return AttributeUnderlyingType::UInt16;
         case TypeIndex::DateTime:   return AttributeUnderlyingType::UInt32;
         case TypeIndex::DateTime64: return AttributeUnderlyingType::UInt64;
-
-        case TypeIndex::UUID:           return AttributeUnderlyingType::UUID;
-
-        case TypeIndex::String:         return AttributeUnderlyingType::String;
-
-        case TypeIndex::Array:          return AttributeUnderlyingType::Array;
-
         default: break;
     }
 
-    throw Exception(ErrorCodes::UNKNOWN_TYPE, "Unknown type {} for dictionary attribute", type->getName());
+    return magic_enum::enum_cast<AttributeUnderlyingType>(static_cast<TypeIndexUnderlying>(index));
 }
-
-
-std::string toString(AttributeUnderlyingType type)
-{
-    switch (type)
-    {
-#define M(TYPE) case AttributeUnderlyingType::TYPE: return #TYPE;
-    FOR_ATTRIBUTE_TYPES(M)
-#undef M
-    }
-
-    throw Exception(ErrorCodes::ARGUMENT_OUT_OF_BOUND, "Unknown dictionary attribute type {}", toString(static_cast<int>(type)));
 }
 
 
@@ -152,7 +105,7 @@ DictionaryStructure::DictionaryStructure(const Poco::Util::AbstractConfiguration
             if (id && attribute.underlying_type != AttributeUnderlyingType::UInt64)
                 throw Exception(ErrorCodes::TYPE_MISMATCH,
                     "Hierarchical attribute type for dictionary with simple key must be UInt64. Actual {}",
-                    toString(attribute.underlying_type));
+                    attribute.underlying_type);
 
             else if (key)
                 throw Exception(ErrorCodes::BAD_ARGUMENTS, "Dictionary with complex key does not support hierarchy");
@@ -342,7 +295,12 @@ std::vector<DictionaryAttribute> DictionaryStructure::getAttributes(
         bool is_nullable = initial_type->isNullable();
 
         auto non_nullable_type = removeNullable(initial_type);
-        const auto underlying_type = getAttributeUnderlyingType(non_nullable_type);
+
+        const auto underlying_type_opt = maybeGetAttributeUnderlyingType(non_nullable_type->getTypeId());
+
+        if (!underlying_type_opt)
+            throw Exception(ErrorCodes::UNKNOWN_TYPE,
+                "Unknown type {} for dictionary attribute", non_nullable_type->getName());
 
         const auto expression = config.getString(prefix + "expression", "");
         if (!expression.empty())
@@ -391,7 +349,7 @@ std::vector<DictionaryAttribute> DictionaryStructure::getAttributes(
 
         res_attributes.emplace_back(DictionaryAttribute{
             name,
-            underlying_type,
+            *underlying_type_opt,
             initial_type,
             initial_type_serialization,
             expression,

src/Dictionaries/DictionaryStructure.h

@@ -11,53 +11,37 @@
 #include <IO/ReadBufferFromString.h>
 #include <DataTypes/IDataType.h>
 #include <Interpreters/IExternalLoadable.h>
+#include <common/EnumReflection.h>
+#include <Core/TypeId.h>
 
 #if defined(__GNUC__)
     /// GCC mistakenly warns about the names in enum class.
     #pragma GCC diagnostic ignored "-Wshadow"
 #endif
 
-
-#define FOR_ATTRIBUTE_TYPES(M) \
-    M(UInt8) \
-    M(UInt16) \
-    M(UInt32) \
-    M(UInt64) \
-    M(UInt128) \
-    M(UInt256) \
-    M(Int8) \
-    M(Int16) \
-    M(Int32) \
-    M(Int64) \
-    M(Int128) \
-    M(Int256) \
-    M(Float32) \
-    M(Float64) \
-    M(Decimal32) \
-    M(Decimal64) \
-    M(Decimal128) \
-    M(Decimal256) \
-    M(UUID) \
-    M(String) \
-    M(Array) \
-
-
 namespace DB
 {
+using TypeIndexUnderlying = magic_enum::underlying_type_t<TypeIndex>;
 
-enum class AttributeUnderlyingType
+// We need to be able to map TypeIndex -> AttributeUnderlyingType and AttributeUnderlyingType -> real type
+// The first can be done by defining AttributeUnderlyingType enum values to TypeIndex values and then performing
+// a enum_cast.
+// The second can be achieved by using ReverseTypeId
+#define map_item(__T) __T = static_cast<TypeIndexUnderlying>(TypeIndex::__T)
+
+enum class AttributeUnderlyingType : TypeIndexUnderlying
 {
-#define M(TYPE) TYPE,
+    map_item(Int8), map_item(Int16), map_item(Int32), map_item(Int64), map_item(Int128), map_item(Int256),
-    FOR_ATTRIBUTE_TYPES(M)
+    map_item(UInt8), map_item(UInt16), map_item(UInt32), map_item(UInt64), map_item(UInt128), map_item(UInt256),
-#undef M
+    map_item(Float32), map_item(Float64),
+    map_item(Decimal32), map_item(Decimal64), map_item(Decimal128), map_item(Decimal256),
+
+    map_item(UUID), map_item(String), map_item(Array)
 };
 
+#undef map_item
 
-AttributeUnderlyingType getAttributeUnderlyingType(const std::string & type);
+/// Min and max lifetimes for a dictionary or its entry
-
-std::string toString(AttributeUnderlyingType type);
-
-/// Min and max lifetimes for a dictionary or it's entry
 using DictionaryLifetime = ExternalLoadableLifetime;
 
 /** Holds the description of a single dictionary attribute:
@@ -85,24 +69,23 @@ struct DictionaryAttribute final
     const bool is_nullable;
 };
 
-template <typename Type>
+template <AttributeUnderlyingType type>
 struct DictionaryAttributeType
 {
-    using AttributeType = Type;
+    /// Converts @c type to it underlying type e.g. AttributeUnderlyingType::UInt8 -> UInt8
+    using AttributeType = ReverseTypeId<
+        static_cast<TypeIndex>(
+            static_cast<TypeIndexUnderlying>(type))>;
 };
 
 template <typename F>
-void callOnDictionaryAttributeType(AttributeUnderlyingType type, F && func)
+constexpr void callOnDictionaryAttributeType(AttributeUnderlyingType type, F && func)
 {
-    switch (type)
+    static_for<AttributeUnderlyingType>([type, func = std::forward<F>(func)](auto other)
     {
-#define M(TYPE) \
+        if (type == other)
-        case AttributeUnderlyingType::TYPE: \
+            func(DictionaryAttributeType<other>{});
-            func(DictionaryAttributeType<TYPE>()); \
+    });
-            break;
-    FOR_ATTRIBUTE_TYPES(M)
-#undef M
-    }
 };
 
 struct DictionarySpecialAttribute final

src/Disks/IVolume.cpp

@@ -12,23 +12,6 @@ namespace ErrorCodes
     extern const int NO_ELEMENTS_IN_CONFIG;
     extern const int INCONSISTENT_RESERVATIONS;
     extern const int NO_RESERVATIONS_PROVIDED;
-    extern const int UNKNOWN_VOLUME_TYPE;
-}
-
-String volumeTypeToString(VolumeType type)
-{
-    switch (type)
-    {
-        case VolumeType::JBOD:
-            return "JBOD";
-        case VolumeType::RAID1:
-            return "RAID1";
-        case VolumeType::SINGLE_DISK:
-            return "SINGLE_DISK";
-        case VolumeType::UNKNOWN:
-            return "UNKNOWN";
-    }
-    throw Exception("Unknown volume type, please add it to DB::volumeTypeToString", ErrorCodes::UNKNOWN_VOLUME_TYPE);
 }
 
 IVolume::IVolume(

src/Disks/IVolume.h

@@ -16,8 +16,6 @@ enum class VolumeType
     UNKNOWN
 };
 
