CHECK_C_SOURCE_COMPILES("#define LIBICAL_GLIB_UNSTABLE_API 1
			#include <libical-glib/libical-glib.h>
			int main(void) {
				i_cal_recurrence_get_by (NULL, I_CAL_BY_MONTH, 0);
				return 0;
			}" HAVE_I_CAL_RECURRENCE_GET_BY)