diff --git a/src/hb-array.hh b/src/hb-array.hh
index 705bc6a46..ae0d16684 100644
--- a/src/hb-array.hh
+++ b/src/hb-array.hh
@@ -319,7 +319,7 @@ bool hb_array_t<T>::operator == (const hb_array_t<T> &o) const
 {
   return length == o.length &&
   + hb_zip (*this, o)
-  | hb_map ([] (hb_pair_t<T&, T&> &&_) -> bool { return _.first == _.second; })
+  | hb_map ([] (hb_pair_t<T&, T&> &&_) { return _.first == _.second; })
   | hb_all
   ;
 }
@@ -329,7 +329,7 @@ uint32_t hb_array_t<T>::hash () const
   return
   + hb_iter (*this)
   | hb_map (hb_hash)
-  | hb_reduce ([] (uint32_t a, uint32_t b) -> uint32_t { return a * 31 + b; }, 0)
+  | hb_reduce ([] (uint32_t a, uint32_t b) { return a * 31 + b; }, 0)
   ;
 }
 
diff --git a/src/hb-ot-layout-gsub-table.hh b/src/hb-ot-layout-gsub-table.hh
index a6e9a7534..6937e8a72 100644
--- a/src/hb-ot-layout-gsub-table.hh
+++ b/src/hb-ot-layout-gsub-table.hh
@@ -48,7 +48,7 @@ struct SingleSubstFormat1
   {
     + hb_iter (this+coverage)
     | hb_filter (*c->glyphs)
-    | hb_map ([&] (hb_codepoint_t g) -> hb_codepoint_t { return (g + deltaGlyphID) & 0xFFFFu; })
+    | hb_map ([&] (hb_codepoint_t g) { return (g + deltaGlyphID) & 0xFFFFu; })
     | hb_sink (c->output)
     ;
   }
@@ -58,7 +58,7 @@ struct SingleSubstFormat1
     if (unlikely (!(this+coverage).add_coverage (c->input))) return;
 
     + hb_iter (this+coverage)
-    | hb_map ([&] (hb_codepoint_t g) -> hb_codepoint_t { return (g + deltaGlyphID) & 0xFFFFu; })
+    | hb_map ([&] (hb_codepoint_t g) { return (g + deltaGlyphID) & 0xFFFFu; })
     | hb_sink (c->output)
     ;
   }
@@ -741,7 +741,7 @@ struct LigatureSet
   {
     return
     + hb_iter (ligature)
-    | hb_map ([&] (const OffsetTo<Ligature> &_) -> bool { return (this+_).intersects (glyphs); })
+    | hb_map ([&] (const OffsetTo<Ligature> &_) { return (this+_).intersects (glyphs); })
     | hb_any
     ;
   }
@@ -764,7 +764,7 @@ struct LigatureSet
   {
     return
     + hb_iter (ligature)
-    | hb_map ([&] (const OffsetTo<Ligature> &_) -> bool { return (this+_).would_apply (c); })
+    | hb_map ([&] (const OffsetTo<Ligature> &_) { return (this+_).would_apply (c); })
     | hb_any
     ;
   }
diff --git a/src/hb-ot-layout-gsubgpos.hh b/src/hb-ot-layout-gsubgpos.hh
index 5946db7c4..a8deb70d4 100644
--- a/src/hb-ot-layout-gsubgpos.hh
+++ b/src/hb-ot-layout-gsubgpos.hh
@@ -708,7 +708,7 @@ static inline bool intersects_array (const hb_set_t *glyphs,
 {
   return
   + hb_iter (values, count)
-  | hb_map ([&] (const HBUINT16 &_) -> bool { return intersects_func (glyphs, _, intersects_data); })
+  | hb_map ([&] (const HBUINT16 &_) { return intersects_func (glyphs, _, intersects_data); })
   | hb_any
   ;
 }
@@ -1371,7 +1371,7 @@ struct RuleSet
   {
     return
     + hb_iter (rule)
-    | hb_map ([&] (const OffsetTo<Rule> &_) -> bool { return (this+_).intersects (glyphs, lookup_context); })
+    | hb_map ([&] (const OffsetTo<Rule> &_) { return (this+_).intersects (glyphs, lookup_context); })
     | hb_any
     ;
   }
@@ -1399,7 +1399,7 @@ struct RuleSet
   {
     return
     + hb_iter (rule)
-    | hb_map ([&] (const OffsetTo<Rule> &_) -> bool { return (this+_).would_apply (c, lookup_context); })
+    | hb_map ([&] (const OffsetTo<Rule> &_) { return (this+_).would_apply (c, lookup_context); })
     | hb_any
     ;
   }
@@ -1410,7 +1410,7 @@ struct RuleSet
     TRACE_APPLY (this);
     return_trace (
     + hb_iter (rule)
-    | hb_map ([&] (const OffsetTo<Rule> &_) -> bool { return (this+_).apply (c, lookup_context); })
+    | hb_map ([&] (const OffsetTo<Rule> &_) { return (this+_).apply (c, lookup_context); })
     | hb_any
     )
     ;
@@ -1444,7 +1444,7 @@ struct ContextFormat1
     + hb_zip (this+coverage, ruleSet)
     | hb_filter (*glyphs, hb_first)
     | hb_map (hb_second)
-    | hb_map ([&] (const OffsetTo<RuleSet> &_) -> bool { return (this+_).intersects (glyphs, lookup_context); })
+    | hb_map ([&] (const OffsetTo<RuleSet> &_) { return (this+_).intersects (glyphs, lookup_context); })
     | hb_any
     ;
   }
@@ -2022,7 +2022,7 @@ struct ChainRuleSet
   {
     return
     + hb_iter (rule)
-    | hb_map ([&] (const OffsetTo<ChainRule> &_) -> bool { return (this+_).intersects (glyphs, lookup_context); })
+    | hb_map ([&] (const OffsetTo<ChainRule> &_) { return (this+_).intersects (glyphs, lookup_context); })
     | hb_any
     ;
   }
@@ -2046,7 +2046,7 @@ struct ChainRuleSet
   {
     return
     + hb_iter (rule)
-    | hb_map ([&] (const OffsetTo<ChainRule> &_) -> bool { return (this+_).would_apply (c, lookup_context); })
+    | hb_map ([&] (const OffsetTo<ChainRule> &_) { return (this+_).would_apply (c, lookup_context); })
     | hb_any
     ;
   }
@@ -2056,7 +2056,7 @@ struct ChainRuleSet
     TRACE_APPLY (this);
     return_trace (
     + hb_iter (rule)
-    | hb_map ([&] (const OffsetTo<ChainRule> &_) -> bool { return (this+_).apply (c, lookup_context); })
+    | hb_map ([&] (const OffsetTo<ChainRule> &_) { return (this+_).apply (c, lookup_context); })
     | hb_any
     )
     ;
@@ -2089,7 +2089,7 @@ struct ChainContextFormat1
     + hb_zip (this+coverage, ruleSet)
     | hb_filter (*glyphs, hb_first)
     | hb_map (hb_second)
-    | hb_map ([&] (const OffsetTo<ChainRuleSet> &_) -> bool { return (this+_).intersects (glyphs, lookup_context); })
+    | hb_map ([&] (const OffsetTo<ChainRuleSet> &_) { return (this+_).intersects (glyphs, lookup_context); })
     | hb_any
     ;
   }
diff --git a/src/hb-ot-stat-table.hh b/src/hb-ot-stat-table.hh
index e6fa9b0bc..72d377281 100644
--- a/src/hb-ot-stat-table.hh
+++ b/src/hb-ot-stat-table.hh
@@ -289,7 +289,7 @@ struct STAT
     ;
 
