YT-21868: Reorganize files to prevent unclear missing include errors

Moving files around so that include of either `string_builder.h` or `format.h` would result in being able to use both `Format` and `TStringBuilder`
8a2abbea2ae7027c1cd3a243ab3de55bdd5d3d27

10 files changed, 433 insertions, 344 deletions

diff --git a/library/cpp/yt/string/enum-inl.h b/library/cpp/yt/string/enum-inl.h
index d9f8239cbd..41f7197d15 100644
--- a/library/cpp/yt/string/enum-inl.h
+++ b/library/cpp/yt/string/enum-inl.h
@@ -9,6 +9,7 @@
 #include <library/cpp/yt/exception/exception.h>
 
 #include <util/string/printf.h>
+#include <util/string/strip.h>
 
 namespace NYT {
 
diff --git a/library/cpp/yt/string/enum.h b/library/cpp/yt/string/enum.h
index b4b8d59171..792e09402d 100644
--- a/library/cpp/yt/string/enum.h
+++ b/library/cpp/yt/string/enum.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "string.h"
+#include "format_arg.h"
 
 #include <library/cpp/yt/misc/enum.h>
 
diff --git a/library/cpp/yt/string/format-inl.h b/library/cpp/yt/string/format-inl.h
index 1ff2d816c5..4eaa70bef2 100644
--- a/library/cpp/yt/string/format-inl.h
+++ b/library/cpp/yt/string/format-inl.h
@@ -4,6 +4,7 @@
 #include "format.h"
 #endif
 
+#include "guid.h"
 #include "enum.h"
 #include "string.h"
 
@@ -33,6 +34,155 @@ namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
+inline char* TStringBuilderBase::Preallocate(size_t size)
+{
+    Reserve(size + GetLength());
+    return Current_;
+}
+
+inline void TStringBuilderBase::Reserve(size_t size)
+{
+    if (Y_UNLIKELY(End_ - Begin_ < static_cast<ssize_t>(size))) {
+        size_t length = GetLength();
+        auto newLength = std::max(size, MinBufferLength);
+        DoReserve(newLength);
+        Current_ = Begin_ + length;
+    }
+}
+
+inline size_t TStringBuilderBase::GetLength() const
+{
+    return Current_ ? Current_ - Begin_ : 0;
+}
+
+inline TStringBuf TStringBuilderBase::GetBuffer() const
+{
+    return TStringBuf(Begin_, Current_);
+}
+
+inline void TStringBuilderBase::Advance(size_t size)
+{
+    Current_ += size;
+    YT_ASSERT(Current_ <= End_);
+}
+
+inline void TStringBuilderBase::AppendChar(char ch)
+{
+    *Preallocate(1) = ch;
+    Advance(1);
+}
+
+inline void TStringBuilderBase::AppendChar(char ch, int n)
+{
+    YT_ASSERT(n >= 0);
+    if (Y_LIKELY(0 != n)) {
+        char* dst = Preallocate(n);
+        ::memset(dst, ch, n);
+        Advance(n);
+    }
+}
+
+inline void TStringBuilderBase::AppendString(TStringBuf str)
+{
+    if (Y_LIKELY(str)) {
+        char* dst = Preallocate(str.length());
+        ::memcpy(dst, str.begin(), str.length());
+        Advance(str.length());
+    }
+}
+
+inline void TStringBuilderBase::AppendString(const char* str)
+{
+    AppendString(TStringBuf(str));
+}
+
+inline void TStringBuilderBase::Reset()
+{
+    Begin_ = Current_ = End_ = nullptr;
+    DoReset();
+}
+
+template <class... TArgs>
+void TStringBuilderBase::AppendFormat(TStringBuf format, TArgs&& ... args)
+{
+    Format(this, TRuntimeFormat{format}, std::forward<TArgs>(args)...);
+}
+
+template <size_t Length, class... TArgs>
+void TStringBuilderBase::AppendFormat(const char (&format)[Length], TArgs&& ... args)
+{
+    Format(this, TRuntimeFormat{format}, std::forward<TArgs>(args)...);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+inline TString TStringBuilder::Flush()
+{
+    Buffer_.resize(GetLength());
+    auto result = std::move(Buffer_);
+    Reset();
+    return result;
+}
+
+inline void TStringBuilder::DoReset()
+{
+    Buffer_ = {};
+}
+
+inline void TStringBuilder::DoReserve(size_t newLength)
+{
+    Buffer_.ReserveAndResize(newLength);
+    auto capacity = Buffer_.capacity();
+    Buffer_.ReserveAndResize(capacity);
+    Begin_ = &*Buffer_.begin();
+    End_ = Begin_ + capacity;
+}
+
+inline void FormatValue(TStringBuilderBase* builder, const TStringBuilder& value, TStringBuf /*spec*/)
+{
+    builder->AppendString(value.GetBuffer());
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T>
+TString ToStringViaBuilder(const T& value, TStringBuf spec)
+{
+    TStringBuilder builder;
+    FormatValue(&builder, value, spec);
+    return builder.Flush();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+// Compatibility for users of NYT::ToString(nyt_type).
+template <CFormattable T>
+TString ToString(const T& t)
+{
+    return ToStringViaBuilder(t);
+}
+
+// Sometime we want to implement
+// FormatValue using util's ToString
+// However, if we inside the FormatValue
+// we cannot just call the ToString since
+// in this scope T is already CFormattable
+// and ToString will call the very
+// FormatValue we are implementing,
+// causing an infinite recursion loop.
+// This method is basically a call to
+// util's ToString default implementation.
+template <class T>
+TString ToStringIgnoringFormatValue(const T& t)
+{
+    TString s;
+    ::TStringOutput o(s);
+    o << t;
+    return s;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
 // Helper functions for formatting.
 namespace NDetail {
 
