: optional<std::string>(i->second);
}
// Remove a surface id and name
// I don't think I will need this, do I?
void remove_id(std::string const &name) {
: optional<std::string>(i->second);
}
// Remove a surface id and name
// I don't think I will need this, do I?
void remove_id(std::string const &name) {