diff --git a/internal/tlcodegen/test/gen/cases_cpp/benchmarks/details.cpp b/internal/tlcodegen/test/gen/cases_cpp/benchmarks/details.cpp
index 897bd542..5d783054 100644
--- a/internal/tlcodegen/test/gen/cases_cpp/benchmarks/details.cpp
+++ b/internal/tlcodegen/test/gen/cases_cpp/benchmarks/details.cpp
@@ -317,10 +317,8 @@ void tl2::details::BenchmarksVrutoyPositionsReset(::tl2::benchmarks::VrutoyPosit
 }
 
 bool tl2::details::BenchmarksVrutoyPositionsWriteJSON(std::ostream& s, const ::tl2::benchmarks::VrutoyPositions& item, uint32_t nat_n) {
-	auto add_comma = false;
 	s << "{";
 	if ((item.next_positions.size() != 0) || (nat_n != 0)) {
-		add_comma = true;
 		s << "\"next_positions\":";
 		if (!::tl2::details::BuiltinTupleBenchmarksVruPositionWriteJSON(s, item.next_positions, nat_n)) { return false; }
 	}
@@ -378,9 +376,7 @@ void tl2::details::BenchmarksVrutoyTopLevelContainerReset(::tl2::benchmarks::Vru
 }
 
 bool tl2::details::BenchmarksVrutoyTopLevelContainerWriteJSON(std::ostream& s, const ::tl2::benchmarks::VrutoyTopLevelContainer& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"value\":";
 	if (!::tl2::details::BenchmarksVrutoyTopLevelUnionWriteJSON(s, item.value)) { return false; }
 	s << "}";
@@ -574,10 +570,8 @@ void tl2::details::BenchmarksVrutoytopLevelUnionBigReset(::tl2::benchmarks::Vrut
 }
 
 bool tl2::details::BenchmarksVrutoytopLevelUnionBigWriteJSON(std::ostream& s, const ::tl2::benchmarks::VrutoytopLevelUnionBig& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.next_positions.size() != 0) {
-		add_comma = true;
 		s << "\"next_positions\":";
 		if (!::tl2::details::BuiltinVectorBenchmarksVruPositionWriteJSON(s, item.next_positions)) { return false; }
 	}
diff --git a/internal/tlcodegen/test/gen/cases_cpp/cases/details.cpp b/internal/tlcodegen/test/gen/cases_cpp/cases/details.cpp
index 7c7950b7..8c251eec 100644
--- a/internal/tlcodegen/test/gen/cases_cpp/cases/details.cpp
+++ b/internal/tlcodegen/test/gen/cases_cpp/cases/details.cpp
@@ -1178,10 +1178,8 @@ void tl2::details::CasesTestDictAnyReset(::tl2::cases::TestDictAny& item) {
 }
 
 bool tl2::details::CasesTestDictAnyWriteJSON(std::ostream& s, const ::tl2::cases::TestDictAny& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.dict.size() != 0) {
-		add_comma = true;
 		s << "\"dict\":";
 		if (!::tl2::details::DictionaryAnyDoubleIntWriteJSON(s, item.dict)) { return false; }
 	}
@@ -1239,10 +1237,8 @@ void tl2::details::CasesTestDictIntReset(::tl2::cases::TestDictInt& item) {
 }
 
 bool tl2::details::CasesTestDictIntWriteJSON(std::ostream& s, const ::tl2::cases::TestDictInt& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.dict.size() != 0) {
-		add_comma = true;
 		s << "\"dict\":";
 		if (!::tl2::details::BuiltinVectorDictionaryFieldAnyIntIntWriteJSON(s, item.dict)) { return false; }
 	}
@@ -1300,10 +1296,8 @@ void tl2::details::CasesTestDictStringReset(::tl2::cases::TestDictString& item)
 }
 
 bool tl2::details::CasesTestDictStringWriteJSON(std::ostream& s, const ::tl2::cases::TestDictString& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.dict.size() != 0) {
-		add_comma = true;
 		s << "\"dict\":";
 		if (!::tl2::details::DictionaryIntWriteJSON(s, item.dict)) { return false; }
 	}
@@ -1571,9 +1565,7 @@ void tl2::details::CasesTestEnumContainerReset(::tl2::cases::TestEnumContainer&
 }
 
 bool tl2::details::CasesTestEnumContainerWriteJSON(std::ostream& s, const ::tl2::cases::TestEnumContainer& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"value\":";
 	if (!::tl2::details::CasesTestEnumWriteJSON(s, item.value)) { return false; }
 	s << "}";
@@ -1742,10 +1734,8 @@ void tl2::details::CasesTestMaybeReset(::tl2::cases::TestMaybe& item) {
 }
 
 bool tl2::details::CasesTestMaybeWriteJSON(std::ostream& s, const ::tl2::cases::TestMaybe& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.value.has_value()) {
-		add_comma = true;
 		s << "\"value\":";
 		if (!::tl2::details::IntMaybeWriteJSON(s, item.value)) { return false; }
 	}
@@ -2106,9 +2096,7 @@ void tl2::details::CasesTestTupleReset(::tl2::cases::TestTuple& item) {
 }
 