-String volumeTypeToString(VolumeType t);
-
 class IVolume;
 using VolumePtr = std::shared_ptr<IVolume>;
 using Volumes = std::vector<VolumePtr>;

src/Functions/DivisionUtils.h

@@ -81,7 +81,7 @@ struct DivideIntegralImpl
 
         /// Otherwise overflow may occur due to integer promotion. Example: int8_t(-1) / uint64_t(2).
         /// NOTE: overflow is still possible when dividing large signed number to large unsigned number or vice-versa. But it's less harmful.
-        if constexpr (is_integer_v<A> && is_integer_v<B> && (is_signed_v<A> || is_signed_v<B>))
+        if constexpr (is_integer<A> && is_integer<B> && (is_signed_v<A> || is_signed_v<B>))
         {
             using SignedCastA = make_signed_t<CastA>;
             using SignedCastB = std::conditional_t<sizeof(A) <= sizeof(B), make_signed_t<CastB>, SignedCastA>;

src/Functions/FunctionBinaryArithmetic.h

@@ -33,6 +33,7 @@
 #include <Common/typeid_cast.h>
 #include <Common/assert_cast.h>
 #include <Common/FieldVisitorsAccurateComparison.h>
+#include <Common/TypeList.h>
 #include <common/map.h>
 
 #if !defined(ARCADIA_BUILD)
@@ -183,14 +184,8 @@ namespace impl_
 
 enum class OpCase { Vector, LeftConstant, RightConstant };
 
-template <class T>
+constexpr const auto & undec(const auto & x) { return x; }
-inline constexpr const auto & undec(const T & x)
+constexpr const auto & undec(const is_decimal auto & x) { return x.value; }
-{
-    if constexpr (IsDecimalNumber<T>)
-        return x.value;
-    else
-        return x;
-}
 
 template <typename A, typename B, typename Op, typename OpResultType = typename Op::ResultType>
 struct BinaryOperation
@@ -301,19 +296,17 @@ struct DecimalBinaryOperation
 {
 private:
     using ResultType = OpResultType; // e.g. Decimal32
-    using NativeResultType = typename NativeType<ResultType>::Type; // e.g. UInt32 for Decimal32
+    using NativeResultType = NativeType<ResultType>; // e.g. UInt32 for Decimal32
 
-    using ResultContainerType = typename std::conditional_t<IsDecimalNumber<ResultType>,
+    using ResultContainerType = typename ColumnVectorOrDecimal<ResultType>::Container;
-        ColumnDecimal<ResultType>,
-        ColumnVector<ResultType>>::Container;
 
 public:
-    template <OpCase op_case, bool is_decimal_a, bool is_decimal_b, class A, class B>
+    template <OpCase op_case, bool is_decimal_a, bool is_decimal_b>
-    static void NO_INLINE process(const A & a, const B & b, ResultContainerType & c,
+    static void NO_INLINE process(const auto & a, const auto & b, ResultContainerType & c,
         NativeResultType scale_a, NativeResultType scale_b)
     {
-        if constexpr (op_case == OpCase::LeftConstant) static_assert(!IsDecimalNumber<A>);
+        if constexpr (op_case == OpCase::LeftConstant) static_assert(!is_decimal<decltype(a)>);
-        if constexpr (op_case == OpCase::RightConstant) static_assert(!IsDecimalNumber<B>);
+        if constexpr (op_case == OpCase::RightConstant) static_assert(!is_decimal<decltype(b)>);
 
         size_t size;
 
@@ -383,10 +376,8 @@ public:
 
     template <bool is_decimal_a, bool is_decimal_b, class A, class B>
     static ResultType process(A a, B b, NativeResultType scale_a, NativeResultType scale_b)
+        requires(!is_decimal<A> && !is_decimal<B>)
     {
-        static_assert(!IsDecimalNumber<A>);
-        static_assert(!IsDecimalNumber<B>);
-
         if constexpr (is_division && is_decimal_b)
             return applyScaledDiv<is_decimal_a>(a, b, scale_a);
         else if constexpr (is_plus_minus_compare)
@@ -516,64 +507,26 @@ class FunctionBinaryArithmetic : public IFunction
     ContextPtr context;
     bool check_decimal_overflow = true;
 
-    template <typename F>
+    static bool castType(const IDataType * type, auto && f)
-    static bool castType(const IDataType * type, F && f)
     {
-        return castTypeToEither<
+        using Types = TypeList<
-            DataTypeUInt8,
+            DataTypeUInt8, DataTypeUInt16, DataTypeUInt32, DataTypeUInt64, DataTypeUInt128, DataTypeUInt256,
-            DataTypeUInt16,
+            DataTypeInt8, DataTypeInt16, DataTypeInt32, DataTypeInt64, DataTypeInt128, DataTypeInt256,
-            DataTypeUInt32,
+            DataTypeDecimal32, DataTypeDecimal64, DataTypeDecimal128, DataTypeDecimal256,
-            DataTypeUInt64,
+            DataTypeDate, DataTypeDateTime,
-            DataTypeUInt128,
+            DataTypeFixedString>;
-            DataTypeUInt256,
-            DataTypeInt8,
-            DataTypeInt16,
-            DataTypeInt32,
-            DataTypeInt64,
-            DataTypeInt128,
-            DataTypeInt256,
-            DataTypeFloat32,
-            DataTypeFloat64,
-            DataTypeDate,
-            DataTypeDateTime,
-            DataTypeDecimal<Decimal32>,
-            DataTypeDecimal<Decimal64>,
-            DataTypeDecimal<Decimal128>,
-            DataTypeDecimal<Decimal256>,
-            DataTypeFixedString
-        >(type, std::forward<F>(f));
-    }
 
-    template <typename F>
+        using Floats = TypeList<DataTypeFloat32, DataTypeFloat64>;
-    static bool castTypeNoFloats(const IDataType * type, F && f)
+
-    {
+        using ValidTypes = std::conditional_t<valid_on_float_arguments,
-        return castTypeToEither<
+            typename TypeListConcat<Types, Floats>::Type,
-            DataTypeUInt8,
+            Types>;
-            DataTypeUInt16,
+
-            DataTypeUInt32,
+        return castTypeToEitherTL<ValidTypes>(type, std::forward<decltype(f)>(f));
-            DataTypeUInt64,
-            DataTypeUInt128,
-            DataTypeUInt256,
-            DataTypeInt8,
-            DataTypeInt16,
-            DataTypeInt32,
-            DataTypeInt64,
-            DataTypeInt128,
-            DataTypeInt256,
-            DataTypeDate,
-            DataTypeDateTime,
-            DataTypeDecimal<Decimal32>,
-            DataTypeDecimal<Decimal64>,
-            DataTypeDecimal<Decimal128>,
-            DataTypeDecimal<Decimal256>,
-            DataTypeFixedString
-        >(type, std::forward<F>(f));
     }
 
     template <typename F>
     static bool castBothTypes(const IDataType * left, const IDataType * right, F && f)
-    {
-        if constexpr (valid_on_float_arguments)
     {
         return castType(left, [&](const auto & left_)
         {
@@ -583,17 +536,6 @@ class FunctionBinaryArithmetic : public IFunction
             });
         });
     }
-        else
-        {
-            return castTypeNoFloats(left, [&](const auto & left_)
-            {
-                return castTypeNoFloats(right, [&](const auto & right_)
-                {
-                    return f(left_, right_);
-                });
-            });
-        }
-    }
 
     static FunctionOverloadResolverPtr
     getFunctionForIntervalArithmetic(const DataTypePtr & type0, const DataTypePtr & type1, ContextPtr context)
@@ -632,7 +574,9 @@ class FunctionBinaryArithmetic : public IFunction
         std::string function_name;
         if (interval_data_type)
         {
-            function_name = String(is_plus ? "add" : "subtract") + interval_data_type->getKind().toString() + 's';
+            function_name = fmt::format("{}{}s",
+                is_plus ? "add" : "subtract",
+                interval_data_type->getKind().toString());
         }
         else
         {
@@ -785,23 +729,22 @@ class FunctionBinaryArithmetic : public IFunction
         return function->execute(new_arguments, result_type, input_rows_count);
     }
 
