C's subtyping demonstration example

subtype.c

#include <stdio.h>

struct Person {
	int age;
};

struct Student {
	int age;
	int score;
};

void print_age(void *p) {
	struct Person person = *((struct Person *)p);

	printf("my age: %d\n", person.age);
}

void print_score(void *p) {
	struct Student student = *((struct Student *)p);

	printf("my score: %d\n", student.score);
}

int main() {
	struct Person p1 = {44};
	struct Student s1 = {16, 90};

	print_age(&p1);
	print_age(&s1);
	
	print_score(&p1);
	print_score(&s1);

	return 0;
}