@@ -887,3 +1037,30 @@ TString FormatVector(
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT
+
+#include <util/string/cast.h>
+
+// util/string/cast.h extension for yt and std types only
+// TODO(arkady-e1ppa): Abolish ::ToString in
+// favour of either NYT::ToString or
+// automatic formatting wherever it is needed.
+namespace NPrivate {
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T>
+    requires (
+        (NYT::NDetail::IsNYTName<T>() ||
+        NYT::NDetail::IsStdName<T>()) &&
+        NYT::CFormattable<T>)
+struct TToString<T, false>
+{
+    static TString Cvt(const T& t)
+    {
+        return NYT::ToStringViaBuilder(t);
+    }
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NPrivate
diff --git a/library/cpp/yt/string/format.h b/library/cpp/yt/string/format.h
index 9e12d286b7..a6ab1f76f4 100644
--- a/library/cpp/yt/string/format.h
+++ b/library/cpp/yt/string/format.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "string_builder.h"
+#include "format_string.h"
+
+#include <util/generic/string.h>
 
 namespace NYT {
 
@@ -55,12 +57,79 @@ namespace NYT {
  */
 
 template <class... TArgs>
-void Format(TStringBuilderBase* builder, TFormatString<TArgs...> format, TArgs&&... args);
-template <class... TArgs>
 TString Format(TFormatString<TArgs...> format, TArgs&&... args);
 
