TIL about arrays in signatures in C

test-array-signature.c

#include <stdlib.h>

int test1(int32_t (*array)[10]) {
	return 1;
}

int test2(int32_t (*array)[5]) {
	return 2;
}

int main(int argc, char **argv) {
	int32_t a1[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
	int32_t a2[5] = {0, 1, 2, 3, 4};

	test1(&a1);
	test1(&a2); // warning: incompatible pointer types passing 'int32_t (*)[5]' to parameter of type 'int32_t (*)[10]'
	test2(&a1); // warning: incompatible pointer types passing 'int32_t (*)[10]' to parameter of type 'int32_t (*)[5]'
	test2(&a2);

	return 0;
}