 bool tl2::details::CasesTestTupleWriteJSON(std::ostream& s, const ::tl2::cases::TestTuple& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"tpl\":";
 	if (!::tl2::details::BuiltinTuple4IntWriteJSON(s, item.tpl)) { return false; }
 	s << "}";
@@ -2240,10 +2228,8 @@ void tl2::details::CasesTestUnion1Reset(::tl2::cases::TestUnion1& item) {
 }
 
 bool tl2::details::CasesTestUnion1WriteJSON(std::ostream& s, const ::tl2::cases::TestUnion1& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.value != 0) {
-		add_comma = true;
 		s << "\"value\":";
 		s << item.value;
 	}
@@ -2301,10 +2287,8 @@ void tl2::details::CasesTestUnion2Reset(::tl2::cases::TestUnion2& item) {
 }
 
 bool tl2::details::CasesTestUnion2WriteJSON(std::ostream& s, const ::tl2::cases::TestUnion2& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.value.size() != 0) {
-		add_comma = true;
 		s << "\"value\":";
 		s << "\"" << item.value << "\"";
 	}
@@ -2362,9 +2346,7 @@ void tl2::details::CasesTestUnionContainerReset(::tl2::cases::TestUnionContainer
 }
 
 bool tl2::details::CasesTestUnionContainerWriteJSON(std::ostream& s, const ::tl2::cases::TestUnionContainer& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"value\":";
 	if (!::tl2::details::CasesTestUnionWriteJSON(s, item.value)) { return false; }
 	s << "}";
@@ -2421,10 +2403,8 @@ void tl2::details::CasesTestVectorReset(::tl2::cases::TestVector& item) {
 }
 
 bool tl2::details::CasesTestVectorWriteJSON(std::ostream& s, const ::tl2::cases::TestVector& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.arr.size() != 0) {
-		add_comma = true;
 		s << "\"arr\":";
 		if (!::tl2::details::BuiltinVectorIntWriteJSON(s, item.arr)) { return false; }
 	}
@@ -2456,7 +2436,7 @@ bool tl2::details::IntMaybeWriteJSON(std::ostream & s, const std::optional<int32
 	s << "{";
 	if (item) {
 		s << "\"ok\":true";
-		if(*item != 0) {
+		if((*item) != 0) {
 			s << ",\"value\":";
 			s << *item;
 		}
diff --git a/internal/tlcodegen/test/gen/cases_cpp/cases_bytes/details.cpp b/internal/tlcodegen/test/gen/cases_cpp/cases_bytes/details.cpp
index 033bf4dd..99e9a5a9 100644
--- a/internal/tlcodegen/test/gen/cases_cpp/cases_bytes/details.cpp
+++ b/internal/tlcodegen/test/gen/cases_cpp/cases_bytes/details.cpp
@@ -269,10 +269,8 @@ void tl2::details::CasesBytesTestDictAnyReset(::tl2::cases_bytes::TestDictAny& i
 }
 
 bool tl2::details::CasesBytesTestDictAnyWriteJSON(std::ostream& s, const ::tl2::cases_bytes::TestDictAny& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.dict.size() != 0) {
-		add_comma = true;
 		s << "\"dict\":";
 		if (!::tl2::details::DictionaryAnyDoubleIntWriteJSON(s, item.dict)) { return false; }
 	}
@@ -330,10 +328,8 @@ void tl2::details::CasesBytesTestDictIntReset(::tl2::cases_bytes::TestDictInt& i
 }
 
 bool tl2::details::CasesBytesTestDictIntWriteJSON(std::ostream& s, const ::tl2::cases_bytes::TestDictInt& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.dict.size() != 0) {
-		add_comma = true;
 		s << "\"dict\":";
 		if (!::tl2::details::BuiltinVectorDictionaryFieldAnyIntIntWriteJSON(s, item.dict)) { return false; }
 	}
@@ -391,10 +387,8 @@ void tl2::details::CasesBytesTestDictStringReset(::tl2::cases_bytes::TestDictStr
 }
 
 bool tl2::details::CasesBytesTestDictStringWriteJSON(std::ostream& s, const ::tl2::cases_bytes::TestDictString& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.dict.size() != 0) {
-		add_comma = true;
 		s << "\"dict\":";
 		if (!::tl2::details::DictionaryIntWriteJSON(s, item.dict)) { return false; }
 	}
@@ -452,10 +446,8 @@ void tl2::details::CasesBytesTestDictStringStringReset(::tl2::cases_bytes::TestD
 }
 
 bool tl2::details::CasesBytesTestDictStringStringWriteJSON(std::ostream& s, const ::tl2::cases_bytes::TestDictStringString& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.dict.size() != 0) {
-		add_comma = true;
 		s << "\"dict\":";
 		if (!::tl2::details::DictionaryStringWriteJSON(s, item.dict)) { return false; }
 	}
@@ -723,9 +715,7 @@ void tl2::details::CasesBytesTestEnumContainerReset(::tl2::cases_bytes::TestEnum
 }
 
