#include #include #include "config.h" /** * container_of - routine for upcasting * * It is often convenient to create code where the caller registers a pointer * to a generic structure and a callback. The callback might know that the * pointer points to within a larger structure, and container_of gives a * convenient and fairly type-safe way of returning to the enclosing structure. * * This idiom is an alternative to providing a void * pointer for every * callback. * * Example: * #include * #include * * struct timer { * void *members; * }; * * struct info { * int my_stuff; * struct timer timer; * }; * * static void register_timer(struct timer *timer) * { * //... * } * * static void my_timer_callback(struct timer *timer) * { * struct info *info = container_of(timer, struct info, timer); * printf("my_stuff is %u\n", info->my_stuff); * } * * int main(void) * { * struct info info = { .my_stuff = 1 }; * * register_timer(&info.timer); * // ... * return 0; * } * * License: CC0 (Public domain) * Author: Rusty Russell */ int main(int argc, char *argv[]) { if (argc != 2) return 1; if (strcmp(argv[1], "depends") == 0) { printf("ccan/check_type\n"); return 0; } return 1; }