 ////////////////////////////////////////////////////////////////////////////////
 
+// StringBuilder(Base) definition.
+
+//! A simple helper for constructing strings by a sequence of appends.
+class TStringBuilderBase
+{
+public:
+    virtual ~TStringBuilderBase() = default;
+
+    char* Preallocate(size_t size);
+
+    void Reserve(size_t size);
+
+    size_t GetLength() const;
+
+    TStringBuf GetBuffer() const;
+
+    void Advance(size_t size);
+
+    void AppendChar(char ch);
+    void AppendChar(char ch, int n);
+
+    void AppendString(TStringBuf str);
+    void AppendString(const char* str);
+
+    template <size_t Length, class... TArgs>
+    void AppendFormat(const char (&format)[Length], TArgs&&... args);
+    template <class... TArgs>
+    void AppendFormat(TStringBuf format, TArgs&&... args);
+
+    void Reset();
+
+protected:
+    char* Begin_ = nullptr;
+    char* Current_ = nullptr;
+    char* End_ = nullptr;
+
+    virtual void DoReset() = 0;
+    virtual void DoReserve(size_t newLength) = 0;
+
+    static constexpr size_t MinBufferLength = 128;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TStringBuilder
+    : public TStringBuilderBase
+{
+public:
+    TString Flush();
+
+protected:
+    TString Buffer_;
+
+    void DoReset() override;
+    void DoReserve(size_t size) override;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class... TArgs>
+void Format(TStringBuilderBase* builder, TFormatString<TArgs...> format, TArgs&&... args);
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T>
+TString ToStringViaBuilder(const T& value, TStringBuf spec = TStringBuf("v"));
+
+////////////////////////////////////////////////////////////////////////////////
+
 template <class TRange, class TFormatter>
 struct TFormattableView
 {
diff --git a/library/cpp/yt/string/guid.cpp b/library/cpp/yt/string/guid.cpp
index 2a781d032d..b18ac3e128 100644
--- a/library/cpp/yt/string/guid.cpp
+++ b/library/cpp/yt/string/guid.cpp
@@ -1,10 +1,12 @@
 #include "guid.h"
 
+#include "format.h"
+
 namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-void FormatValue(TStringBuilderBase* builder, TGuid value, TStringBuf /*format*/)
+void FormatValue(TStringBuilderBase* builder, TGuid value, TStringBuf /*spec*/)
 {
     char* begin = builder->Preallocate(MaxGuidStringSize);
     char* end = WriteGuidToBuffer(begin, value);
diff --git a/library/cpp/yt/string/guid.h b/library/cpp/yt/string/guid.h
index de16993486..fd3943bafd 100644
--- a/library/cpp/yt/string/guid.h
+++ b/library/cpp/yt/string/guid.h
@@ -1,12 +1,14 @@
-#include <library/cpp/yt/misc/guid.h>
+#pragma once
+
+#include "format_arg.h"
 
-#include "format.h"
+#include <library/cpp/yt/misc/guid.h>
 
 namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-void FormatValue(TStringBuilderBase* builder, TGuid value, TStringBuf /*format*/);
+void FormatValue(TStringBuilderBase* builder, TGuid value, TStringBuf /*spec*/);
 