 bool tl2::details::CasesBytesTestEnumContainerWriteJSON(std::ostream& s, const ::tl2::cases_bytes::TestEnumContainer& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"value\":";
 	if (!::tl2::details::CasesTestEnumWriteJSON(s, item.value)) { return false; }
 	s << "}";
@@ -782,9 +772,7 @@ void tl2::details::CasesBytesTestTupleReset(::tl2::cases_bytes::TestTuple& item)
 }
 
 bool tl2::details::CasesBytesTestTupleWriteJSON(std::ostream& s, const ::tl2::cases_bytes::TestTuple& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"tpl\":";
 	if (!::tl2::details::BuiltinTuple4StringWriteJSON(s, item.tpl)) { return false; }
 	s << "}";
@@ -841,10 +829,8 @@ void tl2::details::CasesBytesTestVectorReset(::tl2::cases_bytes::TestVector& ite
 }
 
 bool tl2::details::CasesBytesTestVectorWriteJSON(std::ostream& s, const ::tl2::cases_bytes::TestVector& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.arr.size() != 0) {
-		add_comma = true;
 		s << "\"arr\":";
 		if (!::tl2::details::BuiltinVectorStringWriteJSON(s, item.arr)) { return false; }
 	}
diff --git a/internal/tlcodegen/test/gen/schema_cpp/__common_namespace/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/__common_namespace/details.cpp
index 2cf9572a..5a08d998 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/__common_namespace/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/__common_namespace/details.cpp
@@ -187,9 +187,7 @@ void tl2::details::BoxedArrayReset(::tl2::BoxedArray& item) {
 }
 
 bool tl2::details::BoxedArrayWriteJSON(std::ostream& s, const ::tl2::BoxedArray& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"x\":";
 	if (!::tl2::details::MyBoxedArrayWriteJSON(s, item.x)) { return false; }
 	s << "}";
@@ -262,10 +260,8 @@ void tl2::details::BoxedIntReset(::tl2::BoxedInt& item) {
 }
 
 bool tl2::details::BoxedIntWriteJSON(std::ostream& s, const ::tl2::BoxedInt& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		s << item.x;
 	}
@@ -343,10 +339,8 @@ void tl2::details::BoxedStringReset(::tl2::BoxedString& item) {
 }
 
 bool tl2::details::BoxedStringWriteJSON(std::ostream& s, const ::tl2::BoxedString& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x.size() != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		s << "\"" << item.x << "\"";
 	}
@@ -424,9 +418,7 @@ void tl2::details::BoxedTupleReset(::tl2::BoxedTuple& item) {
 }
 
 bool tl2::details::BoxedTupleWriteJSON(std::ostream& s, const ::tl2::BoxedTuple& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"x\":";
 	if (!::tl2::details::BuiltinTuple3IntWriteJSON(s, item.x)) { return false; }
 	s << "}";
@@ -595,9 +587,7 @@ void tl2::details::BoxedTupleSlice2Reset(::tl2::BoxedTupleSlice2& item) {
 }
 
 bool tl2::details::BoxedTupleSlice2WriteJSON(std::ostream& s, const ::tl2::BoxedTupleSlice2& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"x\":";
 	if (!::tl2::details::MyBoxedTupleSliceWriteJSON(s, item.x)) { return false; }
 	s << "}";
@@ -762,10 +752,8 @@ void tl2::details::BoxedVector32Reset(::tl2::BoxedVector32& item) {
 }
 
 bool tl2::details::BoxedVector32WriteJSON(std::ostream& s, const ::tl2::BoxedVector32& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x.size() != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		if (!::tl2::details::BuiltinVectorIntWriteJSON(s, item.x)) { return false; }
 	}
@@ -843,10 +831,8 @@ void tl2::details::BoxedVector32BoxedElemReset(::tl2::BoxedVector32BoxedElem& it
 }
 
 bool tl2::details::BoxedVector32BoxedElemWriteJSON(std::ostream& s, const ::tl2::BoxedVector32BoxedElem& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x.size() != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		if (!::tl2::details::BuiltinVectorIntBoxedWriteJSON(s, item.x)) { return false; }
 	}
@@ -924,10 +910,8 @@ void tl2::details::BoxedVector64Reset(::tl2::BoxedVector64& item) {
 }
 
 bool tl2::details::BoxedVector64WriteJSON(std::ostream& s, const ::tl2::BoxedVector64& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x.size() != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		if (!::tl2::details::BuiltinVectorLongBoxedWriteJSON(s, item.x)) { return false; }
 	}
@@ -2195,10 +2179,8 @@ void tl2::details::GetDoubleReset(::tl2::GetDouble& item) {
 }
 
 bool tl2::details::GetDoubleWriteJSON(std::ostream& s, const ::tl2::GetDouble& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		s << item.x;
 	}
@@ -2276,10 +2258,8 @@ void tl2::details::GetFloatReset(::tl2::GetFloat& item) {
 }
 
 bool tl2::details::GetFloatWriteJSON(std::ostream& s, const ::tl2::GetFloat& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		s << item.x;
 	}
@@ -2355,9 +2335,7 @@ void tl2::details::GetMaybeIfaceReset(::tl2::GetMaybeIface& item) {
 }
 