-    template <typename T, typename ResultDataType, typename CC, typename C>
+    template <typename T, typename ResultDataType>
-    static auto helperGetOrConvert(const CC & col_const, const C & col)
+    static auto helperGetOrConvert(const auto & col_const, const auto & col)
     {
         using ResultType = typename ResultDataType::FieldType;
-        using NativeResultType = typename NativeType<ResultType>::Type;
+        using NativeResultType = NativeType<ResultType>;
 
-        if constexpr (IsFloatingPoint<ResultDataType> && IsDecimalNumber<T>)
+        if constexpr (IsFloatingPoint<ResultDataType> && is_decimal<T>)
             return DecimalUtils::convertTo<NativeResultType>(col_const->template getValue<T>(), col.getScale());
-        else if constexpr (IsDecimalNumber<T>)
+        else if constexpr (is_decimal<T>)
             return col_const->template getValue<T>().value;
         else
             return col_const->template getValue<T>();
     }
 
-    template <OpCase op_case, bool left_decimal, bool right_decimal, typename OpImpl, typename OpImplCheck,
+    template <OpCase op_case, bool left_decimal, bool right_decimal, typename OpImpl, typename OpImplCheck>
-              typename L, typename R, typename VR, typename SA, typename SB>
+    void helperInvokeEither(const auto& left, const auto& right, auto& vec_res, auto scale_a, auto scale_b) const
-    void helperInvokeEither(const L& left, const R& right, VR& vec_res, SA scale_a, SB scale_b) const
     {
         if (check_decimal_overflow)
             OpImplCheck::template process<op_case, left_decimal, right_decimal>(left, right, vec_res, scale_a, scale_b);
@@ -809,27 +752,25 @@ class FunctionBinaryArithmetic : public IFunction
             OpImpl::template process<op_case, left_decimal, right_decimal>(left, right, vec_res, scale_a, scale_b);
     }
 
-    template <class LeftDataType, class RightDataType, class ResultDataType,
+    template <class LeftDataType, class RightDataType, class ResultDataType>
-              class L, class R, class CL, class CR>
     ColumnPtr executeNumericWithDecimal(
-        const L & left, const R & right,
+        const auto & left, const auto & right,
         const ColumnConst * const col_left_const, const ColumnConst * const col_right_const,
-        const CL * const col_left, const CR * const col_right,
+        const auto * const col_left, const auto * const col_right,
         size_t col_left_size) const
     {
         using T0 = typename LeftDataType::FieldType;
         using T1 = typename RightDataType::FieldType;
         using ResultType = typename ResultDataType::FieldType;
 
-        using NativeResultType = typename NativeType<ResultType>::Type;
+        using NativeResultType = NativeType<ResultType>;
         using OpImpl = DecimalBinaryOperation<Op, ResultType, false>;
         using OpImplCheck = DecimalBinaryOperation<Op, ResultType, true>;
 
-        using ColVecResult = std::conditional_t<IsDecimalNumber<ResultType>,
+        using ColVecResult = ColumnVectorOrDecimal<ResultType>;
-            ColumnDecimal<ResultType>, ColumnVector<ResultType>>;
 
-        static constexpr const bool left_is_decimal = IsDecimalNumber<T0>;
+        static constexpr const bool left_is_decimal = is_decimal<T0>;
-        static constexpr const bool right_is_decimal = IsDecimalNumber<T1>;
+        static constexpr const bool right_is_decimal = is_decimal<T1>;
         static constexpr const bool result_is_decimal = IsDataTypeDecimal<ResultDataType>;
 
         typename ColVecResult::MutablePtr col_res = nullptr;
@@ -1176,9 +1117,9 @@ public:
             using T0 = typename LeftDataType::FieldType;
             using T1 = typename RightDataType::FieldType;
             using ResultType = typename ResultDataType::FieldType;
-            using ColVecT0 = std::conditional_t<IsDecimalNumber<T0>, ColumnDecimal<T0>, ColumnVector<T0>>;
+            using ColVecT0 = ColumnVectorOrDecimal<T0>;
-            using ColVecT1 = std::conditional_t<IsDecimalNumber<T1>, ColumnDecimal<T1>, ColumnVector<T1>>;
+            using ColVecT1 = ColumnVectorOrDecimal<T1>;
-            using ColVecResult = std::conditional_t<IsDecimalNumber<ResultType>, ColumnDecimal<ResultType>, ColumnVector<ResultType>>;
+            using ColVecResult = ColumnVectorOrDecimal<ResultType>;
 
             const auto * const col_left_raw = arguments[0].column.get();
             const auto * const col_right_raw = arguments[1].column.get();

src/Functions/FunctionHelpers.h

@@ -68,13 +68,13 @@ const ColumnConst * checkAndGetColumnConstStringOrFixedString(const IColumn * co
 
 /// Transform anything to Field.
 template <typename T>
-inline std::enable_if_t<!IsDecimalNumber<T>, Field> toField(const T & x)
+Field toField(const T & x)
 {
     return Field(NearestFieldType<T>(x));
 }
 
-template <typename T>
+template <is_decimal T>
-inline std::enable_if_t<IsDecimalNumber<T>, Field> toField(const T & x, UInt32 scale)
+Field toField(const T & x, UInt32 scale)
 {
     return Field(NearestFieldType<T>(x, scale));
 }

src/Functions/FunctionMathUnary.h

@@ -150,7 +150,7 @@ private:
             using Types = std::decay_t<decltype(types)>;
             using Type = typename Types::RightType;
             using ReturnType = std::conditional_t<Impl::always_returns_float64 || !std::is_floating_point_v<Type>, Float64, Type>;
-            using ColVecType = std::conditional_t<IsDecimalNumber<Type>, ColumnDecimal<Type>, ColumnVector<Type>>;
+            using ColVecType = ColumnVectorOrDecimal<Type>;
 
             const auto col_vec = checkAndGetColumn<ColVecType>(col.column.get());
             return (res = execute<Type, ReturnType>(col_vec)) != nullptr;

src/Functions/FunctionUnaryArithmetic.h

@@ -38,8 +38,8 @@ template <typename A, typename Op>
 struct UnaryOperationImpl
 {
     using ResultType = typename Op::ResultType;
-    using ColVecA = std::conditional_t<IsDecimalNumber<A>, ColumnDecimal<A>, ColumnVector<A>>;
+    using ColVecA = ColumnVectorOrDecimal<A>;
-    using ColVecC = std::conditional_t<IsDecimalNumber<ResultType>, ColumnDecimal<ResultType>, ColumnVector<ResultType>>;
+    using ColVecC = ColumnVectorOrDecimal<ResultType>;
     using ArrayA = typename ColVecA::Container;
     using ArrayC = typename ColVecC::Container;
 

src/Functions/FunctionsConsistentHashing.h

@@ -106,8 +106,9 @@ private:
         else if (buckets_field.getType() == Field::Types::UInt64)
             num_buckets = checkBucketsRange(buckets_field.get<UInt64>());
         else
-            throw Exception("Illegal type " + String(buckets_field.getTypeName()) + " of the second argument of function " + getName(),
+            throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
-                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+                "Illegal type {} of the second argument of function {}",
+                buckets_field.getTypeName(), getName());
 
         const auto & hash_col = arguments[0].column;
         const IDataType * hash_type = arguments[0].type.get();

src/Functions/FunctionsConversion.h

@@ -764,7 +764,7 @@ template <typename FromDataType, typename Name>
 struct ConvertImpl<FromDataType, std::enable_if_t<!std::is_same_v<FromDataType, DataTypeString>, DataTypeString>, Name, ConvertDefaultBehaviorTag>
 {
     using FromFieldType = typename FromDataType::FieldType;
-    using ColVecType = std::conditional_t<IsDecimalNumber<FromFieldType>, ColumnDecimal<FromFieldType>, ColumnVector<FromFieldType>>;
+    using ColVecType = ColumnVectorOrDecimal<FromFieldType>;
 
     static ColumnPtr execute(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/)
     {
@@ -1699,9 +1699,9 @@ private:
                 using RightT = typename RightDataType::FieldType;
 
                 static constexpr bool bad_left =
-                    IsDecimalNumber<LeftT> || std::is_floating_point_v<LeftT> || is_big_int_v<LeftT> || is_signed_v<LeftT>;
+                    is_decimal<LeftT> || std::is_floating_point_v<LeftT> || is_big_int_v<LeftT> || is_signed_v<LeftT>;
                 static constexpr bool bad_right =
-                    IsDecimalNumber<RightT> || std::is_floating_point_v<RightT> || is_big_int_v<RightT> || is_signed_v<RightT>;
+                    is_decimal<RightT> || std::is_floating_point_v<RightT> || is_big_int_v<RightT> || is_signed_v<RightT>;
 
