YT-22593: TString -> std::string in unittests

commit_hash:e71661ee774f94e598456363e42562c658cce049

33 files changed, 161 insertions, 156 deletions

diff --git a/library/cpp/yt/yson_string/convert.cpp b/library/cpp/yt/yson_string/convert.cpp
index ca344282901..51094255ae7 100644
--- a/library/cpp/yt/yson_string/convert.cpp
+++ b/library/cpp/yt/yson_string/convert.cpp
@@ -315,6 +315,17 @@ TString ConvertFromYsonString<TString>(const TYsonStringBuf& str)
 }
 
 template <>
+std::string ConvertFromYsonString<std::string>(const TYsonStringBuf& str)
+{
+    try {
+        // TODO(sabdenovch): Avoid copying.
+        return ParseStringFromYsonString(str);
+    } catch (const std::exception& ex) {
+        throw TYsonLiteralParseException(ex, "Error parsing \"string\" value from YSON");
+    }
+}
+
+template <>
 float ConvertFromYsonString<float>(const TYsonStringBuf& str)
 {
     try {
diff --git a/yt/cpp/mapreduce/interface/ut/job_counters_ut.cpp b/yt/cpp/mapreduce/interface/ut/job_counters_ut.cpp
index 1c887b37e17..5d1ab8e5662 100644
--- a/yt/cpp/mapreduce/interface/ut/job_counters_ut.cpp
+++ b/yt/cpp/mapreduce/interface/ut/job_counters_ut.cpp
@@ -9,7 +9,7 @@ using namespace NYT;
 
 TEST(TJobCountersTest, Full)
 {
-    const TString input = R"""(
+    const TStringBuf input = R"""(
         {
             "completed" = {
                 "total" = 6;
diff --git a/yt/cpp/mapreduce/interface/ut/job_statistics_ut.cpp b/yt/cpp/mapreduce/interface/ut/job_statistics_ut.cpp
index 90d40623c17..e0cf1ed9d7d 100644
--- a/yt/cpp/mapreduce/interface/ut/job_statistics_ut.cpp
+++ b/yt/cpp/mapreduce/interface/ut/job_statistics_ut.cpp
@@ -9,7 +9,7 @@ using namespace NYT;
 
 TEST(TJobStatisticsTest, Simple)
 {
-    const TString input = R"""(
+    const TStringBuf input = R"""(
         {
             "data" = {
                 "output" = {
@@ -65,7 +65,7 @@ TEST(TJobStatisticsTest, Simple)
 
 TEST(TJobStatisticsTest, OtherTypes)
 {
-    const TString input = R"""(
+    const TStringBuf input = R"""(
     {
         "time" = {
             "exec" = {
@@ -90,7 +90,7 @@ TEST(TJobStatisticsTest, OtherTypes)
 
 TEST(TJobStatisticsTest, Custom)
 {
-    const TString input = R"""(
+    const TStringBuf input = R"""(
         {
             "custom" = {
                 "some" = {
@@ -140,7 +140,7 @@ TEST(TJobStatisticsTest, Custom)
 
 TEST(TJobStatisticsTest, TaskNames)
 {
-    const TString input = R"""(
+    const TStringBuf input = R"""(
         {
             "data" = {
                 "output" = {
diff --git a/yt/yt/client/federated/unittests/cache_ut.cpp b/yt/yt/client/federated/unittests/cache_ut.cpp
index a880343a788..4039ef6ecc3 100644
--- a/yt/yt/client/federated/unittests/cache_ut.cpp
+++ b/yt/yt/client/federated/unittests/cache_ut.cpp
@@ -55,9 +55,9 @@ TEST(TFederatedClientsCacheTest, ConfigurationAndClusterUrlMismatch1)
     auto connectionConfig = New<TConnectionConfig>();
     connectionConfig->BundleName = "my_bundle";
     connectionConfig->RpcProxyConnections.push_back(New<NApi::NRpcProxy::TConnectionConfig>());
-    connectionConfig->RpcProxyConnections.back()->ClusterUrl = TString{"primary"};
+    connectionConfig->RpcProxyConnections.back()->ClusterUrl = "primary";
     connectionConfig->RpcProxyConnections.push_back(New<NApi::NRpcProxy::TConnectionConfig>());
-    connectionConfig->RpcProxyConnections.back()->ClusterUrl = TString{"secondary"};
+    connectionConfig->RpcProxyConnections.back()->ClusterUrl = "secondary";
 
     auto ytClientsCache = CreateFederatedClientsCache(
         connectionConfig,
@@ -75,11 +75,11 @@ TEST(TFederatedClientsCacheTest, ConfigurationAndClusterUrlMismatch2)
     auto connectionConfig = New<TConnectionConfig>();
     connectionConfig->BundleName = "my_bundle";
     connectionConfig->RpcProxyConnections.push_back(New<NApi::NRpcProxy::TConnectionConfig>());
-    connectionConfig->RpcProxyConnections.back()->ClusterUrl = TString{"primary"};
+    connectionConfig->RpcProxyConnections.back()->ClusterUrl = "primary";
     connectionConfig->RpcProxyConnections.push_back(New<NApi::NRpcProxy::TConnectionConfig>());
-    connectionConfig->RpcProxyConnections.back()->ClusterUrl = TString{"secondary"};
+    connectionConfig->RpcProxyConnections.back()->ClusterUrl = "secondary";
     connectionConfig->RpcProxyConnections.push_back(New<NApi::NRpcProxy::TConnectionConfig>());
-    connectionConfig->RpcProxyConnections.back()->ClusterUrl = TString{"tertiary"};
+    connectionConfig->RpcProxyConnections.back()->ClusterUrl = "tertiary";
 
     auto ytClientsCache = CreateFederatedClientsCache(
         connectionConfig,
@@ -97,9 +97,9 @@ TEST(TFederatedClientsCacheTest, ConfigurationMissingCluster)
     auto connectionConfig = New<TConnectionConfig>();
     connectionConfig->BundleName = "my_bundle";
     connectionConfig->RpcProxyConnections.push_back(New<NApi::NRpcProxy::TConnectionConfig>());
-    connectionConfig->RpcProxyConnections.back()->ClusterUrl = TString{"primary"};
+    connectionConfig->RpcProxyConnections.back()->ClusterUrl = "primary";
     connectionConfig->RpcProxyConnections.push_back(New<NApi::NRpcProxy::TConnectionConfig>());
-    connectionConfig->RpcProxyConnections.back()->ClusterUrl = TString{"secondary"};
+    connectionConfig->RpcProxyConnections.back()->ClusterUrl = "secondary";
 
     auto ytClientsCache = CreateFederatedClientsCache(
         connectionConfig,
diff --git a/yt/yt/client/federated/unittests/connection_ut.cpp b/yt/yt/client/federated/unittests/connection_ut.cpp
index 2034caa57f3..b9a04c22271 100644
--- a/yt/yt/client/federated/unittests/connection_ut.cpp
+++ b/yt/yt/client/federated/unittests/connection_ut.cpp
@@ -61,9 +61,9 @@ TEST(TFederatedConnectionTest, CreateClient)
         .WillOnce(Return(mockClientVla));
 
     EXPECT_CALL(*mockConnectionSas, GetLoggingTag())
-        .WillOnce(ReturnRefOfCopy(TString("sas")));
+        .WillOnce(ReturnRefOfCopy(std::string("sas")));
     EXPECT_CALL(*mockConnectionVla, GetLoggingTag())
-        .WillOnce(ReturnRefOfCopy(TString("vla")));
+        .WillOnce(ReturnRefOfCopy(std::string("vla")));
 
     auto finally = Finally([oldLocalHostName = NNet::GetLocalHostName()] {
         NNet::SetLocalHostName(oldLocalHostName);
@@ -126,9 +126,9 @@ TEST(TFederatedConnectionTest, CreateClientWhenOneClusterUnavailable)
         .WillOnce(Return(mockClientVla));
 