 bool tl2::details::GetMaybeIfaceWriteJSON(std::ostream& s, const ::tl2::GetMaybeIface& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"x\":";
 	if (!::tl2::details::Service1ValueWriteJSON(s, item.x)) { return false; }
 	s << "}";
@@ -2430,10 +2408,8 @@ void tl2::details::GetMyDictOfIntReset(::tl2::GetMyDictOfInt& item) {
 }
 
 bool tl2::details::GetMyDictOfIntWriteJSON(std::ostream& s, const ::tl2::GetMyDictOfInt& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x.size() != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		if (!::tl2::details::MyDictOfIntWriteJSON(s, item.x)) { return false; }
 	}
@@ -2507,10 +2483,8 @@ void tl2::details::GetMyDoubleReset(::tl2::GetMyDouble& item) {
 }
 
 bool tl2::details::GetMyDoubleWriteJSON(std::ostream& s, const ::tl2::GetMyDouble& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		if (!::tl2::details::MyDoubleWriteJSON(s, item.x)) { return false; }
 	}
@@ -2584,9 +2558,7 @@ void tl2::details::GetMyValueReset(::tl2::GetMyValue& item) {
 }
 
 bool tl2::details::GetMyValueWriteJSON(std::ostream& s, const ::tl2::GetMyValue& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"x\":";
 	if (!::tl2::details::MyValueWriteJSON(s, item.x)) { return false; }
 	s << "}";
@@ -2751,9 +2723,7 @@ void tl2::details::GetStatsReset(::tl2::GetStats& item) {
 }
 
 bool tl2::details::GetStatsWriteJSON(std::ostream& s, const ::tl2::GetStats& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"x\":";
 	if (!::tl2::details::TasksQueueTypeStatsWriteJSON(s, item.x)) { return false; }
 	s << "}";
@@ -2829,7 +2799,7 @@ bool tl2::details::IntMaybeWriteJSON(std::ostream & s, const std::optional<int32
 	s << "{";
 	if (item) {
 		s << "\"ok\":true";
-		if(*item != 0) {
+		if((*item) != 0) {
 			s << ",\"value\":";
 			s << *item;
 		}
@@ -2889,10 +2859,8 @@ void tl2::details::IntegerReset(::tl2::Integer& item) {
 }
 
 bool tl2::details::IntegerWriteJSON(std::ostream& s, const ::tl2::Integer& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.value != 0) {
-		add_comma = true;
 		s << "\"value\":";
 		s << item.value;
 	}
@@ -2950,10 +2918,8 @@ void tl2::details::Issue3498Reset(::tl2::Issue3498& item) {
 }
 
 bool tl2::details::Issue3498WriteJSON(std::ostream& s, const ::tl2::Issue3498& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x.size() != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		if (!::tl2::details::BuiltinVectorEitherService6ErrorVectorService6FindResultRowWriteJSON(s, item.x)) { return false; }
 	}
@@ -2988,10 +2954,8 @@ void tl2::details::LeftIntVectorService6FindWithBoundsResultReset(::tl2::Left<in
 }
 
 bool tl2::details::LeftIntVectorService6FindWithBoundsResultWriteJSON(std::ostream& s, const ::tl2::Left<int32_t, std::vector<::tl2::service6::FindWithBoundsResult>>& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.value != 0) {
-		add_comma = true;
 		s << "\"value\":";
 		s << item.value;
 	}
@@ -3024,9 +2988,7 @@ void tl2::details::LeftService6ErrorVectorService6FindResultRowReset(::tl2::Left
 }
 
 bool tl2::details::LeftService6ErrorVectorService6FindResultRowWriteJSON(std::ostream& s, const ::tl2::Left<::tl2::service6::Error, std::vector<::tl2::service6::FindResultRow>>& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"value\":";
 	if (!::tl2::details::Service6ErrorWriteJSON(s, item.value)) { return false; }
 	s << "}";
@@ -3188,9 +3150,7 @@ void tl2::details::MyBoxedArrayReset(::tl2::MyBoxedArray& item) {
 }
 
 bool tl2::details::MyBoxedArrayWriteJSON(std::ostream& s, const ::tl2::MyBoxedArray& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"data\":";
 	if (!::tl2::details::BuiltinTuple2IntBoxedWriteJSON(s, item.data)) { return false; }
 	s << "}";
@@ -3323,10 +3283,8 @@ void tl2::details::MyBoxedVectorSliceReset(::tl2::MyBoxedVectorSlice& item) {
 }
 
 bool tl2::details::MyBoxedVectorSliceWriteJSON(std::ostream& s, const ::tl2::MyBoxedVectorSlice& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.data.size() != 0) {
-		add_comma = true;
 		s << "\"data\":";
 		if (!::tl2::details::BuiltinVectorIntBoxedWriteJSON(s, item.data)) { return false; }
 	}
@@ -3446,10 +3404,8 @@ void tl2::details::MyIntReset(::tl2::MyInt& item) {
 }
 
