ruby-duckdb.h in duckdb-0.0.10

- old
+ new

@@ -8,7 +8,10 @@
 #include "./connection.h"
 #include "./result.h"
 #include "./prepared_statement.h"
 
 extern VALUE mDuckDB;
+extern VALUE cDuckDBDatabase;
+extern VALUE cDuckDBConnection;
+extern VALUE eDuckDBError;
 
 #endif