--- /dev/null
+#include <stdlib.h>
+
+#include <ccan/tcon/tcon.h>
+#include <ccan/build_assert/build_assert.h>
+#include <ccan/tap/tap.h>
+
+struct inner {
+ int inner_val;
+};
+
+struct outer {
+ int outer_val;
+ struct inner inner;
+};
+
+struct info_base {
+ char *infop;
+};
+
+struct info_tcon {
+ struct info_base base;
+ TCON(TCON_CONTAINER(concan, struct outer, inner));
+};
+
+int main(int argc, char *argv[])
+{
+ /* Const should work! */
+ const struct outer *ovar;
+ struct outer *o;
+ struct info_tcon info;
+
+ o = tcon_container_of(&info, fi, &ovar->inner);
+ return (o == ovar);
+}
+