                 /// Disallow int vs UUID conversion (but support int vs UInt128 conversion)
                 if constexpr ((bad_left && std::is_same_v<RightDataType, DataTypeUUID>) ||
@@ -2585,8 +2585,9 @@ private:
                 }
                 else
                 {
-                    throw Exception{"Conversion from " + std::string(getTypeName(from_type_index)) + " to " + to_type->getName() + " is not supported",
+                    throw Exception(ErrorCodes::CANNOT_CONVERT_TYPE,
-                        ErrorCodes::CANNOT_CONVERT_TYPE};
+                        "Conversion from {} to {} is not supported",
+                        from_type_index, to_type->getName());
                 }
             }
 
@@ -2695,8 +2696,9 @@ private:
                     return nullable_column_wrapper(arguments, result_type, column_nullable, input_rows_count);
                 }
                 else
-                    throw Exception{"Conversion from " + std::string(getTypeName(type_index)) + " to " + to_type->getName() + " is not supported",
+                    throw Exception(ErrorCodes::CANNOT_CONVERT_TYPE,
-                        ErrorCodes::CANNOT_CONVERT_TYPE};
+                        "Conversion from {} to {} is not supported",
+                        type_index, to_type->getName());
             }
 
             return result_column;

src/Functions/FunctionsHashing.h

@@ -635,7 +635,7 @@ private:
     template <typename FromType>
     ColumnPtr executeType(const ColumnsWithTypeAndName & arguments) const
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<FromType>, ColumnDecimal<FromType>, ColumnVector<FromType>>;
+        using ColVecType = ColumnVectorOrDecimal<FromType>;
 
         if (const ColVecType * col_from = checkAndGetColumn<ColVecType>(arguments[0].column.get()))
         {
@@ -762,7 +762,7 @@ private:
     template <typename FromType, bool first>
     void executeIntType(const IColumn * column, typename ColumnVector<ToType>::Container & vec_to) const
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<FromType>, ColumnDecimal<FromType>, ColumnVector<FromType>>;
+        using ColVecType = ColumnVectorOrDecimal<FromType>;
 
         if (const ColVecType * col_from = checkAndGetColumn<ColVecType>(column))
         {
@@ -819,7 +819,7 @@ private:
     template <typename FromType, bool first>
     void executeBigIntType(const IColumn * column, typename ColumnVector<ToType>::Container & vec_to) const
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<FromType>, ColumnDecimal<FromType>, ColumnVector<FromType>>;
+        using ColVecType = ColumnVectorOrDecimal<FromType>;
 
         if (const ColVecType * col_from = checkAndGetColumn<ColVecType>(column))
         {

src/Functions/FunctionsJSON.h

@@ -522,7 +522,7 @@ public:
             else if (!accurate::convertNumeric(element.getDouble(), value))
                 return false;
         }
-        else if (element.isBool() && is_integer_v<NumberType> && convert_bool_to_integer)
+        else if (element.isBool() && is_integer<NumberType> && convert_bool_to_integer)
         {
             value = static_cast<NumberType>(element.getBool());
         }

src/Functions/FunctionsRound.h

@@ -315,11 +315,11 @@ template <typename T, RoundingMode rounding_mode, ScaleMode scale_mode>
 struct FloatRoundingImpl
 {
 private:
-    static_assert(!IsDecimalNumber<T>);
+    static_assert(!is_decimal<T>);
 
     using Op = FloatRoundingComputation<T, rounding_mode, scale_mode>;
     using Data = std::array<T, Op::data_count>;
-    using ColumnType = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<T>, ColumnVector<T>>;
+    using ColumnType = ColumnVector<T>;
     using Container = typename ColumnType::Container;
 
 public:
@@ -413,12 +413,10 @@ public:
 };
 
 
-template <typename T, RoundingMode rounding_mode, TieBreakingMode tie_breaking_mode>
+template <is_decimal T, RoundingMode rounding_mode, TieBreakingMode tie_breaking_mode>
 class DecimalRoundingImpl
 {
 private:
-    static_assert(IsDecimalNumber<T>);
-
     using NativeType = typename T::NativeType;
     using Op = IntegerRoundingComputation<NativeType, rounding_mode, ScaleMode::Negative, tie_breaking_mode>;
     using Container = typename ColumnDecimal<T>::Container;
@@ -453,15 +451,16 @@ public:
 /** Select the appropriate processing algorithm depending on the scale.
   */
 template <typename T, RoundingMode rounding_mode, TieBreakingMode tie_breaking_mode>
-class Dispatcher
+struct Dispatcher
 {
     template <ScaleMode scale_mode>
     using FunctionRoundingImpl = std::conditional_t<std::is_floating_point_v<T>,
         FloatRoundingImpl<T, rounding_mode, scale_mode>,
         IntegerRoundingImpl<T, rounding_mode, scale_mode, tie_breaking_mode>>;
 
-    static ColumnPtr apply(const ColumnVector<T> * col, Scale scale_arg)
+    static ColumnPtr apply(const IColumn * col_general, Scale scale_arg)
     {
+        const auto * const col = checkAndGetColumn<ColumnVector<T>>(col_general);
         auto col_res = ColumnVector<T>::create();
 
         typename ColumnVector<T>::Container & vec_res = col_res->getData();
@@ -488,9 +487,15 @@ class Dispatcher
 
         return col_res;
     }
+};
 
-    static ColumnPtr apply(const ColumnDecimal<T> * col, Scale scale_arg)
+template <is_decimal T, RoundingMode rounding_mode, TieBreakingMode tie_breaking_mode>
+struct Dispatcher<T, rounding_mode, tie_breaking_mode>
+{
+public:
+    static ColumnPtr apply(const IColumn * col_general, Scale scale_arg)
     {
+        const auto * const col = checkAndGetColumn<ColumnDecimal<T>>(col_general);
         const typename ColumnDecimal<T>::Container & vec_src = col->getData();
 
         auto col_res = ColumnDecimal<T>::create(vec_src.size(), vec_src.getScale());
@@ -501,15 +506,6 @@ class Dispatcher
 
         return col_res;
     }
-
-public:
-    static ColumnPtr apply(const IColumn * column, Scale scale_arg)
-    {
-        if constexpr (is_arithmetic_v<T>)
-            return apply(checkAndGetColumn<ColumnVector<T>>(column), scale_arg);
-        else if constexpr (IsDecimalNumber<T>)
-            return apply(checkAndGetColumn<ColumnDecimal<T>>(column), scale_arg);
-    }
 };
 