 bool tl2::details::MyIntWriteJSON(std::ostream& s, const ::tl2::MyInt& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.val1 != 0) {
-		add_comma = true;
 		s << "\"val1\":";
 		s << item.val1;
 	}
@@ -3567,9 +3523,7 @@ void tl2::details::MyMcValueReset(::tl2::MyMcValue& item) {
 }
 
 bool tl2::details::MyMcValueWriteJSON(std::ostream& s, const ::tl2::MyMcValue& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"x\":";
 	if (!::tl2::details::Service1ValueWriteJSON(s, item.x)) { return false; }
 	s << "}";
@@ -3626,9 +3580,7 @@ void tl2::details::MyMcValueTupleReset(::tl2::MyMcValueTuple& item) {
 }
 
 bool tl2::details::MyMcValueTupleWriteJSON(std::ostream& s, const ::tl2::MyMcValueTuple& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"xs\":";
 	if (!::tl2::details::BuiltinTuple3Service1ValueWriteJSON(s, item.xs)) { return false; }
 	s << "}";
@@ -3685,10 +3637,8 @@ void tl2::details::MyMcValueVectorReset(::tl2::MyMcValueVector& item) {
 }
 
 bool tl2::details::MyMcValueVectorWriteJSON(std::ostream& s, const ::tl2::MyMcValueVector& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.xs.size() != 0) {
-		add_comma = true;
 		s << "\"xs\":";
 		if (!::tl2::details::BuiltinVectorService1ValueWriteJSON(s, item.xs)) { return false; }
 	}
@@ -3746,10 +3696,8 @@ void tl2::details::MyStringReset(::tl2::MyString& item) {
 }
 
 bool tl2::details::MyStringWriteJSON(std::ostream& s, const ::tl2::MyString& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.val2.size() != 0) {
-		add_comma = true;
 		s << "\"val2\":";
 		s << "\"" << item.val2 << "\"";
 	}
@@ -4068,10 +4016,8 @@ void tl2::details::RightIntVectorService6FindWithBoundsResultReset(::tl2::Right<
 }
 
 bool tl2::details::RightIntVectorService6FindWithBoundsResultWriteJSON(std::ostream& s, const ::tl2::Right<int32_t, std::vector<::tl2::service6::FindWithBoundsResult>>& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.value.size() != 0) {
-		add_comma = true;
 		s << "\"value\":";
 		if (!::tl2::details::BuiltinVectorService6FindWithBoundsResultWriteJSON(s, item.value)) { return false; }
 	}
@@ -4104,10 +4050,8 @@ void tl2::details::RightService6ErrorVectorService6FindResultRowReset(::tl2::Rig
 }
 
 bool tl2::details::RightService6ErrorVectorService6FindResultRowWriteJSON(std::ostream& s, const ::tl2::Right<::tl2::service6::Error, std::vector<::tl2::service6::FindResultRow>>& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.value.size() != 0) {
-		add_comma = true;
 		s << "\"value\":";
 		if (!::tl2::details::BuiltinVectorService6FindResultRowWriteJSON(s, item.value)) { return false; }
 	}
diff --git a/internal/tlcodegen/test/gen/schema_cpp/antispam/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/antispam/details.cpp
index c94a2182..1cd89422 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/antispam/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/antispam/details.cpp
@@ -34,10 +34,8 @@ void tl2::details::AntispamGetPatternReset(::tl2::antispam::GetPattern& item) {
 }
 
 bool tl2::details::AntispamGetPatternWriteJSON(std::ostream& s, const ::tl2::antispam::GetPattern& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.id != 0) {
-		add_comma = true;
 		s << "\"id\":";
 		s << item.id;
 	}
diff --git a/internal/tlcodegen/test/gen/schema_cpp/pkg2/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/pkg2/details.cpp
index 546ca96b..124c1ac8 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/pkg2/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/pkg2/details.cpp
@@ -33,10 +33,8 @@ void tl2::details::Pkg2FooReset(::tl2::pkg2::Foo& item) {
 }
 
 bool tl2::details::Pkg2FooWriteJSON(std::ostream& s, const ::tl2::pkg2::Foo& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		s << item.x;
 	}
@@ -94,9 +92,7 @@ void tl2::details::Pkg2T1Reset(::tl2::pkg2::T1& item) {
 }
 
 bool tl2::details::Pkg2T1WriteJSON(std::ostream& s, const ::tl2::pkg2::T1& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"x\":";
 	if (!::tl2::details::Pkg2FooWriteJSON(s, item.x)) { return false; }
 	s << "}";
diff --git a/internal/tlcodegen/test/gen/schema_cpp/service1/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/service1/details.cpp
index 8adafceb..adc8d76a 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/service1/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/service1/details.cpp
@@ -1128,10 +1128,8 @@ void tl2::details::Service1DeleteReset(::tl2::service1::Delete& item) {
 }
 
 bool tl2::details::Service1DeleteWriteJSON(std::ostream& s, const ::tl2::service1::Delete& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.key.size() != 0) {
-		add_comma = true;
 		s << "\"key\":";
 		s << "\"" << item.key << "\"";
 	}
@@ -1205,10 +1203,8 @@ void tl2::details::Service1DisableExpirationReset(::tl2::service1::DisableExpira
 }
 