     EXPECT_CALL(*mockConnectionSas, GetLoggingTag())
-        .WillOnce(ReturnRefOfCopy(TString("sas")));
+        .WillOnce(ReturnRefOfCopy(std::string("sas")));
     EXPECT_CALL(*mockConnectionVla, GetLoggingTag())
-        .WillOnce(ReturnRefOfCopy(TString("vla")));
+        .WillOnce(ReturnRefOfCopy(std::string("vla")));
 
     auto finally = Finally([oldLocalHostName = NNet::GetLocalHostName()] {
         NNet::SetLocalHostName(oldLocalHostName);
diff --git a/yt/yt/client/table_client/unittests/logical_type_short_notation_ut.cpp b/yt/yt/client/table_client/unittests/logical_type_short_notation_ut.cpp
index cb810d64a9a..5d77fa274a2 100644
--- a/yt/yt/client/table_client/unittests/logical_type_short_notation_ut.cpp
+++ b/yt/yt/client/table_client/unittests/logical_type_short_notation_ut.cpp
@@ -245,7 +245,7 @@ TEST(TPrintDataTypesTest, TestEscape)
 {
     auto taggedType = TaggedLogicalType("'quote_and_single_slash\\", SimpleLogicalType(ESimpleLogicalValueType::Interval));
     auto typeString = ToString(*taggedType);
-    auto expected = TString("Tagged<Interval,'\\\'quote_and_single_slash\\\\'>");
+    auto expected = TStringBuf("Tagged<Interval,'\\\'quote_and_single_slash\\\\'>");
 
     EXPECT_EQ(typeString, expected);
 }
diff --git a/yt/yt/client/table_client/unittests/record_codegen_ut.cpp b/yt/yt/client/table_client/unittests/record_codegen_ut.cpp
index 4bdbbfd1eb4..0da0c41b4c2 100644
--- a/yt/yt/client/table_client/unittests/record_codegen_ut.cpp
+++ b/yt/yt/client/table_client/unittests/record_codegen_ut.cpp
@@ -12,7 +12,7 @@ using namespace NYson;
 ////////////////////////////////////////////////////////////////////////////////
 
 class TRecordCodegenTypeV3Test
-    : public ::testing::TestWithParam<std::pair<TString, TLogicalTypePtr>>
+    : public ::testing::TestWithParam<std::pair<std::string, TLogicalTypePtr>>
 { };
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -32,12 +32,12 @@ INSTANTIATE_TEST_SUITE_P(
     TRecordCodegenTypeV3Test,
     ::testing::Values(
         std::pair{
-            TString(R"({"type_name": "optional", "item": {"type_name": "list", "item": "string"}})"),
-            ConvertTo<TLogicalTypePtr>(TYsonString(TString("{type_name=optional;item={type_name=list;item=string}}")))
+            std::string(R"({"type_name": "optional", "item": {"type_name": "list", "item": "string"}})"),
+            ConvertTo<TLogicalTypePtr>(TYsonString(TStringBuf("{type_name=optional;item={type_name=list;item=string}}")))
         },
         std::pair{
-            TString(R"({"type_name": "int64"})"),
-            ConvertTo<TLogicalTypePtr>(TYsonString(TString("{type_name=\"int64\"}")))
+            std::string(R"({"type_name": "int64"})"),
+            ConvertTo<TLogicalTypePtr>(TYsonString(TStringBuf("{type_name=\"int64\"}")))
         }));
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/yt/yt/client/table_client/unittests/serialization_ut.cpp b/yt/yt/client/table_client/unittests/serialization_ut.cpp
index 4a6165f63c7..6fbef3b415d 100644
--- a/yt/yt/client/table_client/unittests/serialization_ut.cpp
+++ b/yt/yt/client/table_client/unittests/serialization_ut.cpp
@@ -23,10 +23,10 @@ namespace {
 
 TEST(TSchemaSerializationTest, ParseUsingNodeAndSerialize)
 {
-    const char* schemaString = "<strict=%true;unique_keys=%false>"
+    const TStringBuf schemaString = "<strict=%true;unique_keys=%false>"
         "[{name=a;required=%false;type=int64;};{deleted=%true;stable_name=b}]";
     TTableSchema schema;
-    Deserialize(schema, NYTree::ConvertToNode(NYson::TYsonString(TString(schemaString))));
+    Deserialize(schema, NYTree::ConvertToNode(NYson::TYsonString(schemaString)));
 
     EXPECT_EQ(1, std::ssize(schema.Columns()));
     EXPECT_EQ("a", schema.Columns()[0].Name());
@@ -43,7 +43,7 @@ TEST(TSchemaSerializationTest, ParseUsingNodeAndSerialize)
     auto ref = buffer.Flush();
     auto buf = ref.ToStringBuf();
 
-    EXPECT_EQ(TString(buf.data(), buf.size()),
+    EXPECT_EQ(TStringBuf(buf.data(), buf.size()),
 R"RR({"$attributes":{"strict":true,"unique_keys":false},"$value":[{"name":"a","required":false,"type":"int64","type_v3":{"type_name":"optional","item":"int64"}},{"stable_name":"b","deleted":true}]})RR");
 }
 
@@ -59,7 +59,7 @@ TEST(TSchemaSerializationTest, ParseEntityUsingNodeAndSerialize)
     auto ref = buffer.Flush();
     auto buf = ref.ToStringBuf();
 
-    EXPECT_EQ(TString(buf.data(), buf.size()), "null");
+    EXPECT_EQ(TStringBuf(buf.data(), buf.size()), "null");
 }
 
 TEST(TSchemaSerializationTest, Cursor)
@@ -82,12 +82,12 @@ TEST(TSchemaSerializationTest, Cursor)
 
 TEST(TSchemaSerializationTest, Deleted)
 {
-    const char* schemaString = "<strict=%true;unique_keys=%false>"
+    const TStringBuf schemaString = "<strict=%true;unique_keys=%false>"
         "[{name=a;required=%false;type=int64;};{deleted=%true;name=b}]";
 
     TTableSchema schema;
     EXPECT_THROW_WITH_SUBSTRING(
-        Deserialize(schema, NYTree::ConvertToNode(NYson::TYsonString(TString(schemaString)))),
+        Deserialize(schema, NYTree::ConvertToNode(NYson::TYsonString(schemaString))),
         "Stable name should be set for a deleted column");
 }
 
diff --git a/yt/yt/client/table_client/unittests/unversioned_row_ut.cpp b/yt/yt/client/table_client/unittests/unversioned_row_ut.cpp
index 1fe36b53417..6d086763ea2 100644
--- a/yt/yt/client/table_client/unittests/unversioned_row_ut.cpp
+++ b/yt/yt/client/table_client/unittests/unversioned_row_ut.cpp
@@ -21,11 +21,11 @@ TEST(TUnversionedOwningValueTest, DefaultCtor)
 
 TEST(TUnversionedOwningValueTest, String)
 {
-    TString string = "Hello world!";
+    std::string string = "Hello world!";
     TUnversionedOwningValue owningValue(MakeUnversionedStringValue(string));
     TUnversionedValue value = owningValue;
     ASSERT_EQ(owningValue.Type(), EValueType::String);
-    ASSERT_EQ(TString(value.Data.String, value.Length), string);
+    ASSERT_EQ(TStringBuf(value.Data.String, value.Length), string);
     ASSERT_EQ(owningValue.GetStringRef().ToStringBuf(), string);
 }
 
diff --git a/yt/yt/client/unittests/column_sort_schema_ut.cpp b/yt/yt/client/unittests/column_sort_schema_ut.cpp
index 897e4cdcc34..23c30f010e6 100644
--- a/yt/yt/client/unittests/column_sort_schema_ut.cpp
+++ b/yt/yt/client/unittests/column_sort_schema_ut.cpp
@@ -16,7 +16,7 @@ using namespace NYson;
 
 TEST(TColumnSortSchemaTest, Serialize)
 {
-    auto test = [] (TString name, ESortOrder sortOrder, TString expected) {
+    auto test = [] (std::string name, ESortOrder sortOrder, std::string expected) {
         TColumnSortSchema schema{
             .Name = name,
             .SortOrder = sortOrder
@@ -31,7 +31,7 @@ TEST(TColumnSortSchemaTest, Serialize)
 
