Minor

src/hb-ot-map.hh

diff --git a/src/hb-ot-map.hh b/src/hb-ot-map.hh
index 16a0c47..40b9921 100644
--- a/src/hb-ot-map.hh
+++ b/src/hb-ot-map.hh
@@ -205,8 +205,10 @@
   inline void add_feature (const hb_ot_map_feature_t &feat)
   { add_feature (feat.tag, feat.flags); }
 
-  inline void enable_feature (hb_tag_t tag)
-  { add_feature (tag, F_GLOBAL); }
+  inline void enable_feature (hb_tag_t tag,
+			      hb_ot_map_feature_flags_t flags=F_NONE,
+			      unsigned int value=1)
+  { add_feature (tag, F_GLOBAL | flags, value); }
 
   inline void disable_feature (hb_tag_t tag)
   { add_feature (tag, F_GLOBAL, 0); }

src/hb-ot-shape-complex-arabic.cc

diff --git a/src/hb-ot-shape-complex-arabic.cc b/src/hb-ot-shape-complex-arabic.cc
index 9893a22..2cdd7ba 100644
--- a/src/hb-ot-shape-complex-arabic.cc
+++ b/src/hb-ot-shape-complex-arabic.cc
@@ -215,14 +215,14 @@
    * however, it says a ZWJ should also mean "don't ligate".  So we run
    * the main ligating features as MANUAL_ZWJ. */
 
-  map->add_feature (HB_TAG('r','l','i','g'), F_GLOBAL | F_MANUAL_ZWJ | F_HAS_FALLBACK);
+  map->enable_feature (HB_TAG('r','l','i','g'), F_MANUAL_ZWJ | F_HAS_FALLBACK);
 
   if (plan->props.script == HB_SCRIPT_ARABIC)
     map->add_gsub_pause (arabic_fallback_shape);
 
   /* No pause after rclt.  See 98460779bae19e4d64d29461ff154b3527bf8420. */
-  map->add_feature (HB_TAG('r','c','l','t'), F_GLOBAL | F_MANUAL_ZWJ);
-  map->add_feature (HB_TAG('c','a','l','t'), F_GLOBAL | F_MANUAL_ZWJ);
+  map->enable_feature (HB_TAG('r','c','l','t'), F_MANUAL_ZWJ);
+  map->enable_feature (HB_TAG('c','a','l','t'), F_MANUAL_ZWJ);
   map->add_gsub_pause (nullptr);
 
   /* And undo here. */

src/hb-ot-shape-complex-myanmar.cc

diff --git a/src/hb-ot-shape-complex-myanmar.cc b/src/hb-ot-shape-complex-myanmar.cc
index b0ca3c7..bebb8ec 100644
--- a/src/hb-ot-shape-complex-myanmar.cc
+++ b/src/hb-ot-shape-complex-myanmar.cc
@@ -106,14 +106,14 @@
 
   for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
   {
-    map->add_feature (basic_features[i], F_GLOBAL | F_MANUAL_ZWJ);
+    map->enable_feature (basic_features[i], F_MANUAL_ZWJ);
     map->add_gsub_pause (nullptr);
   }
 
   map->add_gsub_pause (final_reordering);
 
   for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
-    map->add_feature (other_features[i], F_GLOBAL | F_MANUAL_ZWJ);
+    map->enable_feature (other_features[i], F_MANUAL_ZWJ);
 
   for (unsigned int i = 0; i < ARRAY_LENGTH (positioning_features); i++)
     map->enable_feature (positioning_features[i]);

src/hb-ot-shape-complex-use.cc

diff --git a/src/hb-ot-shape-complex-use.cc b/src/hb-ot-shape-complex-use.cc
index bdcad40..f9a580c 100644
--- a/src/hb-ot-shape-complex-use.cc
+++ b/src/hb-ot-shape-complex-use.cc
@@ -132,19 +132,19 @@
   map->enable_feature (HB_TAG('l','o','c','l'));
   map->enable_feature (HB_TAG('c','c','m','p'));
   map->enable_feature (HB_TAG('n','u','k','t'));
-  map->add_feature (HB_TAG('a','k','h','n'), F_GLOBAL | F_MANUAL_ZWJ);
+  map->enable_feature (HB_TAG('a','k','h','n'), F_MANUAL_ZWJ);
 
   /* "Reordering group" */
   map->add_gsub_pause (clear_substitution_flags);
   map->add_feature (HB_TAG('r','p','h','f'), F_MANUAL_ZWJ);
   map->add_gsub_pause (record_rphf);
   map->add_gsub_pause (clear_substitution_flags);
-  map->add_feature (HB_TAG('p','r','e','f'), F_GLOBAL | F_MANUAL_ZWJ);
+  map->enable_feature (HB_TAG('p','r','e','f'), F_MANUAL_ZWJ);
   map->add_gsub_pause (record_pref);
 
   /* "Orthographic unit shaping group" */
   for (unsigned int i = 0; i < ARRAY_LENGTH (basic_features); i++)
-    map->add_feature (basic_features[i], F_GLOBAL | F_MANUAL_ZWJ);
+    map->enable_feature (basic_features[i], F_MANUAL_ZWJ);
 
   map->add_gsub_pause (reorder);
 
@@ -155,7 +155,7 @@
 
   /* "Standard typographic presentation" */
   for (unsigned int i = 0; i < ARRAY_LENGTH (other_features); i++)
-    map->add_feature (other_features[i], F_GLOBAL | F_MANUAL_ZWJ);
+    map->enable_feature (other_features[i], F_MANUAL_ZWJ);
 
   /* "Positional feature application" */
   for (unsigned int i = 0; i < ARRAY_LENGTH (positioning_features); i++)

src/hb-ot-shape.cc

diff --git a/src/hb-ot-shape.cc b/src/hb-ot-shape.cc
index 34434ef..dc88fa9 100644
--- a/src/hb-ot-shape.cc
+++ b/src/hb-ot-shape.cc
@@ -125,7 +125,7 @@
   map->add_feature (HB_TAG ('d','n','o','m'));
 
   /* Random! */
-  map->add_feature (HB_TAG ('r','a','n','d'), F_GLOBAL | F_RANDOM, HB_OT_MAP_MAX_VALUE);
+  map->enable_feature (HB_TAG ('r','a','n','d'), F_RANDOM, HB_OT_MAP_MAX_VALUE);
 
   if (planner->shaper->collect_features)
     planner->shaper->collect_features (planner);
@@ -142,7 +142,7 @@
      * matter which script/langsys it is listed (or not) under.
      * See various bugs referenced from:
      * https://github.com/harfbuzz/harfbuzz/issues/63 */
-    map->add_feature (HB_TAG ('v','e','r','t'), F_GLOBAL | F_GLOBAL_SEARCH);
+    map->enable_feature (HB_TAG ('v','e','r','t'), F_GLOBAL_SEARCH);
   }
 
   if (planner->shaper->override_features)