#include <stdint.h>
#include <glibmm.h>
#include <boost/shared_ptr.hpp>
+#include <boost/optional.hpp>
#include "types.h"
#include "exceptions.h"
#include "dcp_time.h"
Time time_attribute (std::string);
float float_attribute (std::string);
std::string string_attribute (std::string);
+ std::string optional_string_attribute (std::string);
int64_t int64_attribute (std::string);
int64_t optional_int64_attribute (std::string);
+ boost::optional<bool> optional_bool_attribute (std::string);
+ boost::optional<Color> optional_color_attribute (std::string);
std::string content ();