 ////////////////////////////////////////////////////////////////////////////////
 
diff --git a/library/cpp/yt/string/string-inl.h b/library/cpp/yt/string/string-inl.h
new file mode 100644
index 0000000000..baf789b4f1
--- /dev/null
+++ b/library/cpp/yt/string/string-inl.h
@@ -0,0 +1,158 @@
+#ifndef STRING_INL_H_
+#error "Direct inclusion of this file is not allowed, include string.h"
+// For the sake of sane code completion.
+#include "string.h"
+#endif
+
+#include "format.h"
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+//! Joins a range of items into a string intermixing them with the delimiter.
+/*!
+ *  \param builder String builder where the output goes.
+ *  \param begin Iterator pointing to the first item (inclusive).
+ *  \param end Iterator pointing to the last item (not inclusive).
+ *  \param formatter Formatter to apply to the items.
+ *  \param delimiter A delimiter to be inserted between items: ", " by default.
+ *  \return The resulting combined string.
+ */
+template <class TIterator, class TFormatter>
+void JoinToString(
+    TStringBuilderBase* builder,
+    const TIterator& begin,
+    const TIterator& end,
+    const TFormatter& formatter,
+    TStringBuf delimiter)
+{
+    for (auto current = begin; current != end; ++current) {
+        if (current != begin) {
+            builder->AppendString(delimiter);
+        }
+        formatter(builder, *current);
+    }
+}
+
+template <class TIterator, class TFormatter>
+TString JoinToString(
+    const TIterator& begin,
+    const TIterator& end,
+    const TFormatter& formatter,
+    TStringBuf delimiter)
+{
+    TStringBuilder builder;
+    JoinToString(&builder, begin, end, formatter, delimiter);
+    return builder.Flush();
+}
+
+//! A handy shortcut with default formatter.
+template <class TIterator>
+TString JoinToString(
+    const TIterator& begin,
+    const TIterator& end,
+    TStringBuf delimiter)
+{
+    return JoinToString(begin, end, TDefaultFormatter(), delimiter);
+}
+
+//! Joins a collection of given items into a string intermixing them with the delimiter.
+/*!
+ *  \param collection A collection containing the items to be joined.
+ *  \param formatter Formatter to apply to the items.
+ *  \param delimiter A delimiter to be inserted between items; ", " by default.
+ */
+template <class TCollection, class TFormatter>
+TString JoinToString(
+    const TCollection& collection,
+    const TFormatter& formatter,
+    TStringBuf delimiter)
+{
+    using std::begin;
+    using std::end;
+    return JoinToString(begin(collection), end(collection), formatter, delimiter);
+}
+
+//! A handy shortcut with the default formatter.
+template <class TCollection>
+TString JoinToString(
+    const TCollection& collection,
+    TStringBuf delimiter)
+{
+    return JoinToString(collection, TDefaultFormatter(), delimiter);
+}
+
+//! Concatenates a bunch of TStringBuf-like instances into TString.
+template <class... Ts>
+TString ConcatToString(Ts... args)
+{
+    size_t length = 0;
+    ((length += args.length()), ...);
+
+    TString result;
+    result.reserve(length);
+    (result.append(args), ...);
+
+    return result;
+}
+
+//! Converts a range of items into strings.
+template <class TIter, class TFormatter>
+std::vector<TString> ConvertToStrings(
+    const TIter& begin,
+    const TIter& end,
+    const TFormatter& formatter,
+    size_t maxSize)
+{
+    std::vector<TString> result;
+    for (auto it = begin; it != end; ++it) {
+        TStringBuilder builder;
+        formatter(&builder, *it);
+        result.push_back(builder.Flush());
+        if (result.size() == maxSize) {
+            break;
+        }
+    }
+    return result;
+}
+
+//! A handy shortcut with the default formatter.
+template <class TIter>
+std::vector<TString> ConvertToStrings(
+    const TIter& begin,
+    const TIter& end,
+    size_t maxSize)
+{
+    return ConvertToStrings(begin, end, TDefaultFormatter(), maxSize);
+}
+
+//! Converts a given collection of items into strings.
+/*!
+ *  \param collection A collection containing the items to be converted.
+ *  \param formatter Formatter to apply to the items.
+ *  \param maxSize Size limit for the resulting vector.
+ */
+template <class TCollection, class TFormatter>
+std::vector<TString> ConvertToStrings(
+    const TCollection& collection,
+    const TFormatter& formatter,
+    size_t maxSize)
+{
+    using std::begin;
+    using std::end;
+    return ConvertToStrings(begin(collection), end(collection), formatter, maxSize);
+}
+
+//! A handy shortcut with default formatter.
+template <class TCollection>
+std::vector<TString> ConvertToStrings(
+    const TCollection& collection,
+    size_t maxSize)
+{
+    return ConvertToStrings(collection, TDefaultFormatter(), maxSize);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
diff --git a/library/cpp/yt/string/string.h b/library/cpp/yt/string/string.h
index a131b40a2a..8257c1a5ea 100644
--- a/library/cpp/yt/string/string.h
+++ b/library/cpp/yt/string/string.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "string_builder.h"
+#include "format_arg.h"
 
 #include <util/datetime/base.h>
 
@@ -52,37 +52,21 @@ void JoinToString(
     const TIterator& begin,
     const TIterator& end,
     const TFormatter& formatter,
-    TStringBuf delimiter = DefaultJoinToStringDelimiter)
-{
-    for (auto current = begin; current != end; ++current) {
-        if (current != begin) {
-            builder->AppendString(delimiter);
-        }
-        formatter(builder, *current);
-    }
-}
+    TStringBuf delimiter = DefaultJoinToStringDelimiter);
 
 template <class TIterator, class TFormatter>
 TString JoinToString(
     const TIterator& begin,
     const TIterator& end,
     const TFormatter& formatter,
-    TStringBuf delimiter = DefaultJoinToStringDelimiter)
-{
-    TStringBuilder builder;
-    JoinToString(&builder, begin, end, formatter, delimiter);
-    return builder.Flush();
-}
+    TStringBuf delimiter = DefaultJoinToStringDelimiter);
 
