YT-21233: Issues and tidying up of rXXXXXX

commit_hash:19481c9fbb008aab4f4d676f1a3a242f6e90e90e

6 files changed, 39 insertions, 59 deletions

diff --git a/library/cpp/yt/error/error-inl.h b/library/cpp/yt/error/error-inl.h
index f9a7355d1a9..c1ba73fbcf0 100644
--- a/library/cpp/yt/error/error-inl.h
+++ b/library/cpp/yt/error/error-inl.h
@@ -154,17 +154,6 @@ TError TError::Wrap(TErrorCode code, TFormatString<TArgs...> format, TArgs&&...
 #undef IMPLEMENT_COPY_WRAP
 #undef IMPLEMENT_MOVE_WRAP
 
-template <CMergeableDictionary TDictionary>
-TError& TError::operator <<= (const TDictionary& attributes) &
-{
-    // This forces inclusion of error_attributes in the header file
-    // which is undesirable.
-    // One could (and probably should) implement type-erasure
-    // like AnyDictionaryRef to move this implementation in cpp file.
-    MutableAttributes()->MergeFrom(attributes);
-    return *this;
-}
-
 template <CErrorNestable TValue>
 TError&& TError::operator << (TValue&& rhs) &&
 {
diff --git a/library/cpp/yt/error/error.cpp b/library/cpp/yt/error/error.cpp
index bcc265ab2ed..59eea6ce8c6 100644
--- a/library/cpp/yt/error/error.cpp
+++ b/library/cpp/yt/error/error.cpp
@@ -435,7 +435,7 @@ bool TError::HasAttributes() const noexcept
 const TErrorAttributes& TError::Attributes() const
 {
     if (!Impl_) {
-        static TErrorAttributes empty = {};
+        static TErrorAttributes empty;
         return empty;
     }
     return Impl_->Attributes();
@@ -688,6 +688,12 @@ TError& TError::operator <<= (std::vector<TError>&& innerErrors) &
     return *this;
 }
 
+TError& TError::operator <<= (TAnyMergeableDictionaryRef attributes) &
+{
+    MutableAttributes()->MergeFrom(attributes);
+    return *this;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 bool operator == (const TError& lhs, const TError& rhs)
diff --git a/library/cpp/yt/error/error.h b/library/cpp/yt/error/error.h
index 6412ad029b8..eed1cfb75d5 100644
--- a/library/cpp/yt/error/error.h
+++ b/library/cpp/yt/error/error.h
@@ -202,8 +202,7 @@ public:
     TError& operator <<= (TError&& innerError) &;
     TError& operator <<= (const std::vector<TError>& innerErrors) &;
     TError& operator <<= (std::vector<TError>&& innerErrors) &;
-    template <CMergeableDictionary TDictionary>
-    TError& operator <<= (const TDictionary& attributes) &;
+    TError& operator <<= (TAnyMergeableDictionaryRef attributes) &;
 
     template <CErrorNestable TValue>
     TError&& operator << (TValue&& operand) &&;
diff --git a/library/cpp/yt/error/error_attributes-inl.h b/library/cpp/yt/error/error_attributes-inl.h
index 0a77d9afb0c..e6b39f531e9 100644
--- a/library/cpp/yt/error/error_attributes-inl.h
+++ b/library/cpp/yt/error/error_attributes-inl.h
@@ -78,23 +78,21 @@ typename TOptionalTraits<T>::TOptional TErrorAttributes::FindAndRemove(const TKe
 template <CMergeableDictionary TDictionary>
 void TErrorAttributes::MergeFrom(const TDictionary& dict)
 {
-    using TTraits = TMergeDictionariesTraits<TDictionary>;
-
-    for (const auto& [key, value] : TTraits::MakeIterableView(dict)) {
+    for (auto range = AsMergeableRange(dict); const auto& [key, value] : range) {
         SetValue(key, value);
     }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-template <>
-struct TMergeDictionariesTraits<TErrorAttributes>
+namespace NMergeableRangeImpl {
+
+inline TMergeableRange TagInvoke(TTagInvokeTag<AsMergeableRange>, const TErrorAttributes& attributes)
 {
-    static auto MakeIterableView(const TErrorAttributes& attributes)
-    {
-        return attributes.ListPairs();
-    }
-};
+    return attributes.ListPairs();
+}
+
+} // namespace NMergeableRangeImpl
 
 static_assert(CMergeableDictionary<TErrorAttributes>);
 
diff --git a/library/cpp/yt/error/mergeable_dictionary.h b/library/cpp/yt/error/mergeable_dictionary.h
index 361694d8416..cf866f3da7c 100644
--- a/library/cpp/yt/error/mergeable_dictionary.h
+++ b/library/cpp/yt/error/mergeable_dictionary.h
@@ -1,58 +1,45 @@
 #pragma once
 
