Function select

tests/boost_optional.cc:19–27

}

void select(database& db, bool should_be_null) {
	db << "select id,val from test" >> [&](long long, boost::optional<int> val) {
		if(should_be_null) {
			if(val) exit(EXIT_FAILURE);
		} else {
			if(!val) exit(EXIT_FAILURE);
		}
	};
}

struct TmpFile {
	string fname;