 bool tl2::details::Service1DisableExpirationWriteJSON(std::ostream& s, const ::tl2::service1::DisableExpiration& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.prefix.size() != 0) {
-		add_comma = true;
 		s << "\"prefix\":";
 		s << "\"" << item.prefix << "\"";
 	}
@@ -1282,10 +1278,8 @@ void tl2::details::Service1DisableKeysStatReset(::tl2::service1::DisableKeysStat
 }
 
 bool tl2::details::Service1DisableKeysStatWriteJSON(std::ostream& s, const ::tl2::service1::DisableKeysStat& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.period != 0) {
-		add_comma = true;
 		s << "\"period\":";
 		s << item.period;
 	}
@@ -1359,10 +1353,8 @@ void tl2::details::Service1EnableExpirationReset(::tl2::service1::EnableExpirati
 }
 
 bool tl2::details::Service1EnableExpirationWriteJSON(std::ostream& s, const ::tl2::service1::EnableExpiration& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.prefix.size() != 0) {
-		add_comma = true;
 		s << "\"prefix\":";
 		s << "\"" << item.prefix << "\"";
 	}
@@ -1436,10 +1428,8 @@ void tl2::details::Service1EnableKeysStatReset(::tl2::service1::EnableKeysStat&
 }
 
 bool tl2::details::Service1EnableKeysStatWriteJSON(std::ostream& s, const ::tl2::service1::EnableKeysStat& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.period != 0) {
-		add_comma = true;
 		s << "\"period\":";
 		s << item.period;
 	}
@@ -1513,10 +1503,8 @@ void tl2::details::Service1ExistsReset(::tl2::service1::Exists& item) {
 }
 
 bool tl2::details::Service1ExistsWriteJSON(std::ostream& s, const ::tl2::service1::Exists& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.key.size() != 0) {
-		add_comma = true;
 		s << "\"key\":";
 		s << "\"" << item.key << "\"";
 	}
@@ -1590,10 +1578,8 @@ void tl2::details::Service1GetReset(::tl2::service1::Get& item) {
 }
 
 bool tl2::details::Service1GetWriteJSON(std::ostream& s, const ::tl2::service1::Get& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.key.size() != 0) {
-		add_comma = true;
 		s << "\"key\":";
 		s << "\"" << item.key << "\"";
 	}
@@ -1667,10 +1653,8 @@ void tl2::details::Service1GetExpireTimeReset(::tl2::service1::GetExpireTime& it
 }
 
 bool tl2::details::Service1GetExpireTimeWriteJSON(std::ostream& s, const ::tl2::service1::GetExpireTime& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.key.size() != 0) {
-		add_comma = true;
 		s << "\"key\":";
 		s << "\"" << item.key << "\"";
 	}
@@ -1744,10 +1728,8 @@ void tl2::details::Service1GetKeysStatReset(::tl2::service1::GetKeysStat& item)
 }
 
 bool tl2::details::Service1GetKeysStatWriteJSON(std::ostream& s, const ::tl2::service1::GetKeysStat& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.period != 0) {
-		add_comma = true;
 		s << "\"period\":";
 		s << item.period;
 	}
@@ -1890,10 +1872,8 @@ void tl2::details::Service1GetWildcardReset(::tl2::service1::GetWildcard& item)
 }
 
 bool tl2::details::Service1GetWildcardWriteJSON(std::ostream& s, const ::tl2::service1::GetWildcard& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.prefix.size() != 0) {
-		add_comma = true;
 		s << "\"prefix\":";
 		s << "\"" << item.prefix << "\"";
 	}
@@ -1969,10 +1949,8 @@ void tl2::details::Service1GetWildcardDictReset(::tl2::service1::GetWildcardDict
 }
 
 bool tl2::details::Service1GetWildcardDictWriteJSON(std::ostream& s, const ::tl2::service1::GetWildcardDict& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.prefix.size() != 0) {
-		add_comma = true;
 		s << "\"prefix\":";
 		s << "\"" << item.prefix << "\"";
 	}
@@ -2046,10 +2024,8 @@ void tl2::details::Service1GetWildcardListReset(::tl2::service1::GetWildcardList
 }
 
 bool tl2::details::Service1GetWildcardListWriteJSON(std::ostream& s, const ::tl2::service1::GetWildcardList& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.prefix.size() != 0) {
-		add_comma = true;
 		s << "\"prefix\":";
 		s << "\"" << item.prefix << "\"";
 	}
@@ -2125,10 +2101,8 @@ void tl2::details::Service1GetWildcardWithFlagsReset(::tl2::service1::GetWildcar
 }
 
 bool tl2::details::Service1GetWildcardWithFlagsWriteJSON(std::ostream& s, const ::tl2::service1::GetWildcardWithFlags& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.prefix.size() != 0) {
-		add_comma = true;
 		s << "\"prefix\":";
 		s << "\"" << item.prefix << "\"";
 	}
diff --git a/internal/tlcodegen/test/gen/schema_cpp/service2/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/service2/details.cpp
index d458cb88..55d89f24 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/service2/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/service2/details.cpp
@@ -445,10 +445,8 @@ void tl2::details::Service2ObjectIdReset(::tl2::service2::ObjectId& item) {
 }
 
