diff --git a/src/OT/Layout/Common/CoverageFormat1.hh b/src/OT/Layout/Common/CoverageFormat1.hh
index 5d68e3d15..3f598d40e 100644
--- a/src/OT/Layout/Common/CoverageFormat1.hh
+++ b/src/OT/Layout/Common/CoverageFormat1.hh
@@ -79,7 +79,7 @@ struct CoverageFormat1_3
   {
     if (glyphArray.len > glyphs->get_population () * hb_bit_storage ((unsigned) glyphArray.len) / 2)
     {
-      for (hb_codepoint_t g = HB_SET_VALUE_INVALID; glyphs->next (&g);)
+      for (auto g : *glyphs)
         if (get_coverage (g) != NOT_COVERED)
 	  return true;
       return false;
diff --git a/src/OT/Layout/Common/CoverageFormat2.hh b/src/OT/Layout/Common/CoverageFormat2.hh
index fa501d659..9c8754235 100644
--- a/src/OT/Layout/Common/CoverageFormat2.hh
+++ b/src/OT/Layout/Common/CoverageFormat2.hh
@@ -122,7 +122,7 @@ struct CoverageFormat2_4
   {
     if (rangeRecord.len > glyphs->get_population () * hb_bit_storage ((unsigned) rangeRecord.len) / 2)
     {
-      for (hb_codepoint_t g = HB_SET_VALUE_INVALID; glyphs->next (&g);)
+      for (auto g : *glyphs)
         if (get_coverage (g) != NOT_COVERED)
 	  return true;
       return false;
diff --git a/src/graph/graph.hh b/src/graph/graph.hh
index 73f897d2f..0ad4e2ced 100644
--- a/src/graph/graph.hh
+++ b/src/graph/graph.hh
@@ -733,8 +733,7 @@ struct graph_t
     remap_obj_indices (index_map, parents.iter (), true);
 
     // Update roots set with new indices as needed.
-    uint32_t next = HB_SET_VALUE_INVALID;
-    while (roots.next (&next))
+    for (auto next : roots)
     {
       const uint32_t *v;
       if (index_map.has (next, &v))
diff --git a/src/hb-bimap.hh b/src/hb-bimap.hh
index 9edefd971..2e1af30d0 100644
--- a/src/hb-bimap.hh
+++ b/src/hb-bimap.hh
@@ -122,8 +122,7 @@ struct hb_inc_bimap_t : hb_bimap_t
 
   void add_set (const hb_set_t *set)
   {
-    hb_codepoint_t i = HB_SET_VALUE_INVALID;
-    while (hb_set_next (set, &i)) add (i);
+    for (auto i : *set) add (i);
   }
 
   /* Create an identity map. */
diff --git a/src/hb-ot-cmap-table.hh b/src/hb-ot-cmap-table.hh
index 5fef305d8..07db3fbd5 100644
--- a/src/hb-ot-cmap-table.hh
+++ b/src/hb-ot-cmap-table.hh
@@ -937,8 +937,7 @@ struct DefaultUVS : SortedArray32Of<UnicodeValueRange>
       hb_codepoint_t start = HB_SET_VALUE_INVALID;
       hb_codepoint_t end = HB_SET_VALUE_INVALID;
 