 TEST(TColumnSortSchemaTest, Deserialize)
 {
-    auto test = [] (TString serialized, TString name, ESortOrder sortOrder) {
+    auto test = [] (std::string serialized, std::string name, ESortOrder sortOrder) {
         auto schema = ConvertTo<TColumnSortSchema>(TYsonString(serialized));
         EXPECT_EQ(schema.Name, name);
         EXPECT_EQ(schema.SortOrder, sortOrder);
diff --git a/yt/yt/client/unittests/composite_compare_ut.cpp b/yt/yt/client/unittests/composite_compare_ut.cpp
index c49ba11996a..23e552e8875 100644
--- a/yt/yt/client/unittests/composite_compare_ut.cpp
+++ b/yt/yt/client/unittests/composite_compare_ut.cpp
@@ -134,7 +134,7 @@ TEST(TCompositeCompareTest, TruncateYsonValue)
     checkTruncatedYson("[please; [take; [me; ha;];];]", "[please; [take; [me; haha; too; late]]]", 34);
     // The actual size of the resulting yson is only 4 bytes, but during truncation it is too hard to account for the fact that longer strings
     // take up more bytes for their length, since it is represented as a varint.
-    checkTruncatedYson("aa", TString(1000, 'a'), 5);
+    checkTruncatedYson("aa", std::string(1000, 'a'), 5);
     checkTruncatedYson("\"\"", "erase-me", 2);
 
     checkTruncatedYson("[[5; 7]; [1; 5; 4; 3]; [];]", "[[5; 7]; [1; 5; 4; 3]; [{hello=darkness}; 0; 0; 7]]", 10000);
diff --git a/yt/yt/client/unittests/key_bound_ut.cpp b/yt/yt/client/unittests/key_bound_ut.cpp
index e69fb833739..0bbad3350ce 100644
--- a/yt/yt/client/unittests/key_bound_ut.cpp
+++ b/yt/yt/client/unittests/key_bound_ut.cpp
@@ -23,7 +23,7 @@ TEST(TKeyBoundTest, Simple)
     builder.AddValue(MakeUnversionedDoubleValue(3.14, 0));
     builder.AddValue(MakeUnversionedInt64Value(-42, 1));
     builder.AddValue(MakeUnversionedUint64Value(27, 2));
-    TString str = "Foo";
+    std::string str = "Foo";
     builder.AddValue(MakeUnversionedStringValue(str, 3));
 
     auto owningRow = builder.FinishRow();
@@ -61,7 +61,7 @@ TEST(TKeyBoundTest, Helper)
     builder.AddValue(MakeUnversionedDoubleValue(3.14, 0));
     builder.AddValue(MakeUnversionedInt64Value(-42, 1));
     builder.AddValue(MakeUnversionedUint64Value(27, 2));
-    TString str = "Foo";
+    std::string str = "Foo";
     builder.AddValue(MakeUnversionedStringValue(str, 3));
 
     auto owningRow = builder.FinishRow();
@@ -225,7 +225,7 @@ TEST(TKeyBoundTest, Serialization)
     builder.AddValue(MakeUnversionedDoubleValue(3.14, 0));
     builder.AddValue(MakeUnversionedInt64Value(-42, 1));
     builder.AddValue(MakeUnversionedUint64Value(27, 2));
-    TString str = "Foo";
+    std::string str = "Foo";
     builder.AddValue(MakeUnversionedStringValue(str, 3));
 
     auto owningRow = builder.FinishRow();
diff --git a/yt/yt/client/unittests/key_ut.cpp b/yt/yt/client/unittests/key_ut.cpp
index 25fccea3dfd..4f632d04af6 100644
--- a/yt/yt/client/unittests/key_ut.cpp
+++ b/yt/yt/client/unittests/key_ut.cpp
@@ -19,7 +19,7 @@ TEST(TKeyTest, Simple)
     builder.AddValue(MakeUnversionedDoubleValue(3.14, 0));
     builder.AddValue(MakeUnversionedInt64Value(-42, 1));
     builder.AddValue(MakeUnversionedUint64Value(27, 2));
-    TString str = "Foo";
+    std::string str = "Foo";
     builder.AddValue(MakeUnversionedStringValue(str, 3));
 
     auto row = builder.FinishRow();
@@ -44,7 +44,7 @@ TEST(TKeyTest, Serialization)
     builder.AddValue(MakeUnversionedDoubleValue(3.14, 0));
     builder.AddValue(MakeUnversionedInt64Value(-42, 1));
     builder.AddValue(MakeUnversionedUint64Value(27, 2));
-    TString str = "Foo";
+    std::string str = "Foo";
     builder.AddValue(MakeUnversionedStringValue(str, 3));
     auto row = builder.FinishRow();
     TKey key = TKey::FromRow(row);
diff --git a/yt/yt/client/unittests/logical_type_ut.cpp b/yt/yt/client/unittests/logical_type_ut.cpp
index 25b0b6d4597..39b4f6da8d8 100644
--- a/yt/yt/client/unittests/logical_type_ut.cpp
+++ b/yt/yt/client/unittests/logical_type_ut.cpp
@@ -305,7 +305,7 @@ TEST(TLogicalTypeTest, TestIsComparable) {
     EXPECT_TRUE(IsComparable(Decimal(3, 2)));
 }
 
-TString CanonizeYsonString(TString input)
+TString CanonizeYsonString(TStringBuf input)
 {
     auto node = ConvertToNode(TYsonString(input));
     auto binaryYson = ConvertToYsonString(node);
@@ -329,7 +329,7 @@ class TLogicalTypeYson
     : public ::testing::TestWithParam<bool>
 {
 public:
-    TLogicalTypePtr FromTypeV3(TString yson)
+    TLogicalTypePtr FromTypeV3(TStringBuf yson)
     {
         const auto parseFromNode = GetParam();
         const auto ysonStr = TYsonStringBuf(yson, EYsonType::Node);
@@ -646,7 +646,7 @@ INSTANTIATE_TEST_SUITE_P(
 
 using TCombineTypeFunc = std::function<TLogicalTypePtr(const TLogicalTypePtr&)>;
 
-std::vector<std::pair<TString, TCombineTypeFunc>> CombineFunctions = {
+std::vector<std::pair<std::string, TCombineTypeFunc>> CombineFunctions = {
     {
         "optional",
         [] (const TLogicalTypePtr& type) {
@@ -724,7 +724,7 @@ TEST(TLogicalTypeTest, TestAllTypesInCombineFunctions)
 }
 
 class TCombineLogicalMetatypeTests
-    : public ::testing::TestWithParam<std::pair<TString, TCombineTypeFunc>>
+    : public ::testing::TestWithParam<std::pair<std::string, TCombineTypeFunc>>
 { };
 
 INSTANTIATE_TEST_SUITE_P(
@@ -1006,8 +1006,8 @@ TEST(TStructsValidationTest, TestRemovedFieldNames)
 
 ////////////////////////////////////////////////////////////////////////////////
 
-std::vector<std::vector<TString>> ParseData(TStringBuf data, int expectedFieldsCount) {
-    TString noComments;
+std::vector<std::vector<std::string>> ParseData(TStringBuf data, int expectedFieldsCount) {
+    std::string noComments;
     {
         TMemoryInput in(data);
         TString line;
@@ -1019,13 +1019,13 @@ std::vector<std::vector<TString>> ParseData(TStringBuf data, int expectedFieldsC
         }
     }
 
-    std::vector<std::vector<TString>> result;
+    std::vector<std::vector<std::string>> result;
     for (TStringBuf record : StringSplitter(noComments).SplitByString(";;")) {
         record = StripString(record);
         if (record.empty()) {
             continue;
         }
-        std::vector<TString> fields;
+        std::vector<std::string> fields;
         for (TStringBuf field : StringSplitter(record).SplitByString("::")) {
             fields.emplace_back(StripString(field));
         }
@@ -1043,12 +1043,8 @@ TEST(TTestLogicalTypesWithDataTest, GoodTypes)
 
     for (const auto& record : records) {
         const auto& typeYson = record.at(0);
-        // TODO(levysotsky): Remove when tz_* types are supported.
-        if (typeYson.Contains("tz_")) {
-            continue;
-        }
         const auto& typeText = record.at(1);
-        TString context = Format("text: %v\nyson: %v\n", typeText, typeYson);
+        auto context = Format("text: %v\nyson: %v\n", typeText, typeYson);
         auto wrapError = [&] (const std::exception& ex) {
             return yexception() << "Unexpected error: " << ex.what() << '\n' << context;
         };
@@ -1078,10 +1074,6 @@ TEST(TTestLogicalTypesWithDataTest, BadTypes)
 
     for (const auto& record : records) {
         const auto& typeYson = record.at(0);
-        // TODO(levysotsky): Remove when tz_* types are supported.
-        if (typeYson.Contains("tz_")) {
-            continue;
-        }
 
