--- a/src/StreamRelationalWriter.h	Sun Jul 22 00:08:13 2018 +0200
+++ b/src/StreamRelationalWriter.h	Sun Jul 22 10:26:22 2018 +0200
@@ -23,20 +23,20 @@
 	types::IntegerDataTypeWriter integerWriter;
 	types::StringDataTypeWriter stringWriter;
 	vector<DataTypeWriterBase*> writers = {&booleanWriter, &integerWriter, &stringWriter};
-	
+
 	/**
 	 * count of columns in the current table
 	 */
 	integer_t columnCount;
-	
+
 	/**
 	 * types of columns in the current table
 	 */
-	vector<integer_t> columnTypes;
+	vector<TypeId> columnTypes;
 
-	void writeString(const string_t &stringValue, const integer_t typeId) {
+	void writeString(const string_t &stringValue, const TypeId typeId) {
 		for (DataTypeWriterBase* writer : writers) if (writer->supports(typeId)) return writer->writeString(output, stringValue);
-		throw RelpipeWriterException(L"Unsupported data type: " + typeId);
+		throw RelpipeWriterException(L"Unsupported data type: " + static_cast<integer_t>(typeId));
 	}
 
 public:
@@ -45,16 +45,16 @@
 	output(output) {
 	}
 
-	integer_t toTypeId(const string_t typeCode) override {
+	TypeId toTypeId(const string_t typeCode) override {
 		for (DataTypeWriterBase* writer : writers) if (writer->supports(typeCode)) return writer->getTypeId();
 		throw RelpipeWriterException(L"Unsupported data type: " + typeCode);
 	}
 
-	string_t toTypeCode(const integer_t typeId) override {
+	string_t toTypeCode(const TypeId typeId) override {
 		for (DataTypeWriterBase* writer : writers) if (writer->supports(typeId)) return writer->getTypeCode();
-		throw RelpipeWriterException(L"Unsupported data type: " + typeId);
+		throw RelpipeWriterException(L"Unsupported data type: " + static_cast<integer_t>(typeId));
 	}
-
+	
 	void startRelation(string_t name, std::vector<std::pair<string_t, TypeId> > attributes, boolean_t writeHeader) override {
 		string_t tableName = name;
 		columnCount = attributes.size();
@@ -69,14 +69,14 @@
 
 		// Write column names:
 		for (size_t c = 0; c < columnCount; c++) {
-			wstring columnName = attributes[c].first;			
+			wstring columnName = attributes[c].first;
 			stringWriter.writeValue(output, columnName);
 		}
 
 		// Write column types:
 		for (size_t c = 0; c < columnCount; c++) {
-			integer_t typeId = static_cast<integer_t>(attributes[c].second);
-			integerWriter.writeValue(output, typeId);
+			TypeId typeId = attributes[c].second;
+			integerWriter.writeValue(output, static_cast<integer_t>(typeId));
 			columnTypes[c] = typeId;
 		}
 
@@ -91,7 +91,7 @@
 			}
 
 			wstring stringValue = attributes[c];
-			integer_t typeId = columnTypes[c % columnCount];
+			TypeId typeId = columnTypes[c % columnCount];
 			writeString(stringValue, typeId);
 		}
 	}