 bool tl2::details::Service2ObjectIdWriteJSON(std::ostream& s, const ::tl2::service2::ObjectId& item, uint32_t nat_objectIdLength) {
-	auto add_comma = false;
 	s << "{";
 	if ((item.id.size() != 0) || (nat_objectIdLength != 0)) {
-		add_comma = true;
 		s << "\"id\":";
 		if (!::tl2::details::BuiltinTupleIntWriteJSON(s, item.id, nat_objectIdLength)) { return false; }
 	}
diff --git a/internal/tlcodegen/test/gen/schema_cpp/service3/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/service3/details.cpp
index a832c7c0..013f3c4f 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/service3/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/service3/details.cpp
@@ -794,10 +794,8 @@ void tl2::details::Service3GetLastVisitTimestampReset(::tl2::service3::GetLastVi
 }
 
 bool tl2::details::Service3GetLastVisitTimestampWriteJSON(std::ostream& s, const ::tl2::service3::GetLastVisitTimestamp& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.user_id != 0) {
-		add_comma = true;
 		s << "\"user_id\":";
 		s << item.user_id;
 	}
@@ -2259,9 +2257,7 @@ void tl2::details::Service3SetLimitsReset(::tl2::service3::SetLimits& item) {
 }
 
 bool tl2::details::Service3SetLimitsWriteJSON(std::ostream& s, const ::tl2::service3::SetLimits& item) {
-	auto add_comma = false;
 	s << "{";
-	add_comma = true;
 	s << "\"limits\":";
 	if (!::tl2::details::Service3LimitsWriteJSON(s, item.limits)) { return false; }
 	s << "}";
@@ -2424,7 +2420,7 @@ bool tl2::details::VectorService3Product0MaybeWriteJSON(std::ostream & s, const
 	s << "{";
 	if (item) {
 		s << "\"ok\":true";
-		if(*item.size() != 0) {
+		if((*item).size() != 0) {
 			s << ",\"value\":";
 			if (!::tl2::details::BuiltinVectorService3Product0WriteJSON(s, *item)) { return false; }
 		}
@@ -2458,7 +2454,7 @@ bool tl2::details::VectorService3ProductMaybeWriteJSON(std::ostream & s, const s
 	s << "{";
 	if (item) {
 		s << "\"ok\":true";
-		if(*item.size() != 0) {
+		if((*item).size() != 0) {
 			s << ",\"value\":";
 			if (!::tl2::details::BuiltinVectorService3ProductWriteJSON(s, *item, nat_t)) { return false; }
 		}
@@ -2521,7 +2517,7 @@ bool tl2::details::VectorService3ProductStatsOldMaybeWriteJSON(std::ostream & s,
 	s << "{";
 	if (item) {
 		s << "\"ok\":true";
-		if(*item.size() != 0) {
+		if((*item).size() != 0) {
 			s << ",\"value\":";
 			if (!::tl2::details::BuiltinVectorService3ProductStatsOldWriteJSON(s, *item)) { return false; }
 		}
diff --git a/internal/tlcodegen/test/gen/schema_cpp/service5/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/service5/details.cpp
index f37c0356..d5b5b253 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/service5/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/service5/details.cpp
@@ -338,10 +338,8 @@ void tl2::details::Service5PerformQueryReset(::tl2::service5::PerformQuery& item
 }
 
 bool tl2::details::Service5PerformQueryWriteJSON(std::ostream& s, const ::tl2::service5::PerformQuery& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.query.size() != 0) {
-		add_comma = true;
 		s << "\"query\":";
 		s << "\"" << item.query << "\"";
 	}
diff --git a/internal/tlcodegen/test/gen/schema_cpp/service6/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/service6/details.cpp
index 84e2e123..e9ebd764 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/service6/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/service6/details.cpp
@@ -111,10 +111,8 @@ void tl2::details::Service6ErrorReset(::tl2::service6::Error& item) {
 }
 
 bool tl2::details::Service6ErrorWriteJSON(std::ostream& s, const ::tl2::service6::Error& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.code != 0) {
-		add_comma = true;
 		s << "\"code\":";
 		s << item.code;
 	}
@@ -172,10 +170,8 @@ void tl2::details::Service6FindResultRowReset(::tl2::service6::FindResultRow& it
 }
 
 bool tl2::details::Service6FindResultRowWriteJSON(std::ostream& s, const ::tl2::service6::FindResultRow& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		s << item.x;
 	}
@@ -233,10 +229,8 @@ void tl2::details::Service6FindWithBoundsResultReset(::tl2::service6::FindWithBo
 }
 
 bool tl2::details::Service6FindWithBoundsResultWriteJSON(std::ostream& s, const ::tl2::service6::FindWithBoundsResult& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.x != 0) {
-		add_comma = true;
 		s << "\"x\":";
 		s << item.x;
 	}
@@ -395,10 +389,8 @@ void tl2::details::Service6MultiFindWithBoundsReset(::tl2::service6::MultiFindWi
 }
 