-#include "public.h"
 #include "error_attribute.h"
 
+#include <library/cpp/yt/memory/type_erasure.h>
+
+#include <library/cpp/yt/misc/tag_invoke_cpo.h>
+
 #include <ranges>
 
 namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-// Can be specialized to make your dictionary satisfy CMergeableDictionary.
-template <class TDictionary>
-struct TMergeDictionariesTraits
-{
-    static auto MakeIterableView(const TDictionary& dict)
-        requires false;
-};
+namespace NMergeableRangeImpl {
+
+struct TFn
+    : public TTagInvokeCpoBase<TFn>
+{ };
 
 ////////////////////////////////////////////////////////////////////////////////
 
-namespace NDetail {
+using TMergeableRange = std::vector<std::pair<TErrorAttribute::TKey, TErrorAttribute::TValue>>;
 
-template <class T>
-struct TMergeableDictionaryImpl
-{
-    // TL;DR: MakeIterableView returns something like std::span<std::pair<TKey, TValue>>.
-    using TView = std::invoke_result_t<decltype(&TMergeDictionariesTraits<T>::MakeIterableView), const T&>;
-    using TIterator = std::ranges::iterator_t<TView>;
-    using TValue = typename std::iterator_traits<TIterator>::value_type;
+} // namespace NMergeableRangeImpl
 
-    static constexpr bool ValidSize = requires {
-        { std::tuple_size<TValue>::value } -> std::same_as<const size_t&>;
-    } && (std::tuple_size<TValue>::value == 2);
+////////////////////////////////////////////////////////////////////////////////
 
-    static constexpr bool CorrectTupleElements = requires {
-        typename std::tuple_element<0, TValue>::type;
-        std::same_as<typename std::tuple_element<0, TValue>::type, TErrorAttribute::TKey>;
+// Can be customized to make your dictionary satisfy CMergeableDictionary.
+inline constexpr NMergeableRangeImpl::TFn AsMergeableRange = {};
 
-        typename std::tuple_element<1, TValue>::type;
-        std::same_as<typename std::tuple_element<1, TValue>::type, TErrorAttribute::TValue>;
-    };
-};
+////////////////////////////////////////////////////////////////////////////////
 
-} // namespace NDetail
+template <class T>
+concept CMergeableDictionary = CTagInvocableS<
+    TTagInvokeTag<AsMergeableRange>,
+    NMergeableRangeImpl::TMergeableRange(const T&)>;
 
 ////////////////////////////////////////////////////////////////////////////////
 
-template <class T>
-concept CMergeableDictionary =
-    requires (const T& dict) {
-        TMergeDictionariesTraits<T>::MakeIterableView(dict);
-    } &&
-    NDetail::TMergeableDictionaryImpl<T>::ValidSize &&
-    NDetail::TMergeableDictionaryImpl<T>::CorrectTupleElements;
+using TAnyMergeableDictionaryRef = TAnyRef<
+    TOverload<AsMergeableRange, NMergeableRangeImpl::TMergeableRange(const TErasedThis&)>>;
 
 ////////////////////////////////////////////////////////////////////////////////
 
diff --git a/library/cpp/yt/string/string.cpp b/library/cpp/yt/string/string.cpp
index 3cf5651e230..b9c32361343 100644
--- a/library/cpp/yt/string/string.cpp
+++ b/library/cpp/yt/string/string.cpp
@@ -362,7 +362,8 @@ TStringBuf FormatBool(bool value)
 void TruncateStringInplace(TString* string, int lengthLimit, TStringBuf truncatedSuffix)
 {
     if (std::ssize(*string) > lengthLimit) {
-        *string = Format("%v%v", string->substr(0, lengthLimit), truncatedSuffix);
+        string->resize(lengthLimit);
+        string->append(truncatedSuffix);
     }
 }