         EXPECT_THROW(ConvertTo<TLogicalTypePtr>(TYsonStringBuf(typeYson)), TErrorException);
     }
diff --git a/yt/yt/client/unittests/named_yson_token_ut.cpp b/yt/yt/client/unittests/named_yson_token_ut.cpp
index f0afa7ec727..6804818b1ce 100644
--- a/yt/yt/client/unittests/named_yson_token_ut.cpp
+++ b/yt/yt/client/unittests/named_yson_token_ut.cpp
@@ -61,7 +61,7 @@ TString CanonizeYson(TStringBuf yson)
     return result;
 }
 
-TString ConvertYson(
+std::string ConvertYson(
     bool namedToPositional,
     const TLogicalTypePtr& type,
     TStringBuf sourceYson)
@@ -110,7 +110,7 @@ void CheckYsonConversion(
     TStringBuf sourceYson,
     TStringBuf expectedConvertedYson)
 {
-    TString convertedYson;
+    std::string convertedYson;
     try {
         convertedYson = ConvertYson(namedToPositional, type, sourceYson);
     } catch (const std::exception& ex) {
@@ -135,13 +135,13 @@ void CheckYsonConversion(
 
 #define CHECK_NAMED_TO_POSITIONAL_THROWS(type, namedYson, exceptionSubstring) \
     do { \
-        TString tmp; \
+        std::string tmp; \
         EXPECT_THROW_WITH_SUBSTRING(ConvertYson(true, type, namedYson), exceptionSubstring); \
     } while (0)
 
 #define CHECK_POSITIONAL_TO_NAMED_THROWS(type, namedYson, exceptionSubstring) \
     do { \
-        TString tmp; \
+        std::string tmp; \
         EXPECT_THROW_WITH_SUBSTRING(ConvertYson(false, type, namedYson), exceptionSubstring); \
     } while (0)
 
diff --git a/yt/yt/client/unittests/read_limit_ut.cpp b/yt/yt/client/unittests/read_limit_ut.cpp
index 83a20aa040c..e367ba6a78a 100644
--- a/yt/yt/client/unittests/read_limit_ut.cpp
+++ b/yt/yt/client/unittests/read_limit_ut.cpp
@@ -29,7 +29,7 @@ NTableClient::TUnversionedOwningRow MakeRow(std::vector<int> values)
 ////////////////////////////////////////////////////////////////////////////////
 
 template <typename T>
-TString DumpToYson(T obj)
+std::string DumpToYson(T obj)
 {
     return ConvertToYsonString(obj, NYson::EYsonFormat::Text).ToString();
 }
diff --git a/yt/yt/client/unittests/replication_progress_ut.cpp b/yt/yt/client/unittests/replication_progress_ut.cpp
index 41746f544ce..55373e26526 100644
--- a/yt/yt/client/unittests/replication_progress_ut.cpp
+++ b/yt/yt/client/unittests/replication_progress_ut.cpp
@@ -417,7 +417,7 @@ TEST_P(TReplicationProgressSerializationTest, Simple)
 {
     const auto& params = GetParam();
     auto progress = ConvertTo<TReplicationProgress>(TYsonStringBuf(std::get<0>(params)));
-    auto expected = TString(std::get<1>(params));
+    auto expected = std::string(std::get<1>(params));
 
     auto result = ToString(progress);
 
@@ -463,7 +463,7 @@ TEST_P(TReplicationProgressProjectedSerializationTest, Simple)
     auto progress = ConvertTo<TReplicationProgress>(TYsonStringBuf(std::get<0>(params)));
     auto from = ConvertTo<TUnversionedOwningRow>(TYsonStringBuf(std::get<1>(params)));
     auto to = ConvertTo<TUnversionedOwningRow>(TYsonStringBuf(std::get<2>(params)));
-    auto expected = TString(std::get<3>(params));
+    auto expected = std::string(std::get<3>(params));
 
     TStringBuilder builder;
     FormatValue(&builder, progress, {}, {{from,  to}});
diff --git a/yt/yt/client/unittests/schema_ut.cpp b/yt/yt/client/unittests/schema_ut.cpp
index 02dd6ab3230..c621a80d2a7 100644
--- a/yt/yt/client/unittests/schema_ut.cpp
+++ b/yt/yt/client/unittests/schema_ut.cpp
@@ -23,7 +23,7 @@ using NYT::ToProto;
 
 ////////////////////////////////////////////////////////////////////////////////
 
-TColumnSchema ColumnFromYson(const TString& yson)
+TColumnSchema ColumnFromYson(const std::string& yson)
 {
     auto maybeDeletedColumn = ConvertTo<TMaybeDeletedColumnSchema>(TYsonStringBuf(yson));
     YT_VERIFY(!maybeDeletedColumn.Deleted());
@@ -283,48 +283,48 @@ TEST(TTableSchemaTest, ColumnSchemaValidation)
     expectBad(TColumnSchema(SystemColumnNamePrefix + "Name", EValueType::String));
 
     // Names longer than MaxColumnNameLength are not ok.
-    expectBad(TColumnSchema(TString(MaxColumnNameLength + 1, 'z'), EValueType::String));
+    expectBad(TColumnSchema(std::string(MaxColumnNameLength + 1, 'z'), EValueType::String));
 
     // Empty lock names are not ok.
     expectBad(
         TColumnSchema("Name", EValueType::String)
-            .SetLock(TString("")));
+            .SetLock(""));
 
     // Locks on key columns are not ok.
     expectBad(
         TColumnSchema("Name", EValueType::String)
             .SetSortOrder(ESortOrder::Ascending)
-            .SetLock(TString("LockName")));
+            .SetLock("LockName"));
 
     // Locks longer than MaxColumnLockLength are not ok.
     expectBad(
         TColumnSchema("Name", EValueType::String)
-            .SetLock(TString(MaxColumnLockLength + 1, 'z')));
+            .SetLock(std::string(MaxColumnLockLength + 1, 'z')));
 
     // Column type should be valid according to the ValidateSchemaValueType function.
     // Non-key columns can't be computed.
     expectBad(
         TColumnSchema("Name", EValueType::String)
-            .SetExpression(TString("SomeExpression")));
+            .SetExpression("SomeExpression"));
 
     // Key columns can't be aggregated.
     expectBad(
         TColumnSchema("Name", EValueType::String)
             .SetSortOrder(ESortOrder::Ascending)
-            .SetAggregate(TString("sum")));
+            .SetAggregate(std::string("sum")));
 
     ValidateColumnSchema(TColumnSchema("Name", EValueType::String));
     ValidateColumnSchema(TColumnSchema("Name", EValueType::Any));
     ValidateColumnSchema(
-        TColumnSchema(TString(256, 'z'), EValueType::String)
-            .SetLock(TString(256, 'z')));
+        TColumnSchema(std::string(256, 'z'), EValueType::String)
+            .SetLock(std::string(256, 'z')));
     ValidateColumnSchema(
         TColumnSchema("Name", EValueType::String)
             .SetSortOrder(ESortOrder::Ascending)
-            .SetExpression(TString("SomeExpression")));
+            .SetExpression("SomeExpression"));
     ValidateColumnSchema(
         TColumnSchema("Name", EValueType::String)
-            .SetAggregate(TString("sum")));
+            .SetAggregate(std::string("sum")));
 