-      for (hb_codepoint_t u = HB_SET_VALUE_INVALID;
-	   unicodes->next (&u);)
+      for (auto u : *unicodes)
       {
         if (!as_array ().bsearch (u))
 	  continue;
diff --git a/src/hb-ot-layout-common.hh b/src/hb-ot-layout-common.hh
index 9041198e2..cf344dcf4 100644
--- a/src/hb-ot-layout-common.hh
+++ b/src/hb-ot-layout-common.hh
@@ -1919,7 +1919,7 @@ struct ClassDefFormat2_4
   {
     if (rangeRecord.len > glyphs->get_population () * hb_bit_storage ((unsigned) rangeRecord.len) / 2)
     {
-      for (hb_codepoint_t g = HB_SET_VALUE_INVALID; glyphs->next (&g);)
+      for (auto g : *glyphs)
         if (get_class (g))
 	  return true;
       return false;
@@ -1979,8 +1979,7 @@ struct ClassDefFormat2_4
     unsigned count = rangeRecord.len;
     if (count > glyphs->get_population () * hb_bit_storage (count) * 8)
     {
-      for (hb_codepoint_t g = HB_SET_VALUE_INVALID;
-	   glyphs->next (&g);)
+      for (auto g : *glyphs)
       {
         unsigned i;
         if (rangeRecord.as_array ().bfind (g, &i) &&
diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index cbc694ef9..c40ca08ab 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -1316,8 +1316,7 @@ hb_ot_layout_collect_lookups (hb_face_t      *face,
   hb_set_t feature_indexes;
   hb_ot_layout_collect_features (face, table_tag, scripts, languages, features, &feature_indexes);
 
-  for (hb_codepoint_t feature_index = HB_SET_VALUE_INVALID;
-       hb_set_next (&feature_indexes, &feature_index);)
+  for (auto feature_index : feature_indexes)
     g.get_feature (feature_index).add_lookup_indexes_to (lookup_indexes);
 
   g.feature_variation_collect_lookups (&feature_indexes, nullptr, lookup_indexes);
@@ -1570,7 +1569,7 @@ hb_ot_layout_lookups_substitute_closure (hb_face_t      *face,
     glyphs_length = glyphs->get_population ();
     if (lookups)
     {
-      for (hb_codepoint_t lookup_index = HB_SET_VALUE_INVALID; hb_set_next (lookups, &lookup_index);)
+      for (auto lookup_index : *lookups)
 	gsub.get_lookup (lookup_index).closure (&c, lookup_index);
     }
     else
diff --git a/src/hb-ot-os2-table.hh b/src/hb-ot-os2-table.hh
index 6c776170c..72cb66247 100644
--- a/src/hb-ot-os2-table.hh
+++ b/src/hb-ot-os2-table.hh
@@ -287,8 +287,7 @@ struct OS2
     /* This block doesn't show up in profiles. If it ever did,
      * we can rewrite it to iterate over OS/2 ranges and use
      * set iteration to check if the range matches. */
-    for (hb_codepoint_t cp = HB_SET_VALUE_INVALID;
-	 codepoints->next (&cp);)
+    for (auto cp : *codepoints)
     {
       unsigned int bit = _hb_ot_os2_get_unicode_range_bit (cp);
       if (bit < 128)
diff --git a/src/hb-subset-cff-common.hh b/src/hb-subset-cff-common.hh
index 99e89f781..34b9a5e26 100644
--- a/src/hb-subset-cff-common.hh
+++ b/src/hb-subset-cff-common.hh
@@ -607,8 +607,7 @@ struct subr_remap_t : hb_inc_bimap_t
      */
 
     resize (closure->get_population ());
-    hb_codepoint_t old_num = HB_SET_VALUE_INVALID;
-    while (hb_set_next (closure, &old_num))
+    for (auto old_num : *closure)
       add (old_num);
 
     if (get_population () < 1240)
diff --git a/src/test-gsub-get-alternates.cc b/src/test-gsub-get-alternates.cc
index c9f3b4edb..555440c59 100644
--- a/src/test-gsub-get-alternates.cc
+++ b/src/test-gsub-get-alternates.cc
@@ -65,7 +65,7 @@ main (int argc, char **argv)
   for (unsigned i = 0; i < count; i++)
   {
     unsigned alt_count = 0;
-    for (unsigned lookup_index = HB_SET_VALUE_INVALID;
+    for (hb_codepoint_t lookup_index = HB_SET_VALUE_INVALID;
 	 hb_set_next (lookup_indexes, &lookup_index);)
       if ((alt_count = hb_ot_layout_lookup_get_glyph_alternates (face,
 								 lookup_index,