 /** A template for functions that round the value of an input parameter of type

src/Functions/GatherUtils/Algorithms.h

@@ -34,7 +34,7 @@ void writeSlice(const NumericArraySlice<T> & slice, NumericArraySink<T> & sink)
 template <typename T, typename U>
 void writeSlice(const NumericArraySlice<T> & slice, NumericArraySink<U> & sink)
 {
-    using NativeU = typename NativeType<U>::Type;
+    using NativeU = NativeType<U>;
 
     sink.elements.resize(sink.current_offset + slice.size);
     for (size_t i = 0; i < slice.size; ++i)
@@ -42,9 +42,9 @@ void writeSlice(const NumericArraySlice<T> & slice, NumericArraySink<U> & sink)
         const auto & src = slice.data[i];
         auto & dst = sink.elements[sink.current_offset];
 
-        if constexpr (OverBigInt<T> || OverBigInt<U>)
+        if constexpr (is_over_big_int<T> || is_over_big_int<U>)
         {
-            if constexpr (IsDecimalNumber<T>)
+            if constexpr (is_decimal<T>)
                 dst = static_cast<NativeU>(src.value);
             else
                 dst = static_cast<NativeU>(src);
@@ -99,7 +99,7 @@ inline ALWAYS_INLINE void writeSlice(const NumericArraySlice<T> & slice, Generic
 {
     for (size_t i = 0; i < slice.size; ++i)
     {
-        if constexpr (IsDecimalNumber<T>)
+        if constexpr (is_decimal<T>)
         {
             DecimalField field(T(slice.data[i]), 0); /// TODO: Decimal scale
             sink.elements.insert(field);
@@ -558,9 +558,9 @@ bool sliceEqualElements(const NumericArraySlice<T> & first [[maybe_unused]],
                         size_t second_ind [[maybe_unused]])
 {
     /// TODO: Decimal scale
-    if constexpr (IsDecimalNumber<T> && IsDecimalNumber<U>)
+    if constexpr (is_decimal<T> && is_decimal<U>)
         return accurate::equalsOp(first.data[first_ind].value, second.data[second_ind].value);
-    else if constexpr (IsDecimalNumber<T> || IsDecimalNumber<U>)
+    else if constexpr (is_decimal<T> || is_decimal<U>)
         return false;
     else
         return accurate::equalsOp(first.data[first_ind], second.data[second_ind]);
@@ -588,7 +588,7 @@ bool insliceEqualElements(const NumericArraySlice<T> & first [[maybe_unused]],
                           size_t first_ind [[maybe_unused]],
                           size_t second_ind [[maybe_unused]])
 {
-    if constexpr (IsDecimalNumber<T>)
+    if constexpr (is_decimal<T>)
         return accurate::equalsOp(first.data[first_ind].value, first.data[second_ind].value);
     else
         return accurate::equalsOp(first.data[first_ind], first.data[second_ind]);

src/Functions/GatherUtils/Sinks.h

@@ -36,7 +36,7 @@ struct NullableValueSource;
 template <typename T>
 struct NumericArraySink : public ArraySinkImpl<NumericArraySink<T>>
 {
-    using ColVecType = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<T>, ColumnVector<T>>;
+    using ColVecType = ColumnVectorOrDecimal<T>;
     using CompatibleArraySource = NumericArraySource<T>;
     using CompatibleValueSource = NumericValueSource<T>;
 

src/Functions/GatherUtils/Sources.h

@@ -39,7 +39,7 @@ template <typename ArraySink> struct NullableArraySink;
 template <typename T>
 struct NumericArraySource : public ArraySourceImpl<NumericArraySource<T>>
 {
-    using ColVecType = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<T>, ColumnVector<T>>;
+    using ColVecType = ColumnVectorOrDecimal<T>;
     using Slice = NumericArraySlice<T>;
     using Column = ColumnArray;
 
@@ -720,7 +720,7 @@ template <typename T>
 struct NumericValueSource : ValueSourceImpl<NumericValueSource<T>>
 {
     using Slice = NumericValueSlice<T>;
-    using Column = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<T>, ColumnVector<T>>;
+    using Column = ColumnVectorOrDecimal<T>;
 
     using SinkType = NumericArraySink<T>;
 

src/Functions/GatherUtils/createArraySink.cpp

@@ -18,7 +18,7 @@ struct ArraySinkCreator<Type, Types...>
 {
     static std::unique_ptr<IArraySink> create(IColumn & values, ColumnArray::Offsets & offsets, size_t column_size)
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<Type>, ColumnDecimal<Type>, ColumnVector<Type>>;
+        using ColVecType = ColumnVectorOrDecimal<Type>;
 
         IColumn * not_null_values = &values;
         bool is_nullable = false;

src/Functions/GatherUtils/createArraySource.cpp

@@ -18,7 +18,7 @@ struct ArraySourceCreator<Type, Types...>
 {
     static std::unique_ptr<IArraySource> create(const ColumnArray & col, const NullMap * null_map, bool is_const, size_t total_rows)
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<Type>, ColumnDecimal<Type>, ColumnVector<Type>>;
+        using ColVecType = ColumnVectorOrDecimal<Type>;
 
         if (typeid_cast<const ColVecType *>(&col.getData()))
         {

src/Functions/GatherUtils/createValueSource.cpp

@@ -18,7 +18,7 @@ struct ValueSourceCreator<Type, Types...>
 {
     static std::unique_ptr<IValueSource> create(const IColumn & col, const NullMap * null_map, bool is_const, size_t total_rows)
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<Type>, ColumnDecimal<Type>, ColumnVector<Type>>;
+        using ColVecType = ColumnVectorOrDecimal<Type>;
 
         if (auto column_vector = typeid_cast<const ColVecType *>(&col))
         {

src/Functions/GregorianDate.h

@@ -38,14 +38,13 @@ namespace DB
           * integral type which should be at least 32 bits wide, and
           * should preferably signed.
           */
-        template <typename T, std::enable_if_t<is_integer_v<T>> * = nullptr>
+        GregorianDate(is_integer auto mjd);
-        GregorianDate(T mjd);
 
         /** Convert to Modified Julian Day. The type T is an integral type
           * which should be at least 32 bits wide, and should preferably
           * signed.
           */
-        template <typename T, std::enable_if_t<is_integer_v<T>> * = nullptr>
+        template <is_integer T>
         T toModifiedJulianDay() const;
 
         /** Write the date in text form 'YYYY-MM-DD' to a buffer.
@@ -90,14 +89,13 @@ namespace DB
           * integral type which should be at least 32 bits wide, and
           * should preferably signed.
           */
-        template <typename T, std::enable_if_t<is_integer_v<T>> * = nullptr>
+        OrdinalDate(is_integer auto mjd);
-        OrdinalDate(T mjd);
 
         /** Convert to Modified Julian Day. The type T is an integral
           * type which should be at least 32 bits wide, and should
           * preferably be signed.
           */
-        template <typename T, std::enable_if_t<is_integer_v<T>> * = nullptr>
+        template <is_integer T>
         T toModifiedJulianDay() const noexcept;
 
         YearT year() const noexcept
@@ -259,8 +257,7 @@ namespace DB
     }
 
     template <typename YearT>
-    template <typename T, std::enable_if_t<is_integer_v<T>> *>
+    GregorianDate<YearT>::GregorianDate(is_integer auto mjd)
-    GregorianDate<YearT>::GregorianDate(T mjd)
     {
         const OrdinalDate<YearT> ord(mjd);
         const MonthDay md(gd::is_leap_year(ord.year()), ord.dayOfYear());
@@ -270,7 +267,7 @@ namespace DB
     }
 
     template <typename YearT>
-    template <typename T, std::enable_if_t<is_integer_v<T>> *>
+    template <is_integer T>
     T GregorianDate<YearT>::toModifiedJulianDay() const
     {
         const MonthDay md(month_, day_of_month_);
@@ -332,8 +329,7 @@ namespace DB
     }
 
     template <typename YearT>
-    template <typename T, std::enable_if_t<is_integer_v<T>> *>
+    OrdinalDate<YearT>::OrdinalDate(is_integer auto mjd)
-    OrdinalDate<YearT>::OrdinalDate(T mjd)
     {
         const auto a         = mjd + 678575;
         const auto quad_cent = gd::div(a, 146097);
@@ -348,7 +344,7 @@ namespace DB
     }
 