     // Struct field validation
     expectBad(
@@ -333,7 +333,7 @@ TEST(TTableSchemaTest, ColumnSchemaValidation)
         }, /*removedFieldStableNames*/ {})));
     expectBad(
         TColumnSchema("Column", StructLogicalType({
-            {TString(257, 'a'), TString(257, 'a'), SimpleLogicalType(ESimpleLogicalValueType::Int8)}
+            {std::string(257, 'a'), std::string(257, 'a'), SimpleLogicalType(ESimpleLogicalValueType::Int8)}
         }, /*removedFieldStableNames*/ {})));
 
     expectBad(
diff --git a/yt/yt/client/unittests/unversioned_row_ut.cpp b/yt/yt/client/unittests/unversioned_row_ut.cpp
index 19c2bdabef7..dda2c260536 100644
--- a/yt/yt/client/unittests/unversioned_row_ut.cpp
+++ b/yt/yt/client/unittests/unversioned_row_ut.cpp
@@ -49,13 +49,13 @@ TEST(TUnversionedValueTest, TestConversionToYsonTokenWriter)
     }
     {
         auto value = MakeUnversionedStringValue("boo");
-        TString parsed;
-        EXPECT_NO_THROW(parsed = ConvertTo<TString>(TYsonString(convert(value))));
+        std::string parsed;
+        EXPECT_NO_THROW(parsed = ConvertTo<std::string>(TYsonString(convert(value))));
         EXPECT_EQ(parsed, "boo");
     }
     {
         auto value = MakeUnversionedNullValue();
-        TString str;
+        std::string str;
         EXPECT_NO_THROW(str = convert(value));
         EXPECT_EQ(str, "#");
     }
@@ -86,6 +86,8 @@ static_assert(TUnversionedValueConversionTraits<std::optional<i64>>::Inline, "i6
 static_assert(TUnversionedValueConversionTraits<std::optional<i64>>::Scalar, "i64? must be scalar.");
 static_assert(!TUnversionedValueConversionTraits<TString>::Inline, "TString must not be inline.");
 static_assert(TUnversionedValueConversionTraits<TString>::Scalar, "TString must be scalar.");
+static_assert(!TUnversionedValueConversionTraits<std::string>::Inline, "std::string must not be inline.");
+static_assert(TUnversionedValueConversionTraits<std::string>::Scalar, "std::string must be scalar.");
 static_assert(TUnversionedValueConversionTraits<TAnnotatedValue<i64>>::Scalar, "i64 must be scalar.");
 YT_DEFINE_STRONG_TYPEDEF(TStrongInt, i64);
 static_assert(TUnversionedValueConversionTraits<TStrongInt>::Scalar, "TStrongInt must be scalar.");
@@ -111,6 +113,7 @@ TEST(TMakeUnversionedOwningRowTest, SingleValue)
 {
     CheckSingleValue(TGuid::Create());
     CheckSingleValue(TString("hello"));
+    CheckSingleValue(std::string("hello"));
     CheckSingleValue(TStringBuf("hello"));
     CheckSingleValue(true);
     CheckSingleValue(TYsonString(TStringBuf("{a=1}")));
@@ -133,7 +136,7 @@ TEST(TMakeUnversionedOwningRowTest, CharPtr)
     auto row = MakeUnversionedOwningRow("test");
     EXPECT_EQ(1, row.GetCount());
     EXPECT_EQ(0, row[0].Id);
-    EXPECT_EQ("test", FromUnversionedValue<TString>(row[0]));
+    EXPECT_EQ("test", FromUnversionedValue<std::string>(row[0]));
 }
 
 TEST(TMakeUnversionedOwningRowTest, NullValue)
@@ -146,18 +149,18 @@ TEST(TMakeUnversionedOwningRowTest, NullValue)
 
 TEST(TMakeUnversionedOwningRowTest, Tuple)
 {
-    auto row = MakeUnversionedOwningRow(TString("hello"), true);
+    auto row = MakeUnversionedOwningRow(std::string("hello"), true);
     EXPECT_EQ(2, row.GetCount());
     EXPECT_EQ(0, row[0].Id);
-    EXPECT_EQ("hello", FromUnversionedValue<TString>(row[0]));
+    EXPECT_EQ("hello", FromUnversionedValue<std::string>(row[0]));
     EXPECT_EQ(1, row[1].Id);
     EXPECT_EQ(true, FromUnversionedValue<bool>(row[1]));
 }
 
 TEST(TMakeUnversionedOwningRowTest, FromUnversionedRow)
 {
-    auto row = MakeUnversionedOwningRow(TString("hello"), TStringBuf("world"), 123);
-    TString a;
+    auto row = MakeUnversionedOwningRow(std::string("hello"), TStringBuf("world"), 123);
+    std::string a;
     TStringBuf b;
     i16 c;
     FromUnversionedRow(row, &a, &b, &c);
@@ -168,8 +171,8 @@ TEST(TMakeUnversionedOwningRowTest, FromUnversionedRow)
 
 TEST(TMakeUnversionedOwningRowTest, TupleFromUnversionedRow)
 {
-    auto row = MakeUnversionedOwningRow(TString("hello"), TStringBuf("world"), 123);
-    auto [a, b, c] = FromUnversionedRow<TString, TStringBuf, i16>(row);
+    auto row = MakeUnversionedOwningRow(std::string("hello"), TStringBuf("world"), 123);
+    auto [a, b, c] = FromUnversionedRow<std::string, TStringBuf, i16>(row);
     EXPECT_EQ("hello", a);
     EXPECT_EQ("world", b);
     EXPECT_EQ(123, c);
@@ -178,7 +181,7 @@ TEST(TMakeUnversionedOwningRowTest, TupleFromUnversionedRow)
 TEST(TMakeUnversionedOwningRowTest, ExplicitIds)
 {
     auto row = MakeUnversionedOwningRow(
-        TAnnotatedValue{TString("hello"), 10},
+        TAnnotatedValue{std::string("hello"), 10},
         TAnnotatedValue{TStringBuf("world"), 20});
     EXPECT_EQ(2, row.GetCount());
     EXPECT_EQ(10, row[0].Id);
@@ -202,14 +205,14 @@ TEST(TUnversionedRowsBuilderTest, SomeValues)
     auto rows = builder.Build();
     EXPECT_EQ(2, std::ssize(rows));
     {
-        auto [i, s] = FromUnversionedRow<int, TString>(rows[0]);
+        auto [i, s] = FromUnversionedRow<int, std::string>(rows[0]);
         EXPECT_EQ(1, i);
         EXPECT_EQ("hello", s);
         EXPECT_EQ(0, rows[0][0].Id);
         EXPECT_EQ(1, rows[0][1].Id);
     }
     {
-        auto [i, s] = FromUnversionedRow<int, TString>(rows[1]);
+        auto [i, s] = FromUnversionedRow<int, std::string>(rows[1]);
         EXPECT_EQ(2, i);
         EXPECT_EQ("world", s);
         EXPECT_EQ(0, rows[1][0].Id);
@@ -226,14 +229,14 @@ TEST(TUnversionedRowsBuilderTest, AnnotatedValue)
     auto rows = builder.Build();
     EXPECT_EQ(3, std::ssize(rows));
     {
-        auto [i, s] = FromUnversionedRow<int, TString>(rows[0]);
+        auto [i, s] = FromUnversionedRow<int, std::string>(rows[0]);
         EXPECT_EQ(1, i);
         EXPECT_EQ("hello", s);
         EXPECT_EQ(10, rows[0][0].Id);
         EXPECT_EQ(20, rows[0][1].Id);
     }
     {
-        auto [i, s] = FromUnversionedRow<int, TString>(rows[1]);
+        auto [i, s] = FromUnversionedRow<int, std::string>(rows[1]);
         EXPECT_EQ(2, i);
         EXPECT_EQ("world", s);
         EXPECT_EQ(30, rows[1][0].Id);
diff --git a/yt/yt/client/unittests/uuid_text_ut.cpp b/yt/yt/client/unittests/uuid_text_ut.cpp
index 0a44ac498b7..04b5df36a77 100644
--- a/yt/yt/client/unittests/uuid_text_ut.cpp
+++ b/yt/yt/client/unittests/uuid_text_ut.cpp
@@ -11,11 +11,11 @@ void TestBidirectionalTextYqlUuidConversion(TStringBuf bytes, TStringBuf text)
 {
     std::array<char, UuidYqlTextSize> bytesToText;
     TextYqlUuidFromBytes(bytes, bytesToText.data());
-    EXPECT_EQ(TString(bytesToText.data(), bytesToText.size()), text);
+    EXPECT_EQ(TStringBuf(bytesToText.data(), bytesToText.size()), text);
 
     std::array<char, UuidBinarySize> textToBytes;
     TextYqlUuidToBytes(text, textToBytes.data());
-    EXPECT_EQ(TString(textToBytes.data(), textToBytes.size()), bytes);
+    EXPECT_EQ(TStringBuf(textToBytes.data(), textToBytes.size()), bytes);
 }
 