 //! A handy shortcut with default formatter.
 template <class TIterator>
 TString JoinToString(
     const TIterator& begin,
     const TIterator& end,
-    TStringBuf delimiter = DefaultJoinToStringDelimiter)
-{
-    return JoinToString(begin, end, TDefaultFormatter(), delimiter);
-}
+    TStringBuf delimiter = DefaultJoinToStringDelimiter);
 
 //! Joins a collection of given items into a string intermixing them with the delimiter.
 /*!
@@ -94,35 +78,17 @@ template <class TCollection, class TFormatter>
 TString JoinToString(
     const TCollection& collection,
     const TFormatter& formatter,
-    TStringBuf delimiter = DefaultJoinToStringDelimiter)
-{
-    using std::begin;
-    using std::end;
-    return JoinToString(begin(collection), end(collection), formatter, delimiter);
-}
+    TStringBuf delimiter = DefaultJoinToStringDelimiter);
 
 //! A handy shortcut with the default formatter.
 template <class TCollection>
 TString JoinToString(
     const TCollection& collection,
-    TStringBuf delimiter = DefaultJoinToStringDelimiter)
-{
-    return JoinToString(collection, TDefaultFormatter(), delimiter);
-}
+    TStringBuf delimiter = DefaultJoinToStringDelimiter);
 
 //! Concatenates a bunch of TStringBuf-like instances into TString.
 template <class... Ts>
-TString ConcatToString(Ts... args)
-{
-    size_t length = 0;
-    ((length += args.length()), ...);
-
-    TString result;
-    result.reserve(length);
-    (result.append(args), ...);
-
-    return result;
-}
+TString ConcatToString(Ts... args);
 
 //! Converts a range of items into strings.
 template <class TIter, class TFormatter>
@@ -130,29 +96,14 @@ std::vector<TString> ConvertToStrings(
     const TIter& begin,
     const TIter& end,
     const TFormatter& formatter,
-    size_t maxSize = std::numeric_limits<size_t>::max())
-{
-    std::vector<TString> result;
-    for (auto it = begin; it != end; ++it) {
-        TStringBuilder builder;
-        formatter(&builder, *it);
-        result.push_back(builder.Flush());
-        if (result.size() == maxSize) {
-            break;
-        }
-    }
-    return result;
-}
+    size_t maxSize = std::numeric_limits<size_t>::max());
 
 //! A handy shortcut with the default formatter.
 template <class TIter>
 std::vector<TString> ConvertToStrings(
     const TIter& begin,
     const TIter& end,
-    size_t maxSize = std::numeric_limits<size_t>::max())
-{
-    return ConvertToStrings(begin, end, TDefaultFormatter(), maxSize);
-}
+    size_t maxSize = std::numeric_limits<size_t>::max());
 
 //! Converts a given collection of items into strings.
 /*!
@@ -164,21 +115,13 @@ template <class TCollection, class TFormatter>
 std::vector<TString> ConvertToStrings(
     const TCollection& collection,
     const TFormatter& formatter,
-    size_t maxSize = std::numeric_limits<size_t>::max())
-{
-    using std::begin;
-    using std::end;
-    return ConvertToStrings(begin(collection), end(collection), formatter, maxSize);
-}
+    size_t maxSize = std::numeric_limits<size_t>::max());
 
 //! A handy shortcut with default formatter.
 template <class TCollection>
 std::vector<TString> ConvertToStrings(
     const TCollection& collection,
-    size_t maxSize = std::numeric_limits<size_t>::max())
-{
-    return ConvertToStrings(collection, TDefaultFormatter(), maxSize);
-}
+    size_t maxSize = std::numeric_limits<size_t>::max());
 
