[subset-input] Use shared_ptr for sets

src/hb-subset-input.cc

@@ -46,7 +46,7 @@ hb_subset_input_create_or_fail (void)
     return nullptr;
 
   for (auto& set : input->sets_iter ())
-    set = hb_set_create ();
+    set = hb::shared_ptr<hb_set_t> (hb_set_create ());
 
   if (input->in_error ())
   {

src/hb-subset-input.hh

@@ -33,7 +33,7 @@
 #include "hb-subset.h"
 #include "hb-map.hh"
 #include "hb-set.hh"
-
+#include "hb-cplusplus.hh"
 #include "hb-font.hh"
 
 struct hb_ot_name_record_ids_t
@@ -82,11 +82,10 @@ HB_MARK_AS_FLAG_T (hb_subset_flags_t);
 
 struct hb_subset_input_t
 {
+  hb_subset_input_t () {}
+
   ~hb_subset_input_t ()
   {
-    for (hb_set_t* set : sets_iter ())
-      hb_set_destroy (set);
-
 #ifdef HB_EXPERIMENTAL_API
     for (auto _ : name_table_overrides)
       _.second.fini ();
@@ -96,19 +95,19 @@ struct hb_subset_input_t
   hb_object_header_t header;
 
   struct sets_t {
-    hb_set_t *glyphs;
-    hb_set_t *unicodes;
-    hb_set_t *no_subset_tables;
-    hb_set_t *drop_tables;
-    hb_set_t *name_ids;
-    hb_set_t *name_languages;
-    hb_set_t *layout_features;
-    hb_set_t *layout_scripts;
+    hb::shared_ptr<hb_set_t> glyphs;
+    hb::shared_ptr<hb_set_t> unicodes;
+    hb::shared_ptr<hb_set_t> no_subset_tables;
+    hb::shared_ptr<hb_set_t> drop_tables;
+    hb::shared_ptr<hb_set_t> name_ids;
+    hb::shared_ptr<hb_set_t> name_languages;
+    hb::shared_ptr<hb_set_t> layout_features;
+    hb::shared_ptr<hb_set_t> layout_scripts;
   };
 
   union {
     sets_t sets;
-    hb_set_t* set_ptrs[sizeof (sets_t) / sizeof (hb_set_t*)];
+    hb::shared_ptr<hb_set_t> set_ptrs[sizeof (sets_t) / sizeof (hb_set_t*)];
   };
 
   unsigned flags;
@@ -127,9 +126,9 @@ struct hb_subset_input_t
     return sizeof (set_ptrs) / sizeof (hb_set_t*);
   }
 
-  inline hb_array_t<hb_set_t*> sets_iter ()
+  inline hb_array_t<hb::shared_ptr<hb_set_t>> sets_iter ()
   {
-    return hb_array_t<hb_set_t*> (set_ptrs, num_sets ());
+    return hb_array (set_ptrs);
   }
 
   bool in_error () const