 TEST(TUuidConverterTest, TextYql)
@@ -45,7 +45,7 @@ TEST(TUuidConverterTest, InvalidTextYql)
 
 TEST(TUuidConverterTest, Guid)
 {
-    TString bytes = "\x01\x10\x20\x30\x40\x50\x60\x70\x80\x90\xa0\xb0\xc0\xd0\xe0\xf0";
+    TStringBuf bytes = "\x01\x10\x20\x30\x40\x50\x60\x70\x80\x90\xa0\xb0\xc0\xd0\xe0\xf0";
     auto guid = GuidFromBytes(bytes);
     std::array<char, UuidBinarySize> guidToBytes;
     GuidToBytes(guid, guidToBytes.data());
diff --git a/yt/yt/client/unittests/validate_logical_type_ut.cpp b/yt/yt/client/unittests/validate_logical_type_ut.cpp
index cf9b9774056..b84c91bd228 100644
--- a/yt/yt/client/unittests/validate_logical_type_ut.cpp
+++ b/yt/yt/client/unittests/validate_logical_type_ut.cpp
@@ -191,7 +191,7 @@ TEST(TValidateLogicalTypeTest, TestTimezoneType)
     EXPECT_NO_THROW(ValidateSimpleLogicalType<ESimpleLogicalValueType::TzDate>(correctValue));
 
     // Short buffer.
-    TString shortValue = "1";
+    std::string shortValue = "1";
     EXPECT_THROW_WITH_SUBSTRING(ValidateSimpleLogicalType<ESimpleLogicalValueType::TzDate>(shortValue), "Not a valid timezone type");
 
     // Wrong timezone.
diff --git a/yt/yt/client/unittests/ypath_ut.cpp b/yt/yt/client/unittests/ypath_ut.cpp
index ee753844564..4ff4868a765 100644
--- a/yt/yt/client/unittests/ypath_ut.cpp
+++ b/yt/yt/client/unittests/ypath_ut.cpp
@@ -49,7 +49,7 @@ public:
         return ConvertToYsonString(data, NYson::EYsonFormat::Text);
     }
 
-    void Set(const TYPath& path, const TString& value)
+    void Set(const TYPath& path, const std::string& value)
     {
         SyncYPathSet(RootService, path, TYsonString(value));
     }
@@ -69,7 +69,7 @@ public:
         return SyncYPathList(RootService, path);
     }
 
-    void Check(const TYPath& path, const TString& expected)
+    void Check(const TYPath& path, const std::string& expected)
     {
         TYsonString output = Get(path);
         EXPECT_TRUE(
@@ -916,7 +916,7 @@ TEST_F(TYPathTest, RowIndexInRanges)
 
 class TRichYPathToStringTest
     : public ::testing::Test
-    , public ::testing::WithParamInterface<TString>
+    , public ::testing::WithParamInterface<std::string>
 { };
 
 TEST_P(TRichYPathToStringTest, TestRichYPathToString)
@@ -947,12 +947,12 @@ class TEmbeddedYPathOpsTest
     : public ::testing::Test
 {
 public:
-    static INodePtr ParseNode(const TString& data)
+    static INodePtr ParseNode(const std::string& data)
     {
         return ConvertToNode(TYsonString(data));
     }
 
-    static void ExpectEqual(INodePtr node, const TString& ysonString)
+    static void ExpectEqual(INodePtr node, const std::string& ysonString)
     {
         EXPECT_EQ(ConvertToYsonString(node, EYsonFormat::Text).AsStringBuf(), ysonString);
     }
diff --git a/yt/yt/core/misc/unittests/configurable_singleton_ut.cpp b/yt/yt/core/misc/unittests/configurable_singleton_ut.cpp
index 8df85dcf789..d16a954c1e8 100644
--- a/yt/yt/core/misc/unittests/configurable_singleton_ut.cpp
+++ b/yt/yt/core/misc/unittests/configurable_singleton_ut.cpp
@@ -181,22 +181,22 @@ YT_DEFINE_RECONFIGURABLE_SINGLETON(
 
 TEST(TConfigurableSingletonTest, Run)
 {
-    auto config1 = ConvertTo<TSingletonsConfigPtr>(NYson::TYsonString(TString(R"""({
+    auto config1 = ConvertTo<TSingletonsConfigPtr>(NYson::TYsonString(TStringBuf(R"""({
         required = {
             speed = 123;
         };
     })""")));
-    auto config2 = ConvertTo<TSingletonsConfigPtr>(NYson::TYsonString(TString(R"""({
+    auto config2 = ConvertTo<TSingletonsConfigPtr>(NYson::TYsonString(TStringBuf(R"""({
         required = {
             speed = 124;
         };
     })""")));
-    auto dynamicConfig1 = ConvertTo<TSingletonsDynamicConfigPtr>(NYson::TYsonString(TString(R"""({
+    auto dynamicConfig1 = ConvertTo<TSingletonsDynamicConfigPtr>(NYson::TYsonString(TStringBuf(R"""({
         reconfigurable = {
             cost = 888;
         };
     })""")));
-    auto dynamicConfig2 = ConvertTo<TSingletonsDynamicConfigPtr>(NYson::TYsonString(TString(R"""({
+    auto dynamicConfig2 = ConvertTo<TSingletonsDynamicConfigPtr>(NYson::TYsonString(TStringBuf(R"""({
         reconfigurable = {
             cost = 999;
         };
diff --git a/yt/yt/core/phoenix/unittests/phoenix_ut.cpp b/yt/yt/core/phoenix/unittests/phoenix_ut.cpp
index 21a29da8358..fb2f9a5b37a 100644
--- a/yt/yt/core/phoenix/unittests/phoenix_ut.cpp
+++ b/yt/yt/core/phoenix/unittests/phoenix_ut.cpp
@@ -614,7 +614,7 @@ TEST(TPhoenixTest, CompatFieldSerializer)
         Save<int>(context, 123);
     });
 
-    auto loadSchema = ConvertTo<TUniverseSchemaPtr>(TYsonString(TString(R"""(
+    auto loadSchema = ConvertTo<TUniverseSchemaPtr>(TYsonString(TStringBuf(R"""(
         {
             types = [
                 {
@@ -686,7 +686,7 @@ TEST(TPhoenixTest, AddFieldAfterDeletedField)
         Save<int>(context, 123);
     });
 
-    auto removeBSchema = ConvertTo<TUniverseSchemaPtr>(TYsonString(TString(R"""(
+    auto removeBSchema = ConvertTo<TUniverseSchemaPtr>(TYsonString(TStringBuf(R"""(
         {
             types = [
                 {
@@ -747,7 +747,7 @@ TEST(TPhoenixTest, YsonDumpableDerived)
 
 namespace NCompatPointLoadSchema {
 
-const auto Schema = ConvertTo<TUniverseSchemaPtr>(TYsonString(TString(R"""(
+const auto Schema = ConvertTo<TUniverseSchemaPtr>(TYsonString(TStringBuf(R"""(
     {
         types = [
             {
@@ -833,7 +833,7 @@ TEST(TPhoenixTest, NativeLoadDerivedStructNoSchema)
         Save<int>(context, 456);
     });
 