     template <typename YearT>
-    template <typename T, std::enable_if_t<is_integer_v<T>> *>
+    template <is_integer T>
     T OrdinalDate<YearT>::toModifiedJulianDay() const noexcept
     {
         const auto y = year_ - 1;

src/Functions/abs.cpp

@@ -9,18 +9,18 @@ namespace DB
 template <typename A>
 struct AbsImpl
 {
-    using ResultType = std::conditional_t<IsDecimalNumber<A>, A, typename NumberTraits::ResultOfAbs<A>::Type>;
+    using ResultType = std::conditional_t<is_decimal<A>, A, typename NumberTraits::ResultOfAbs<A>::Type>;
     static const constexpr bool allow_fixed_string = false;
 
     static inline NO_SANITIZE_UNDEFINED ResultType apply(A a)
     {
-        if constexpr (IsDecimalNumber<A>)
+        if constexpr (is_decimal<A>)
             return a < A(0) ? A(-a) : a;
         else if constexpr (is_big_int_v<A> && is_signed_v<A>)
             return (a < 0) ? -a : a;
-        else if constexpr (is_integer_v<A> && is_signed_v<A>)
+        else if constexpr (is_integer<A> && is_signed_v<A>)
             return a < 0 ? static_cast<ResultType>(~a) + 1 : static_cast<ResultType>(a);
-        else if constexpr (is_integer_v<A> && is_unsigned_v<A>)
+        else if constexpr (is_integer<A> && is_unsigned_v<A>)
             return static_cast<ResultType>(a);
         else if constexpr (std::is_floating_point_v<A>)
             return static_cast<ResultType>(std::abs(a));

src/Functions/array/arrayAggregation.cpp

@@ -71,7 +71,7 @@ struct ArrayAggregateResultImpl<ArrayElement, AggregateOperation::sum>
         std::conditional_t<std::is_same_v<ArrayElement, UInt128>, UInt128,
         std::conditional_t<std::is_same_v<ArrayElement, Int256>, Int256,
         std::conditional_t<std::is_same_v<ArrayElement, UInt256>, UInt256,
-        std::conditional_t<IsDecimalNumber<ArrayElement>, Decimal128,
+        std::conditional_t<is_decimal<ArrayElement>, Decimal128,
         std::conditional_t<std::is_floating_point_v<ArrayElement>, Float64,
         std::conditional_t<std::is_signed_v<ArrayElement>, Int64,
             UInt64>>>>>>>;
@@ -135,8 +135,8 @@ struct ArrayAggregateImpl
     static NO_SANITIZE_UNDEFINED bool executeType(const ColumnPtr & mapped, const ColumnArray::Offsets & offsets, ColumnPtr & res_ptr)
     {
         using ResultType = ArrayAggregateResult<Element, aggregate_operation>;
-        using ColVecType = std::conditional_t<IsDecimalNumber<Element>, ColumnDecimal<Element>, ColumnVector<Element>>;
+        using ColVecType = ColumnVectorOrDecimal<Element>;
-        using ColVecResultType = std::conditional_t<IsDecimalNumber<ResultType>, ColumnDecimal<ResultType>, ColumnVector<ResultType>>;
+        using ColVecResultType = ColumnVectorOrDecimal<ResultType>;
 
         /// For average and product of array we return Float64 as result, but we want to keep precision
         /// so we convert to Float64 as last step, but intermediate value is represented as result of sum operation
@@ -160,7 +160,7 @@ struct ArrayAggregateImpl
             const auto & data = checkAndGetColumn<ColVecType>(&column_const->getDataColumn())->getData();
 
             typename ColVecResultType::MutablePtr res_column;
-            if constexpr (IsDecimalNumber<Element>)
+            if constexpr (is_decimal<Element>)
                 res_column = ColVecResultType::create(offsets.size(), data.getScale());
             else
                 res_column = ColVecResultType::create(offsets.size());
@@ -183,7 +183,7 @@ struct ArrayAggregateImpl
                 }
                 else if constexpr (aggregate_operation == AggregateOperation::average)
                 {
-                    if constexpr (IsDecimalNumber<Element>)
+                    if constexpr (is_decimal<Element>)
                     {
                         res[i] = DecimalUtils::convertTo<ResultType>(x, data.getScale());
                     }
@@ -197,7 +197,7 @@ struct ArrayAggregateImpl
                     size_t array_size = offsets[i] - pos;
                     AggregationType product = x;
 
-                    if constexpr (IsDecimalNumber<Element>)
+                    if constexpr (is_decimal<Element>)
                     {
                         using T = decltype(x.value);
                         T x_val = x.value;
@@ -235,7 +235,7 @@ struct ArrayAggregateImpl
         const auto & data = column->getData();
 
         typename ColVecResultType::MutablePtr res_column;
-        if constexpr (IsDecimalNumber<Element>)
+        if constexpr (is_decimal<Element>)
             res_column = ColVecResultType::create(offsets.size(), data.getScale());
         else
             res_column = ColVecResultType::create(offsets.size());
@@ -250,7 +250,7 @@ struct ArrayAggregateImpl
             /// Array is empty
             if (offsets[i] == pos)
             {
-                if constexpr (IsDecimalNumber<AggregationType>)
+                if constexpr (is_decimal<AggregationType>)
                     res[i] = aggregate_value.value;
                 else
                     res[i] = aggregate_value;
@@ -286,7 +286,7 @@ struct ArrayAggregateImpl
                 }
                 else if constexpr (aggregate_operation == AggregateOperation::product)
                 {
-                    if constexpr (IsDecimalNumber<Element>)
+                    if constexpr (is_decimal<Element>)
                     {
                         using AggregateValueDecimalUnderlyingValue = decltype(aggregate_value.value);
                         AggregateValueDecimalUnderlyingValue current_aggregate_value = aggregate_value.value;
@@ -306,7 +306,7 @@ struct ArrayAggregateImpl
 
             if constexpr (aggregate_operation == AggregateOperation::average)
             {
-                if constexpr (IsDecimalNumber<Element>)
+                if constexpr (is_decimal<Element>)
                 {
                     aggregate_value = aggregate_value / AggregationType(count);
                     res[i] = DecimalUtils::convertTo<ResultType>(aggregate_value, data.getScale());
@@ -316,7 +316,7 @@ struct ArrayAggregateImpl
                     res[i] = static_cast<ResultType>(aggregate_value) / count;
                 }
             }
-            else if constexpr (aggregate_operation == AggregateOperation::product && IsDecimalNumber<Element>)
+            else if constexpr (aggregate_operation == AggregateOperation::product && is_decimal<Element>)
             {
                 auto result_scale = data.getScale() * count;
 

src/Functions/array/arrayCompact.cpp

@@ -28,7 +28,7 @@ struct ArrayCompactImpl
     template <typename T>
     static bool executeType(const ColumnPtr & mapped, const ColumnArray & array, ColumnPtr & res_ptr)
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<T>, ColumnDecimal<T>, ColumnVector<T>>;
+        using ColVecType = ColumnVectorOrDecimal<T>;
 
         const ColVecType * src_values_column = checkAndGetColumn<ColVecType>(mapped.get());
 
@@ -39,7 +39,7 @@ struct ArrayCompactImpl
         const typename ColVecType::Container & src_values = src_values_column->getData();
 
         typename ColVecType::MutablePtr res_values_column;
-        if constexpr (IsDecimalNumber<T>)
+        if constexpr (is_decimal<T>)
             res_values_column = ColVecType::create(src_values.size(), src_values.getScale());
         else
             res_values_column = ColVecType::create(src_values.size());

src/Functions/array/arrayCumSum.cpp

@@ -83,8 +83,8 @@ struct ArrayCumSumImpl
     template <typename Element, typename Result>
     static bool executeType(const ColumnPtr & mapped, const ColumnArray & array, ColumnPtr & res_ptr)
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<Element>, ColumnDecimal<Element>, ColumnVector<Element>>;
+        using ColVecType = ColumnVectorOrDecimal<Element>;
-        using ColVecResult = std::conditional_t<IsDecimalNumber<Result>, ColumnDecimal<Result>, ColumnVector<Result>>;
+        using ColVecResult = ColumnVectorOrDecimal<Result>;
 
         const ColVecType * column = checkAndGetColumn<ColVecType>(&*mapped);
 
