[serialize] Extract iterable copy, copy_all

src/hb-ot-cmap-table.hh

@@ -941,9 +941,9 @@ struct CmapSubtableFormat14
     if (unlikely (!c->extend_min (*this))) return;
     this->format = 14;
 
-    const CmapSubtableFormat14 *src_tbl = reinterpret_cast<const CmapSubtableFormat14*> (src_base);
-    for (const VariationSelectorRecord& _ : src_tbl->record)
-      c->copy (_, unicodes, glyphs, glyph_map, src_base, this);
+    auto src_tbl = reinterpret_cast<const CmapSubtableFormat14*> (src_base);
+    c->copy_all (hb_iter (src_tbl->record),
+		 unicodes, glyphs, glyph_map, src_base, this);
 
     if (c->length () - table_initpos == CmapSubtableFormat14::min_size)
       c->revert (snap);

src/hb-ot-layout-gpos-table.hh

@@ -544,8 +544,7 @@ struct SinglePosFormat1
     if (unlikely (!c->extend_min (*this))) return;
     if (unlikely (!c->check_assign (valueFormat, valFormat))) return;
 
-    for (const auto &_ : hb_second (*it))
-      c->copy (_);
+    c->copy_all (hb_second (*it));
 
     auto glyphs =
     + it
@@ -632,9 +631,7 @@ struct SinglePosFormat2
     if (unlikely (!c->check_assign (valueFormat, valFormat))) return;
     if (unlikely (!c->check_assign (valueCount, it.len ()))) return;
 
-    for (const auto iter : it)
-      for (const auto &_ : iter.second)
-	c->copy (_);
+    for (auto iter : it) c->copy_all (iter.second);
 
     auto glyphs =
     + it

src/hb-ot-name-table.hh

@@ -191,7 +191,7 @@ struct name
 
     const void *dst_string_pool = &(this + this->stringOffset);
 
-    for (const auto &_ : it) c->copy (_, src_string_pool, dst_string_pool);
+    c->copy_all (it, src_string_pool, dst_string_pool);
 
     if (unlikely (c->ran_out_of_room)) return_trace (false);
 

src/hb-ot-vorg-table.hh

@@ -84,7 +84,7 @@ struct VORG
     this->defaultVertOriginY = defaultVertOriginY;
     this->vertYOrigins.len = it.len ();
 
-    for (const auto _ : it) c->copy (_);
+    c->copy_all (it);
   }
 
   bool subset (hb_subset_context_t *c) const

src/hb-serialize.hh

@@ -387,6 +387,12 @@ struct hb_serialize_context_t
   Type *copy (const Type *src, Ts&&... ds)
   { return copy (*src, hb_forward<Ts> (ds)...); }
 
+  template<typename Iterator,
+	   hb_requires (hb_is_iterator (Iterator)),
+	   typename ...Ts>
+  void copy_all (Iterator it, Ts&&... ds)
+  { for (decltype (*it) _ : it) copy (_, hb_forward<Ts> (ds)...); }
+
   template <typename Type>
   hb_serialize_context_t& operator << (const Type &obj) & { embed (obj); return *this; }