 ////////////////////////////////////////////////////////////////////////////////
 
@@ -222,3 +165,7 @@ TStringBuf FormatBool(bool value);
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT
+
+#define STRING_INL_H_
+#include "string-inl.h"
+#undef STRING_INL_H_
diff --git a/library/cpp/yt/string/string_builder-inl.h b/library/cpp/yt/string/string_builder-inl.h
deleted file mode 100644
index 24f1e33880..0000000000
--- a/library/cpp/yt/string/string_builder-inl.h
+++ /dev/null
@@ -1,191 +0,0 @@
-#ifndef STRING_BUILDER_INL_H_
-#error "Direct inclusion of this file is not allowed, include string.h"
-// For the sake of sane code completion.
-#include "string_builder.h"
-#endif
-
-#include <library/cpp/yt/assert/assert.h>
-
-#include <util/stream/str.h>
-
-namespace NYT {
-
-////////////////////////////////////////////////////////////////////////////////
-
-inline char* TStringBuilderBase::Preallocate(size_t size)
-{
-    Reserve(size + GetLength());
-    return Current_;
-}
-
-inline void TStringBuilderBase::Reserve(size_t size)
-{
-    if (Y_UNLIKELY(End_ - Begin_ < static_cast<ssize_t>(size))) {
-        size_t length = GetLength();
-        auto newLength = std::max(size, MinBufferLength);
-        DoReserve(newLength);
-        Current_ = Begin_ + length;
-    }
-}
-
-inline size_t TStringBuilderBase::GetLength() const
-{
-    return Current_ ? Current_ - Begin_ : 0;
-}
-
-inline TStringBuf TStringBuilderBase::GetBuffer() const
-{
-    return TStringBuf(Begin_, Current_);
-}
-
-inline void TStringBuilderBase::Advance(size_t size)
-{
-    Current_ += size;
-    YT_ASSERT(Current_ <= End_);
-}
-
-inline void TStringBuilderBase::AppendChar(char ch)
-{
-    *Preallocate(1) = ch;
-    Advance(1);
-}
-
-inline void TStringBuilderBase::AppendChar(char ch, int n)
-{
-    YT_ASSERT(n >= 0);
-    if (Y_LIKELY(0 != n)) {
-        char* dst = Preallocate(n);
-        ::memset(dst, ch, n);
-        Advance(n);
-    }
-}
-
-inline void TStringBuilderBase::AppendString(TStringBuf str)
-{
-    if (Y_LIKELY(str)) {
-        char* dst = Preallocate(str.length());
-        ::memcpy(dst, str.begin(), str.length());
-        Advance(str.length());
-    }
-}
-
-inline void TStringBuilderBase::AppendString(const char* str)
-{
-    AppendString(TStringBuf(str));
-}
-
-inline void TStringBuilderBase::Reset()
-{
-    Begin_ = Current_ = End_ = nullptr;
-    DoReset();
-}
-
-template <class... TArgs>
-void TStringBuilderBase::AppendFormat(TStringBuf format, TArgs&& ... args)
-{
-    Format(this, TRuntimeFormat{format}, std::forward<TArgs>(args)...);
-}
-
-template <size_t Length, class... TArgs>
-void TStringBuilderBase::AppendFormat(const char (&format)[Length], TArgs&& ... args)
-{
-    Format(this, TRuntimeFormat{format}, std::forward<TArgs>(args)...);
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
-inline TString TStringBuilder::Flush()
-{
-    Buffer_.resize(GetLength());
-    auto result = std::move(Buffer_);
-    Reset();
-    return result;
-}
-
-inline void TStringBuilder::DoReset()
-{
-    Buffer_ = {};
-}
-
-inline void TStringBuilder::DoReserve(size_t newLength)
-{
-    Buffer_.ReserveAndResize(newLength);
-    auto capacity = Buffer_.capacity();
-    Buffer_.ReserveAndResize(capacity);
-    Begin_ = &*Buffer_.begin();
-    End_ = Begin_ + capacity;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
-inline void FormatValue(TStringBuilderBase* builder, const TStringBuilder& value, TStringBuf /*spec*/)
-{
-    builder->AppendString(value.GetBuffer());
-}
-
-template <class T>
-TString ToStringViaBuilder(const T& value, TStringBuf spec)
-{
-    TStringBuilder builder;
-    FormatValue(&builder, value, spec);
-    return builder.Flush();
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
-// Compatibility for users of NYT::ToString(nyt_type).
-template <CFormattable T>
-TString ToString(const T& t)
-{
-    return ToStringViaBuilder(t);
-}
-
-// Sometime we want to implement
-// FormatValue using util's ToString
-// However, if we inside the FormatValue
-// we cannot just call the ToString since
-// in this scope T is already CFormattable
-// and ToString will call the very
-// FormatValue we are implementing,
-// causing an infinite recursion loop.
-// This method is basically a call to
-// util's ToString default implementation.
-template <class T>
-TString ToStringIgnoringFormatValue(const T& t)
-{
-    TString s;
-    ::TStringOutput o(s);
-    o << t;
-    return s;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-
-} // namespace NYT
-
-#include <util/string/cast.h>
-
-// util/string/cast.h extension for yt and std types only
-// TODO(arkady-e1ppa): Abolish ::ToString in
-// favour of either NYT::ToString or
-// automatic formatting wherever it is needed.
-namespace NPrivate {
-
-////////////////////////////////////////////////////////////////////////////////
-
-template <class T>
-    requires (
-        (NYT::NDetail::IsNYTName<T>() ||
-        NYT::NDetail::IsStdName<T>()) &&
-        NYT::CFormattable<T>)
-struct TToString<T, false>
-{
-    static TString Cvt(const T& t)
-    {
-        return NYT::ToStringViaBuilder(t);
-    }
-};
-
-////////////////////////////////////////////////////////////////////////////////
-
-} // namespace NPrivate
diff --git a/library/cpp/yt/string/string_builder.h b/library/cpp/yt/string/string_builder.h
index 4cba45bc72..de1c1abb1e 100644
--- a/library/cpp/yt/string/string_builder.h
+++ b/library/cpp/yt/string/string_builder.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "format_string.h"
+#include "format.h"
 