     + get_axis_value_offsets ()
-    | hb_map ([&] (const OffsetTo<AxisValue>& _) -> const AxisValue* { return hb_addressof (this + _); })
+    | hb_map ([&] (const OffsetTo<AxisValue>& _) { return hb_addressof (this + _); })
     | hb_map (&AxisValue::get_value_name_id)
     | hb_sink (nameids_to_retain)
     ;
diff --git a/src/hb-ot-var-fvar-table.hh b/src/hb-ot-var-fvar-table.hh
index 3cdf61405..8b3b38ce9 100644
--- a/src/hb-ot-var-fvar-table.hh
+++ b/src/hb-ot-var-fvar-table.hh
@@ -290,12 +290,12 @@ struct fvar
     ;
 
     + hb_range ((unsigned) instanceCount)
-    | hb_map ([&] (const unsigned _) -> unsigned { return get_instance_subfamily_name_id (_); })
+    | hb_map ([&] (const unsigned _) { return get_instance_subfamily_name_id (_); })
     | hb_sink (nameids)
     ;
 
     + hb_range ((unsigned) instanceCount)
-    | hb_map ([&] (const unsigned _) -> unsigned { return get_instance_postscript_name_id (_); })
+    | hb_map ([&] (const unsigned _) { return get_instance_postscript_name_id (_); })
     | hb_sink (nameids)
     ;
   }
diff --git a/src/test-iter.cc b/src/test-iter.cc
index f834640ff..c36453d1f 100644
--- a/src/test-iter.cc
+++ b/src/test-iter.cc
@@ -203,8 +203,8 @@ main (int argc, char **argv)
   ;
 
   + hb_iter (src)
-  | hb_map ([&] (int i) -> int { return 1; })
-  | hb_reduce ([&] (int acc, int value) -> int { return acc; }, 2)
+  | hb_map ([&] (int i) { return 1; })
+  | hb_reduce ([&] (int acc, int value) { return acc; }, 2)
   ;
 
   using map_pair_t = hb_item_type<hb_map_t>;
@@ -251,8 +251,8 @@ main (int argc, char **argv)
 
   unsigned int temp3 = 0;
   + hb_iter(src)
-  | hb_map([&] (int i) -> int { return ++temp3; })
-  | hb_reduce([&] (float acc, int value) -> float { return acc + value; }, 0)
+  | hb_map([&] (int i) { return ++temp3; })
+  | hb_reduce([&] (float acc, int value) { return acc + value; }, 0)
   ;
   hb_map_destroy (result);
 
diff --git a/src/test-meta.cc b/src/test-meta.cc
index ffd360b0d..0b6e02c26 100644
--- a/src/test-meta.cc
+++ b/src/test-meta.cc
@@ -32,7 +32,6 @@
 int
 main (int argc, char **argv)
 {
-
   static_assert (hb_is_convertible (void, void), "");
   static_assert (hb_is_convertible (void, const void), "");
   static_assert (hb_is_convertible (const void, void), "");