From 24e314ca2b56f059f8af28a20b0d2215dbe33eaa Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Karel=20Ko=C4=8D=C3=AD?= Date: Sat, 4 Oct 2025 12:47:24 +0200 Subject: Add presentation: 2025-linuxdays --- 2025-linuxdays/priv.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 2025-linuxdays/priv.c (limited to '2025-linuxdays/priv.c') diff --git a/2025-linuxdays/priv.c b/2025-linuxdays/priv.c new file mode 100644 index 0000000..ed3ad1a --- /dev/null +++ b/2025-linuxdays/priv.c @@ -0,0 +1,38 @@ +#include +#include + +struct pub { + void (*print_name)(struct pub *); +}; +typedef struct pub *pub_t; +#define pub_print_name(PUB) (PUB)->print_name(PUB) + +struct priv { + struct pub pub; + const char *name; +}; +void pname_priv(struct pub *pub) { + struct priv *priv = (struct priv *)pub; + printf("%s", priv->name); +} + +struct wrap { + struct pub *subpub; + struct pub pub; +}; +void pname_wrap(struct pub *pub) { + struct wrap *wrap = (void *)pub - offsetof(struct wrap, pub); + printf("Wrap: "); + wrap->subpub->print_name(wrap->subpub); +} + +int main(int argc, char *argv[]) { + struct priv priv = {.pub = {pname_priv}, .name = "FOO"}; + pub_t p = &priv.pub; + pub_print_name(p); + putchar('\n'); + + struct wrap wrap = {.pub = {pname_wrap}, .subpub = &priv.pub}; + wrap.pub.print_name(&wrap.pub); + putchar('\n'); +} -- cgit v1.2.3