@@ -99,7 +99,7 @@ struct ArrayCumSumImpl
             const IColumn::Offsets & offsets = array.getOffsets();
 
             typename ColVecResult::MutablePtr res_nested;
-            if constexpr (IsDecimalNumber<Element>)
+            if constexpr (is_decimal<Element>)
             {
                 const typename ColVecType::Container & data =
                     checkAndGetColumn<ColVecType>(&column_const->getDataColumn())->getData();
@@ -119,7 +119,7 @@ struct ArrayCumSumImpl
         const IColumn::Offsets & offsets = array.getOffsets();
 
         typename ColVecResult::MutablePtr res_nested;
-        if constexpr (IsDecimalNumber<Element>)
+        if constexpr (is_decimal<Element>)
             res_nested = ColVecResult::create(0, data.getScale());
         else
             res_nested = ColVecResult::create();

src/Functions/array/arrayCumSumNonNegative.cpp

@@ -70,8 +70,8 @@ struct ArrayCumSumNonNegativeImpl
     template <typename Element, typename Result>
     static bool executeType(const ColumnPtr & mapped, const ColumnArray & array, ColumnPtr & res_ptr)
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<Element>, ColumnDecimal<Element>, ColumnVector<Element>>;
+        using ColVecType = ColumnVectorOrDecimal<Element>;
-        using ColVecResult = std::conditional_t<IsDecimalNumber<Result>, ColumnDecimal<Result>, ColumnVector<Result>>;
+        using ColVecResult = ColumnVectorOrDecimal<Result>;
 
         const ColVecType * column = checkAndGetColumn<ColVecType>(&*mapped);
 
@@ -82,7 +82,7 @@ struct ArrayCumSumNonNegativeImpl
         const typename ColVecType::Container & data = column->getData();
 
         typename ColVecResult::MutablePtr res_nested;
-        if constexpr (IsDecimalNumber<Element>)
+        if constexpr (is_decimal<Element>)
             res_nested = ColVecResult::create(0, data.getScale());
         else
             res_nested = ColVecResult::create();

src/Functions/array/arrayDifference.cpp

@@ -64,7 +64,7 @@ struct ArrayDifferenceImpl
             {
                 Element curr = src[pos];
 
-                if constexpr (IsDecimalNumber<Element>)
+                if constexpr (is_decimal<Element>)
                 {
                     using ResultNativeType = typename Result::NativeType;
 
@@ -92,8 +92,8 @@ struct ArrayDifferenceImpl
     template <typename Element, typename Result>
     static bool executeType(const ColumnPtr & mapped, const ColumnArray & array, ColumnPtr & res_ptr)
     {
-        using ColVecType = std::conditional_t<IsDecimalNumber<Element>, ColumnDecimal<Element>, ColumnVector<Element>>;
+        using ColVecType = ColumnVectorOrDecimal<Element>;
-        using ColVecResult = std::conditional_t<IsDecimalNumber<Result>, ColumnDecimal<Result>, ColumnVector<Result>>;
+        using ColVecResult = ColumnVectorOrDecimal<Result>;
 
         const ColVecType * column = checkAndGetColumn<ColVecType>(&*mapped);
 
@@ -104,7 +104,7 @@ struct ArrayDifferenceImpl
         const typename ColVecType::Container & data = column->getData();
 
         typename ColVecResult::MutablePtr res_nested;
-        if constexpr (IsDecimalNumber<Element>)
+        if constexpr (is_decimal<Element>)
             res_nested = ColVecResult::create(0, data.getScale());
         else
             res_nested = ColVecResult::create();

src/Functions/array/arrayElement.cpp

@@ -904,7 +904,7 @@ bool FunctionArrayElement::matchKeyToIndexString(
 template <typename FromType, typename ToType>
 static constexpr bool areConvertibleTypes =
     std::is_same_v<FromType, ToType>
-        || (is_integer_v<FromType> && is_integer_v<ToType>
+        || (is_integer<FromType> && is_integer<ToType>
             && std::is_convertible_v<FromType, ToType>);
 
 template <typename F>

src/Functions/array/mapOp.cpp

@@ -231,12 +231,10 @@ private:
                             key = col_fixed->getDataAt(offset + j).toString();
                         else if (const auto * col_str = checkAndGetColumn<ColumnString>(arg.key_column.get()))
                             key = col_str->getDataAt(offset + j).toString();
-                        else
+                        else // should not happen
-                            // should not happen
+                            throw Exception(ErrorCodes::LOGICAL_ERROR,
-                            throw Exception(
+                                "Expected String or FixedString, got {} in {}",
-                                "Expected String or FixedString, got " + std::string(getTypeName(arg.key_column->getDataType()))
+                                arg.key_column->getDataType(), getName());
-                                    + " in " + getName(),
-                                ErrorCodes::LOGICAL_ERROR);
                     }
                     else
                     {

src/Functions/bitWrapperFunc.cpp

@@ -25,7 +25,7 @@ struct BitWrapperFuncImpl
     {
         // Should be a logical error, but this function is callable from SQL.
         // Need to investigate this.
-        if constexpr (!is_integer_v<A>)
+        if constexpr (!is_integer<A>)
             throw DB::Exception("It's a bug! Only integer types are supported by __bitWrapperFunc.", ErrorCodes::BAD_ARGUMENTS);
         return a == 0 ? static_cast<ResultType>(0b10) : static_cast<ResultType >(0b1);
     }

src/Functions/castTypeToEither.h

@@ -5,6 +5,20 @@
 namespace DB
 {
 
+namespace detail
+{
+template <typename Typelist, size_t ...I>
+static bool castTypeToEither(const auto * type, auto && f, std::index_sequence<I...>)
+{
+    return (
+        (typeid_cast<const typename Typelist::template At<I> *>(type)
+            ? std::forward<decltype(f)>(f)(
+                *typeid_cast<const typename Typelist::template At<I> *>(type))
+            : false)
+        || ...);
+}
+}
+
 template <typename... Ts, typename T, typename F>
 static bool castTypeToEither(const T * type, F && f)
 {
@@ -12,4 +26,12 @@ static bool castTypeToEither(const T * type, F && f)
     return ((typeid_cast<const Ts *>(type) ? f(*typeid_cast<const Ts *>(type)) : false) || ...);
 }
 
+/// Use Common/TypeList as template argument
+template <class Typelist>
+static constexpr bool castTypeToEitherTL(const auto * type, auto && f)
+{
+    return detail::castTypeToEither<Typelist>(
+            type, std::forward<decltype(f)>(f),
+            std::make_index_sequence<Typelist::size>());
+}
 }

src/Functions/countDigits.cpp

@@ -61,7 +61,7 @@ public:
         {
             using Types = std::decay_t<decltype(types)>;
             using Type = typename Types::RightType;
-            using ColVecType = std::conditional_t<IsDecimalNumber<Type>, ColumnDecimal<Type>, ColumnVector<Type>>;
+            using ColVecType = ColumnVectorOrDecimal<Type>;
 
             if (const ColVecType * col_vec = checkAndGetColumn<ColVecType>(src_column.column.get()))
             {
@@ -84,7 +84,7 @@ private:
     template <typename T, typename ColVecType>
     static void execute(const ColVecType & col, ColumnUInt8 & result_column, size_t rows_count)
     {
-        using NativeT = typename NativeType<T>::Type;
+        using NativeT = NativeType<T>;
 
         const auto & src_data = col.getData();
         auto & dst_data = result_column.getData();
@@ -92,7 +92,7 @@ private:
 
         for (size_t i = 0; i < rows_count; ++i)
         {
-            if constexpr (IsDecimalNumber<T>)
+            if constexpr (is_decimal<T>)
                 dst_data[i] = digits<NativeT>(src_data[i].value);
             else
                 dst_data[i] = digits<NativeT>(src_data[i]);
@@ -102,7 +102,7 @@ private:
     template <typename T>
     static UInt32 digits(T value)
     {
-        static_assert(!IsDecimalNumber<T>);
+        static_assert(!is_decimal<T>);
         using DivT = std::conditional_t<is_signed_v<T>, Int32, UInt32>;
 
