From 589986012c4b3ab68e299a2eadca18f90080113b Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 14 Jul 2022 20:28:04 +0200 Subject: Merging upstream version 2.0. Signed-off-by: Daniel Baumann --- ccan/ccan/container_of/_info | 65 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 ccan/ccan/container_of/_info (limited to 'ccan/ccan/container_of/_info') diff --git a/ccan/ccan/container_of/_info b/ccan/ccan/container_of/_info new file mode 100644 index 0000000..b116052 --- /dev/null +++ b/ccan/ccan/container_of/_info @@ -0,0 +1,65 @@ +#include "config.h" +#include +#include + +/** + * 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 my_timer_callback(struct timer *timer) + * { + * struct info *info = container_of(timer, struct info, timer); + * printf("my_stuff is %u\n", info->my_stuff); + * } + * + * static void register_timer(struct timer *timer) + * { + * (void)timer; + * (void)my_timer_callback; + * //... + * } + * + * 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; +} -- cgit v1.2.3