Adapted snippet from the Linux source code demonstrating the use of GCC statement expressions to implement intrusive linked lists in C.

container_of.c

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

#define container_of(type, ptr, member) \
({ \
	size_t offset = (size_t)&(((type *)0)->member); \
	char *start_addr = (char *)(ptr) - offset; \
	(type *)start_addr; \
})

struct list {
	struct list *prev;
	struct list *next;
};

struct device {
	int id;
	struct list list;
};

struct device *new_device(int id) {
	struct device *dev = (struct device *)malloc(sizeof(struct device));
	if (dev == NULL) {
		fprintf(stderr, "failed to allocate memory");
		exit(EXIT_FAILURE);
	}
	dev->id = id;
	dev->list.prev = NULL;
	dev->list.next = NULL;
	return dev;
}

int main() {
	struct device *head = new_device(1);
	struct device *ptr = container_of(struct device, &(head->list), list);
	printf("addresses: %p %p\n", head, ptr);
	free(head);
	head = NULL;
	ptr = NULL;
	return 0;
}