Add set/hashmap helpers for non-trivial freeing and use where straighforward

A macro is needed because otherwise we couldn't ensure type safety.
Some simple tests are included.
No functional change intended.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/basic/set.h b/src/basic/set.h
index 08b7c4a72..b424f3423 100644
--- a/src/basic/set.h
+++ b/src/basic/set.h
@@ -109,6 +109,18 @@ static inline void *set_steal_first(Set *s) {
         return internal_hashmap_steal_first(HASHMAP_BASE(s));
 }
 
+#define set_clear_with_destructor(_s, _f)               \
+        ({                                              \
+                void *_item;                            \
+                while ((_item = set_steal_first(_s)))   \
+                        _f(_item);                      \
+        })
+#define set_free_with_destructor(_s, _f)                \
+        ({                                              \
+                set_clear_with_destructor(_s, _f);      \
+                set_free(_s);                           \
+        })
+
 /* no set_steal_first_key */
 /* no set_first_key */