 #include <util/generic/string.h>
 
@@ -8,78 +8,6 @@ namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-// Forward declarations.
-class TStringBuilderBase;
-class TStringBuilder;
-class TDelimitedStringBuilderWrapper;
-
-template <class... TArgs>
-void Format(TStringBuilderBase* builder, TFormatString<TArgs...> fmt, TArgs&&... args);
-
-////////////////////////////////////////////////////////////////////////////////
-
-//! A simple helper for constructing strings by a sequence of appends.
-class TStringBuilderBase
-{
-public:
-    virtual ~TStringBuilderBase() = default;
-
-    char* Preallocate(size_t size);
-
-    void Reserve(size_t size);
-
-    size_t GetLength() const;
-
-    TStringBuf GetBuffer() const;
-
-    void Advance(size_t size);
-
-    void AppendChar(char ch);
-    void AppendChar(char ch, int n);
-
-    void AppendString(TStringBuf str);
-    void AppendString(const char* str);
-
-    template <size_t Length, class... TArgs>
-    void AppendFormat(const char (&format)[Length], TArgs&&... args);
-    template <class... TArgs>
-    void AppendFormat(TStringBuf format, TArgs&&... args);
-
-    void Reset();
-
-protected:
-    char* Begin_ = nullptr;
-    char* Current_ = nullptr;
-    char* End_ = nullptr;
-
-    virtual void DoReset() = 0;
-    virtual void DoReserve(size_t newLength) = 0;
-
-    static constexpr size_t MinBufferLength = 128;
-};
-
-////////////////////////////////////////////////////////////////////////////////
-
-class TStringBuilder
-    : public TStringBuilderBase
-{
-public:
-    TString Flush();
-
-protected:
-    TString Buffer_;
-
-    void DoReset() override;
-    void DoReserve(size_t size) override;
-};
-
-////////////////////////////////////////////////////////////////////////////////
-
-template <class T>
-TString ToStringViaBuilder(const T& value, TStringBuf spec = TStringBuf("v"));
-
-////////////////////////////////////////////////////////////////////////////////
-
 //! Appends a certain delimiter starting from the second call.
 class TDelimitedStringBuilderWrapper
     : private TNonCopyable
@@ -111,7 +39,3 @@ private:
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT
-
-#define STRING_BUILDER_INL_H_
-#include "string_builder-inl.h"
-#undef STRING_BUILDER_INL_H_