 bool tl2::details::Service6MultiFindWithBoundsWriteJSON(std::ostream& s, const ::tl2::service6::MultiFindWithBounds& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.clusters.size() != 0) {
-		add_comma = true;
 		s << "\"clusters\":";
 		if (!::tl2::details::BuiltinVectorIntWriteJSON(s, item.clusters)) { return false; }
 	}
diff --git a/internal/tlcodegen/test/gen/schema_cpp/tree_stats/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/tree_stats/details.cpp
index 6eb693ff..99749f47 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/tree_stats/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/tree_stats/details.cpp
@@ -35,11 +35,11 @@ bool tl2::details::TreeStatsObjectLimitValueWriteJSON(std::ostream & s, const ::
 	s << "\"type\":";
 	s << "\"" << TreeStatsObjectLimitValue_tbl_tl_name[item.value.index()] << "\"";
 	switch (item.value.index()) {
-	if (std::get<1>(item.value) != 0) {
 	case 1:
-		s << ",\"value\":";
-		if (!::tl2::details::TreeStatsObjectLimitValueDoubleWriteJSON(s, std::get<1>(item.value))) { return false; }
-	}
+		if (std::get<1>(item.value) != 0) {
+			s << ",\"value\":";
+			if (!::tl2::details::TreeStatsObjectLimitValueDoubleWriteJSON(s, std::get<1>(item.value))) { return false; }
+		}
 		break;
 	}
 	s << "}";
diff --git a/internal/tlcodegen/test/gen/schema_cpp/unique/details.cpp b/internal/tlcodegen/test/gen/schema_cpp/unique/details.cpp
index cde36784..ec8aad80 100644
--- a/internal/tlcodegen/test/gen/schema_cpp/unique/details.cpp
+++ b/internal/tlcodegen/test/gen/schema_cpp/unique/details.cpp
@@ -33,10 +33,8 @@ void tl2::details::UniqueGetReset(::tl2::unique::Get& item) {
 }
 
 bool tl2::details::UniqueGetWriteJSON(std::ostream& s, const ::tl2::unique::Get& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.key.size() != 0) {
-		add_comma = true;
 		s << "\"key\":";
 		s << "\"" << item.key << "\"";
 	}
@@ -110,10 +108,8 @@ void tl2::details::UniqueStringToIntReset(::tl2::unique::StringToInt& item) {
 }
 
 bool tl2::details::UniqueStringToIntWriteJSON(std::ostream& s, const ::tl2::unique::StringToInt& item) {
-	auto add_comma = false;
 	s << "{";
 	if (item.key.size() != 0) {
-		add_comma = true;
 		s << "\"key\":";
 		s << "\"" << item.key << "\"";
 	}
diff --git a/internal/tlcodegen/type_rw_union_cpp.go b/internal/tlcodegen/type_rw_union_cpp.go
index 401b7149..54e5bddb 100644
--- a/internal/tlcodegen/type_rw_union_cpp.go
+++ b/internal/tlcodegen/type_rw_union_cpp.go
@@ -476,21 +476,25 @@ func (trw *TypeRWUnion) CPPWriteJSONFields(bytesVersion bool) string {
 `, trw.wr.goGlobalName))
 
 		for fieldIndex, field := range trw.Fields {
+			indent := 1
 			if !field.t.IsTrueType() {
+				s.WriteString(fmt.Sprintf("%scase %d:\n", strings.Repeat("\t", indent), fieldIndex))
+				indent++
 				emptyCondition := field.t.trw.CPPTypeJSONEmptyCondition(bytesVersion, fmt.Sprintf("std::get<%d>(item.value)", fieldIndex), field.recursive, nil)
 				if emptyCondition != "" {
-					s.WriteString(fmt.Sprintf("\tif (%s) {\n", emptyCondition))
+					s.WriteString(fmt.Sprintf("%sif (%s) {\n", strings.Repeat("\t", indent), emptyCondition))
+					indent++
 				}
-				s.WriteString(fmt.Sprintf("\tcase %d:\n", fieldIndex))
-				s.WriteString(`		s << ",\"value\":";
-`)
-				s.WriteString("\t" +
+				s.WriteString(fmt.Sprintf(`%ss << ",\"value\":";
+`, strings.Repeat("\t", indent)))
+				s.WriteString(strings.Repeat("\t", indent-1) +
 					field.t.trw.CPPTypeWritingJsonCode(bytesVersion, addAsterisk(field.recursive, fmt.Sprintf("std::get<%d>(item.value)", fieldIndex)),
 						true, formatNatArgsCPP(trw.Fields, field.natArgs), false) + "\n")
 				if emptyCondition != "" {
-					s.WriteString(fmt.Sprintf("\t}\n"))
+					indent--
+					s.WriteString(fmt.Sprintf("%s}\n", strings.Repeat("\t", indent)))
 				}
-				s.WriteString("\t\tbreak;\n")
+				s.WriteString(fmt.Sprintf("%sbreak;\n", strings.Repeat("\t", indent)))
 			}
 		}
 		s.WriteString(`	}