         UInt32 res = 0;

src/Functions/if.cpp

@@ -221,7 +221,7 @@ private:
     template <typename T0, typename T1>
     static UInt32 decimalScale(const ColumnsWithTypeAndName & arguments [[maybe_unused]])
     {
-        if constexpr (IsDecimalNumber<T0> && IsDecimalNumber<T1>)
+        if constexpr (is_decimal<T0> && is_decimal<T1>)
         {
             UInt32 left_scale = getDecimalScale(*arguments[1].type);
             UInt32 right_scale = getDecimalScale(*arguments[2].type);
@@ -416,8 +416,8 @@ private:
     ColumnPtr executeTyped(
         const ColumnUInt8 * cond_col, const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const
     {
-        using ColVecT0 = std::conditional_t<IsDecimalNumber<T0>, ColumnDecimal<T0>, ColumnVector<T0>>;
+        using ColVecT0 = ColumnVectorOrDecimal<T0>;
-        using ColVecT1 = std::conditional_t<IsDecimalNumber<T1>, ColumnDecimal<T1>, ColumnVector<T1>>;
+        using ColVecT1 = ColumnVectorOrDecimal<T1>;
 
         const IColumn * col_left_untyped = arguments[1].column.get();
 

src/Functions/isDecimalOverflow.cpp

@@ -128,10 +128,9 @@ private:
             dst_data[i] = outOfDigits<T>(src_data[i], precision);
     }
 
-    template <typename T>
+    template <is_decimal T>
     static bool outOfDigits(T dec, UInt32 precision)
     {
-        static_assert(IsDecimalNumber<T>);
         using NativeT = typename T::NativeType;
 
         if (precision > DecimalUtils::max_precision<T>)

src/Functions/negate.cpp

@@ -8,7 +8,7 @@ namespace DB
 template <typename A>
 struct NegateImpl
 {
-    using ResultType = std::conditional_t<IsDecimalNumber<A>, A, typename NumberTraits::ResultOfNegate<A>::Type>;
+    using ResultType = std::conditional_t<is_decimal<A>, A, typename NumberTraits::ResultOfNegate<A>::Type>;
     static constexpr const bool allow_fixed_string = false;
 
     static inline NO_SANITIZE_UNDEFINED ResultType apply(A a)

src/Functions/reinterpretAs.cpp

@@ -217,7 +217,7 @@ public:
                     using From = typename FromType::FieldType;
                     using To = typename ToType::FieldType;
 
-                    using FromColumnType = std::conditional_t<IsDecimalNumber<From>, ColumnDecimal<From>, ColumnVector<From>>;
+                    using FromColumnType = ColumnVectorOrDecimal<From>;
 
                     const auto * column_from = assert_cast<const FromColumnType*>(arguments[0].column.get());
 

src/Functions/sign.cpp

@@ -13,7 +13,7 @@ struct SignImpl
 
     static inline NO_SANITIZE_UNDEFINED ResultType apply(A a)
     {
-        if constexpr (IsDecimalNumber<A> || std::is_floating_point_v<A>)
+        if constexpr (is_decimal<A> || std::is_floating_point_v<A>)
             return a < A(0) ? -1 : a == A(0) ? 0 : 1;
         else if constexpr (is_signed_v<A>)
             return a < 0 ? -1 : a == 0 ? 0 : 1;

src/Functions/toStartOfInterval.cpp

@@ -261,10 +261,10 @@ public:
                         + ". This argument is optional and must be a constant string with timezone name",
                     ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
             if (first_argument_is_date && result_type_is_date)
-                throw Exception(
+                throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
-                    "The timezone argument of function " + getName() + " with interval type " + interval_type->getKind().toString()
+                    "The timezone argument of function {} with interval type {} is allowed only when the 1st argument "
-                        + " is allowed only when the 1st argument has the type DateTime",
+                    "has the type DateTime",
-                    ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+                        getName(), interval_type->getKind().toString());
         };
 
         if (arguments.size() == 2)

src/IO/Operators.h

@@ -41,16 +41,8 @@ struct QuoteManipReadBuffer          : std::reference_wrapper<ReadBuffer> { usin
 struct DoubleQuoteManipReadBuffer    : std::reference_wrapper<ReadBuffer> { using std::reference_wrapper<ReadBuffer>::reference_wrapper; };
 struct BinaryManipReadBuffer         : std::reference_wrapper<ReadBuffer> { using std::reference_wrapper<ReadBuffer>::reference_wrapper; };
 
-
+inline WriteBuffer & operator<<(WriteBuffer & buf, const auto & x) { writeText(x, buf); return buf; }
-template <typename T>     WriteBuffer & operator<< (WriteBuffer & buf, const T & x)        { writeText(x, buf);     return buf; }
+inline WriteBuffer & operator<<(WriteBuffer & buf, const pcg32_fast & x) { PcgSerializer::serializePcg32(x, buf); return buf; }
-/// If you do not use the manipulators, the string is displayed without an escape, as is.
-template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const String & x)   { writeString(x, buf);   return buf; }
-template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const std::string_view & x)   { writeString(StringRef(x), buf);   return buf; }
-template <> inline WriteBuffer & operator<< (WriteBuffer & buf, const StringRef & x) { writeString(x, buf); return buf; }
-template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const char & x)     { writeChar(x, buf);     return buf; }
-template <> inline        WriteBuffer & operator<< (WriteBuffer & buf, const pcg32_fast & x) { PcgSerializer::serializePcg32(x, buf); return buf; }
-
-inline WriteBuffer & operator<< (WriteBuffer & buf, const char * x)     { writeCString(x, buf); return buf; }
 
 inline EscapeManipWriteBuffer      operator<< (WriteBuffer & buf, EscapeManip)      { return buf; }
 inline QuoteManipWriteBuffer       operator<< (WriteBuffer & buf, QuoteManip)       { return buf; }
@@ -63,8 +55,8 @@ template <typename T> WriteBuffer & operator<< (DoubleQuoteManipWriteBuffer buf,
 template <typename T> WriteBuffer & operator<< (BinaryManipWriteBuffer buf,        const T & x) { writeBinary(x, buf.get());       return buf; }
 
 inline  WriteBuffer & operator<< (EscapeManipWriteBuffer buf, const String & x)   { writeEscapedString(x, buf); return buf; }
-inline  WriteBuffer & operator<< (EscapeManipWriteBuffer buf, const std::string_view & x) { writeEscapedString(x, buf); return buf; }
+inline  WriteBuffer & operator<< (EscapeManipWriteBuffer buf, std::string_view x) { writeEscapedString(x, buf); return buf; }
-inline  WriteBuffer & operator<< (EscapeManipWriteBuffer buf, const StringRef & x)        { writeEscapedString(x, buf); return buf; }
+inline  WriteBuffer & operator<< (EscapeManipWriteBuffer buf, StringRef x)        { writeEscapedString(x, buf); return buf; }
 inline  WriteBuffer & operator<< (EscapeManipWriteBuffer buf, const char * x)     { writeEscapedString(x, strlen(x), buf); return buf; }
 
 inline WriteBuffer & operator<< (QuoteManipWriteBuffer buf,       const char * x) { writeAnyQuotedString<'\''>(x, x + strlen(x), buf.get()); return buf; }