-    auto loadSchema = ConvertTo<TUniverseSchemaPtr>(TYsonString(TString(R"""(
+    auto loadSchema = ConvertTo<TUniverseSchemaPtr>(TYsonString(TStringBuf(R"""(
         {
             types = [];
         }
diff --git a/yt/yt/library/decimal/unittests/decimal_ut.cpp b/yt/yt/library/decimal/unittests/decimal_ut.cpp
index d56f66af032..75dab97372d 100644
--- a/yt/yt/library/decimal/unittests/decimal_ut.cpp
+++ b/yt/yt/library/decimal/unittests/decimal_ut.cpp
@@ -9,7 +9,7 @@ namespace {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-TString RoundConvertText(TStringBuf textValue, int precision, int scale)
+std::string RoundConvertText(TStringBuf textValue, int precision, int scale)
 {
     auto binary = TDecimal::TextToBinary(textValue, precision, scale);
     return TDecimal::BinaryToText(binary, precision, scale);
@@ -318,22 +318,22 @@ public:
         return result;
     }
 
-    static TString GetTextNines(int precision)
+    static std::string GetTextNines(int precision)
     {
-        return TString(precision, '9');
+        return std::string(precision, '9');
     }
 
-    static TString GetTextMinusNines(int precision)
+    static std::string GetTextMinusNines(int precision)
     {
         return "-" + GetTextNines(precision);
     }
 
-    static TString GetTextZillion(int precision)
+    static std::string GetTextZillion(int precision)
     {
-        return "1" + TString(precision, '0');
+        return "1" + std::string(precision, '0');
     }
 
-    static TString GetTextMinusZillion(int precision)
+    static std::string GetTextMinusZillion(int precision)
     {
         return "-" + GetTextZillion(precision);
     }
diff --git a/yt/yt/library/named_value/named_value.cpp b/yt/yt/library/named_value/named_value.cpp
index fbec6589b6a..87489f14934 100644
--- a/yt/yt/library/named_value/named_value.cpp
+++ b/yt/yt/library/named_value/named_value.cpp
@@ -40,7 +40,7 @@ std::vector<TNamedValue> MakeNamedValueList(
     result.reserve(row.GetCount());
 
     for (const auto& value : row) {
-        auto namedValue = TNamedValue(TString(nameTable->GetNameOrThrow(value.Id)), TNamedValue::ExtractValue(value));
+        auto namedValue = TNamedValue(std::string(nameTable->GetNameOrThrow(value.Id)), TNamedValue::ExtractValue(value));
         result.push_back(std::move(namedValue));
     }
     return result;
@@ -61,7 +61,7 @@ TUnversionedValue TNamedValue::ToUnversionedValue(const TNameTablePtr& nameTable
             return MakeUnversionedDoubleValue(value, valueId);
         } else if constexpr (std::is_same_v<T, bool>) {
             return MakeUnversionedBooleanValue(value, valueId);
-        } else if constexpr (std::is_same_v<T, TString>) {
+        } else if constexpr (std::is_same_v<T, std::string>) {
             return MakeUnversionedStringValue(value, valueId);
         } else if constexpr (std::is_same_v<T, TAny>) {
             return MakeUnversionedAnyValue(value.Value, valueId);
@@ -107,11 +107,11 @@ TNamedValue::TValue TNamedValue::ExtractValue(const TUnversionedValue& value)
 TNamedValue::TValue TNamedValue::ToValue(EValueType valueType, TStringBuf value)
 {
     if (valueType == EValueType::String) {
-        return TString(value);
+        return std::string(value);
     } else if (valueType == EValueType::Any) {
-        return TAny{TString(value)};
+        return TAny{std::string(value)};
     } else if (valueType == EValueType::Composite) {
-        return TComposite{TString(value)};
+        return TComposite{std::string(value)};
     } else {
         YT_ABORT();
     }
diff --git a/yt/yt/library/named_value/named_value.h b/yt/yt/library/named_value/named_value.h
index c00081219ae..ceb79425467 100644
--- a/yt/yt/library/named_value/named_value.h
+++ b/yt/yt/library/named_value/named_value.h
@@ -43,46 +43,45 @@ class TNamedValue
 public:
     struct TAny
     {
-        TString Value;
+        std::string Value;
         friend bool operator ==(const TNamedValue::TAny& lhs, const TNamedValue::TAny& rhs) = default;
     };
 
     struct TComposite
     {
-        TString Value;
+        std::string Value;
         friend bool operator ==(const TNamedValue::TComposite& lhs, const TNamedValue::TComposite& rhs) = default;
     };
 
-    using TValue = std::variant<std::nullptr_t, i64, ui64, double, bool, TString, TAny, TComposite>;
+    using TValue = std::variant<std::nullptr_t, i64, ui64, double, bool, std::string, TAny, TComposite>;
 
 public:
     template <typename T>
-    TNamedValue(TString name, T value)
+    TNamedValue(std::string name, T value)
         : Name_(std::move(name))
         , Value_(std::move(value))
     { }
 
     template <>
-    TNamedValue(TString name, std::nullptr_t)
+    TNamedValue(std::string name, std::nullptr_t)
         : Name_(std::move(name))
-        , Value_()
     { }
 
     template <>
-    TNamedValue(TString name, unsigned value)
+    TNamedValue(std::string name, unsigned value)
         : Name_(std::move(name))
         , Value_(static_cast<ui64>(value))
     { }
 
     template <>
-    TNamedValue(TString name, TStringBuf value)
+    TNamedValue(std::string name, TStringBuf value)
         : Name_(std::move(name))
-        , Value_(TString(value))
+        , Value_(std::string(value))
     { }
 
-    TNamedValue(TString name, NTableClient::EValueType valueType, TStringBuf value)
+    TNamedValue(std::string name, NTableClient::EValueType valueType, TStringBuf value)
         : Name_(std::move(name))
-        , Value_(ToValue(valueType, TString(value)))
+        , Value_(ToValue(valueType, std::string(value)))
     { }
 
     NTableClient::TUnversionedValue ToUnversionedValue(const NTableClient::TNameTablePtr& nameTable) const;
@@ -93,7 +92,7 @@ private:
     TValue ToValue(NTableClient::EValueType valueType, TStringBuf value);
 
 private:
-    TString Name_;
+    std::string Name_;
     TValue Value_;
 
     friend bool operator ==(const TNamedValue& lhs, const TNamedValue& rhs) = default;
diff --git a/yt/yt/library/numeric/serialize/unittests/double_array_ut.cpp b/yt/yt/library/numeric/serialize/unittests/double_array_ut.cpp
index 52440b80c93..6850f88b46b 100644
--- a/yt/yt/library/numeric/serialize/unittests/double_array_ut.cpp
+++ b/yt/yt/library/numeric/serialize/unittests/double_array_ut.cpp
@@ -18,9 +18,9 @@ protected:
 TEST_F(TDoubleArrayTest, TestToString)
 {
     TDoubleArray<5> arr = {0, 1, 2, 3, 4};
-    TString result = "[0.000000 1.000000 2.000000 3.000000 4.000000]";
-    TString resultSmallPrecision = "[0.00 1.00 2.00 3.00 4.00]";
-    TString resultHighPrecision = "[0.0000000000 1.0000000000 2.0000000000 3.0000000000 4.0000000000]";
+    std::string result = "[0.000000 1.000000 2.000000 3.000000 4.000000]";
+    std::string resultSmallPrecision = "[0.00 1.00 2.00 3.00 4.00]";
+    std::string resultHighPrecision = "[0.0000000000 1.0000000000 2.0000000000 3.0000000000 4.0000000000]";
 
     // TODO(ignat)
     // EXPECT_EQ(result, ToString(arr));
@@ -30,7 +30,7 @@ TEST_F(TDoubleArrayTest, TestToString)
 
     std::stringstream ss1;
     ss1 << arr;
-    EXPECT_EQ(result, TString(ss1.str()));
+    EXPECT_EQ(result, ss1.str());
 
