experimental object creation and validation in C

person.c

#include <stdlib.h>
#include <stdio.h>

#define PERSON_NAME_UNSET   0x0001
#define PERSON_GROUPS_UNSET 0x0002

typedef struct collection_t {
	void **items;
	int count;
	int available;
} collection_t;

typedef struct person_t {
	char *name;
	int birthday;

	int _errors;
	collection_t *groups;
} person_t;

int
person_validate(person_t *person)
{
	person->_errors = 0;

	if (person->name == NULL) {
		person->_errors |= PERSON_NAME_UNSET;
	}

	if (person->groups == NULL) {
		person->_errors |= PERSON_GROUPS_UNSET;
	}

	return person->_errors == 0;
}

int
main(int agrc, char **argv)
{
	person_t *person = malloc(sizeof (person_t *));


	if (person_validate(person)) {
		printf("%s is a valid person object!\n", person->name);
	} else {
		if (person->_errors & PERSON_NAME_UNSET) {
			person->name = "";
		}

		if (person->_errors & PERSON_GROUPS_UNSET) {
			person->groups = (collection_t *)malloc(sizeof (collection_t *));
		}

		if (person_validate(person)) {
			puts("Validation passed with defaults!");
		} else {
			puts("Validation failed with defaults!");
		}
	}

	return EXIT_SUCCESS;
}