     // TODO(ignat)
     // TStringStream ss2;
diff --git a/yt/yt/library/numeric/unittests/binary_search_ut.cpp b/yt/yt/library/numeric/unittests/binary_search_ut.cpp
index f4335661744..c4a65adfd11 100644
--- a/yt/yt/library/numeric/unittests/binary_search_ut.cpp
+++ b/yt/yt/library/numeric/unittests/binary_search_ut.cpp
@@ -17,7 +17,7 @@ TEST_F(TBinarySearchTest, TestDoubleToBitset)
 {
     struct TTestCase
     {
-        TString name;
+        std::string name;
         double value;
         uint64_t bitset;
     };
@@ -76,7 +76,7 @@ TEST_F(TBinarySearchTest, TestFloatingPointLowerBound)
 {
     struct TTestCase
     {
-        TString name;
+        std::string name;
         double lo;
         double hi;
         std::function<bool(double)> predicate;
@@ -203,7 +203,7 @@ TEST_F(TBinarySearchTest, TestFloatingPointInverseLowerBound)
 {
     struct TTestCase
     {
-        TString name;
+        std::string name;
         double lo;
         double hi;
         std::function<bool(double)> predicate;
diff --git a/yt/yt/library/numeric/unittests/double_array_ut.cpp b/yt/yt/library/numeric/unittests/double_array_ut.cpp
index 755a84a9d92..dff07637438 100644
--- a/yt/yt/library/numeric/unittests/double_array_ut.cpp
+++ b/yt/yt/library/numeric/unittests/double_array_ut.cpp
@@ -47,7 +47,7 @@ TEST_F(TDoubleArrayTest, TestPlusMinus)
 {
     struct TTestCase
     {
-        TString Name;
+        std::string Name;
         TDoubleArray<4> Arg1;
         TDoubleArray<4> Arg2;
         TDoubleArray<4> ExpectedSum;
diff --git a/yt/yt/library/numeric/unittests/piecewise_linear_function_ut.cpp b/yt/yt/library/numeric/unittests/piecewise_linear_function_ut.cpp
index a16f410326c..3564a415205 100644
--- a/yt/yt/library/numeric/unittests/piecewise_linear_function_ut.cpp
+++ b/yt/yt/library/numeric/unittests/piecewise_linear_function_ut.cpp
@@ -162,7 +162,7 @@ TEST_F(TPiecewiseLinearFunctionTest, TestInterpolationProperties)
 TEST_F(TPiecewiseLinearFunctionTest, TestSortOrMergeImpl)
 {
     struct TTestCase {
-        TString Name;
+        std::string Name;
         std::vector<double> Input;
         int ExpectedNumberOfPivots;
         std::vector<double> ExpectedOutput;
@@ -313,7 +313,7 @@ TEST_F(TPiecewiseLinearFunctionTest, TestSortOrMergeImpl)
 TEST_F(TPiecewiseLinearFunctionTest, TestSum)
 {
     struct TTestCase {
-        TString Name;
+        std::string Name;
         std::vector<TPiecewiseLinearFunction<double>> Functions;
         double ExpectedLeftBound;
         double ExpectedRightBound;
@@ -506,7 +506,7 @@ TEST_F(TPiecewiseLinearFunctionTest, TestSum)
 TEST_F(TPiecewiseLinearFunctionTest, TestPointwiseMin)
 {
     struct TTestCase {
-        TString Name;
+        std::string Name;
         std::vector<TPiecewiseLinearFunction<double>> Functions;
         double ExpectedLeftBound;
         double ExpectedRightBound;
@@ -755,7 +755,7 @@ TEST_F(TPiecewiseLinearFunctionTest, TestPointwiseMin)
 TEST_F(TPiecewiseLinearFunctionTest, TestCompose)
 {
     struct TTestCase {
-        TString Name;
+        std::string Name;
         TPiecewiseLinearFunction<double> Lhs;
         TPiecewiseLinearFunction<double> Rhs;
         std::vector<TSample> Samples;
@@ -1015,7 +1015,7 @@ TEST_F(TPiecewiseLinearFunctionTest, TestCompose)
 TEST_F(TPiecewiseLinearFunctionTest, TestTransformations)
 {
     struct TTestCase {
-        TString Name;
+        std::string Name;
         TPiecewiseLinearFunction<double> Function;
         TPiecewiseLinearFunction<double> ExpectedTransposedFunction;
     };
@@ -1062,7 +1062,7 @@ TEST_F(TPiecewiseLinearFunctionTest, TestPiecewiseSegmentScalar)
     };
 
     struct TTestCase {
-        TString Name;
+        std::string Name;
         TPiecewiseSegment<double> Segment;
         std::pair<double, double> ExpectedBounds;
         std::pair<double, double> ExpectedValues;
@@ -1241,7 +1241,7 @@ TEST_F(TPiecewiseLinearFunctionTest, TestPiecewiseSegmentTransformationsScalar)
     };
 
     struct TTestCase {
-        TString Name;
+        std::string Name;
         TPiecewiseSegment<double> Segment;
         TPiecewiseSegment<double> ExpectedTransposedSegment;
         std::vector<TScaledSegment> ExpectedScaledSegments;
diff --git a/yt/yt/library/profiling/unittests/encoder_ut.cpp b/yt/yt/library/profiling/unittests/encoder_ut.cpp
index 5f74fc50d46..0faacabd595 100644
--- a/yt/yt/library/profiling/unittests/encoder_ut.cpp
+++ b/yt/yt/library/profiling/unittests/encoder_ut.cpp
@@ -43,7 +43,7 @@ TEST(TSensorEncoderTest, Encode)
 
     auto sensorDump = encoder.BuildSensorDump();
 
-    TString sensorDumpText;
+    TProtoStringType sensorDumpText;
     EXPECT_TRUE(NProtoBuf::TextFormat::PrintToString(sensorDump, &sensorDumpText));
     Cerr << "Sensor dump:\n" << sensorDumpText << Endl;
 
diff --git a/yt/yt/library/profiling/unittests/exporter_ut.cpp b/yt/yt/library/profiling/unittests/exporter_ut.cpp
index 907f2902161..16920aacd9a 100644
--- a/yt/yt/library/profiling/unittests/exporter_ut.cpp
+++ b/yt/yt/library/profiling/unittests/exporter_ut.cpp
@@ -140,14 +140,14 @@ TEST(TSolomonExporterTest, ReadSensorsFilter)
     TGauge cache_size = TProfiler("/cache/", "", {}, registry).Gauge("size");
     TGauge responses = TProfiler("/requests/", "", {}, registry).Gauge("responses");
 
-    auto isSensorInShard = [&exporter] (const TString& shardName, const TString& sensor) -> bool {
-        std::optional<TString> out = exporter->ReadJson({}, shardName);
+    auto isSensorInShard = [&exporter] (const std::string& shardName, const std::string& sensor) -> bool {
+        std::optional<std::string> out = exporter->ReadJson({}, shardName);
         if (!out) {
             return false;
         }
 
-        const TString& sensors = out.value();
-        return sensors.Contains(sensor);
+        const std::string& sensors = out.value();
+        return sensors.contains(sensor);
     };
 
     ASSERT_FALSE(isSensorInShard("/uptime/", "uptime"));
@@ -210,12 +210,12 @@ TEST(TSolomonExporterTest, ReadSensorsStripSensorsOption)
     Sleep(TDuration::Seconds(5));
 
     // WO Strip option
-    std::optional<TString> out = exporter->ReadJson({}, "/uptime/");
+    std::optional<std::string> out = exporter->ReadJson({}, "/uptime/");
     ASSERT_TRUE(out);
 
-    TString& sensors = out.value();
-    ASSERT_TRUE(sensors.Contains("uptime"));
-    ASSERT_TRUE(sensors.Contains("uptime.")); // not "/uptime/" Reason: sensor rename
+    std::string& sensors = out.value();
+    ASSERT_TRUE(sensors.contains("uptime"));
+    ASSERT_TRUE(sensors.contains("uptime.")); // not "/uptime/" Reason: sensor rename
 
     // With Strip option
     TReadOptions options;
@@ -224,8 +224,8 @@ TEST(TSolomonExporterTest, ReadSensorsStripSensorsOption)
     ASSERT_TRUE(out);
 
     sensors = out.value();
-    ASSERT_TRUE(sensors.Contains("uptime"));
-    ASSERT_FALSE(sensors.Contains("uptime."));
+    ASSERT_TRUE(sensors.contains("uptime"));
+    ASSERT_FALSE(sensors.contains("uptime."));
 
     exporter->Stop();
 }