diff --git a/src/hb-aat-layout-common.hh b/src/hb-aat-layout-common.hh
index 3e83673c8..d8223dc8e 100644
--- a/src/hb-aat-layout-common.hh
+++ b/src/hb-aat-layout-common.hh
@@ -576,7 +576,7 @@ struct StateTable
 	  if (unlikely (stop > states))
 	    return_trace (false);
 	  for (const HBUSHORT *p = states; stop < p; p--)
-	    num_entries = hb_max (num_entries, *(p - 1) + 1);
+	    num_entries = hb_max (num_entries, *(p - 1) + 1u);
 	  state_neg = min_state;
 	}
       }
@@ -597,7 +597,7 @@ struct StateTable
 	  if (unlikely (stop < states))
 	    return_trace (false);
 	  for (const HBUSHORT *p = &states[state_pos * num_classes]; p < stop; p++)
-	    num_entries = hb_max (num_entries, *p + 1);
+	    num_entries = hb_max (num_entries, *p + 1u);
 	  state_pos = max_state + 1;
 	}
       }
diff --git a/src/hb-aat-layout-morx-table.hh b/src/hb-aat-layout-morx-table.hh
index 04027a61b..cf6766b04 100644
--- a/src/hb-aat-layout-morx-table.hh
+++ b/src/hb-aat-layout-morx-table.hh
@@ -337,9 +337,9 @@ struct ContextualSubtable
       const EntryData &data = entries[i].data;
 
       if (data.markIndex != 0xFFFF)
-	num_lookups = hb_max (num_lookups, 1 + data.markIndex);
+	num_lookups = hb_max (num_lookups, 1u + data.markIndex);
       if (data.currentIndex != 0xFFFF)
-	num_lookups = hb_max (num_lookups, 1 + data.currentIndex);
+	num_lookups = hb_max (num_lookups, 1u + data.currentIndex);
     }
 
     return_trace (substitutionTables.sanitize (c, this, num_lookups));
diff --git a/src/hb-algs.hh b/src/hb-algs.hh
index 05c98ef20..bc170b054 100644
--- a/src/hb-algs.hh
+++ b/src/hb-algs.hh
@@ -83,7 +83,8 @@ static inline constexpr uint16_t hb_uint16_swap (uint16_t v)
 static inline constexpr uint32_t hb_uint32_swap (uint32_t v)
 { return (hb_uint16_swap (v) << 16) | hb_uint16_swap (v >> 16); }
 
-template <typename Type, int Bytes = sizeof (Type)> struct BEInt;
+template <typename Type, int Bytes = sizeof (Type)>
+struct BEInt;
 template <typename Type>
 struct BEInt<Type, 1>
 {
@@ -124,14 +125,16 @@ struct BEInt<Type, 2>
 template <typename Type>
 struct BEInt<Type, 3>
 {
+  static_assert (!hb_is_signed (Type), "");
   public:
   BEInt () = default;
   constexpr BEInt (Type V) : v {uint8_t ((V >> 16) & 0xFF),
-			        uint8_t ((V >>  8) & 0xFF),
-			        uint8_t ((V      ) & 0xFF)} {}
+				uint8_t ((V >>  8) & 0xFF),
+				uint8_t ((V      ) & 0xFF)} {}
+
   constexpr operator Type () const { return (v[0] << 16)
-					     + (v[1] <<  8)
-					     + (v[2]      ); }
+					  + (v[1] <<  8)
+					  + (v[2]      ); }
   private: uint8_t v[3];
 };
 template <typename Type>
diff --git a/src/hb-open-type.hh b/src/hb-open-type.hh
index 28353e4e5..dc0ae1d98 100644
--- a/src/hb-open-type.hh
+++ b/src/hb-open-type.hh
@@ -53,14 +53,19 @@ namespace OT {
  */
 
 /* Integer types in big-endian order and no alignment requirement */
-template <typename Type, unsigned int Size = sizeof (Type)>
+template <typename Type,
+	  unsigned int Size = sizeof (Type)>
 struct IntType
 {
   typedef Type type;
-  typedef hb_conditional<hb_is_signed (Type), signed, unsigned> wide_type;
 
-  IntType& operator = (wide_type i) { v = i; return *this; }
-  operator wide_type () const { return v; }
+  IntType () = default;
+  explicit constexpr IntType (Type V) : v {V} {}
+  IntType& operator = (Type i) { v = i; return *this; }
+  /* For reason we define cast out operator for signed/unsigned, instead of Type, see:
+   * https://github.com/harfbuzz/harfbuzz/pull/2875/commits/09836013995cab2b9f07577a179ad7b024130467 */
+  operator hb_conditional<hb_is_signed (Type), signed, unsigned> () const { return v; }
+
   bool operator == (const IntType &o) const { return (Type) v == (Type) o.v; }
   bool operator != (const IntType &o) const { return !(*this == o); }
 
diff --git a/src/hb-ot-layout-common.hh b/src/hb-ot-layout-common.hh
index 4985d5e83..0a7e27b00 100644
--- a/src/hb-ot-layout-common.hh
+++ b/src/hb-ot-layout-common.hh
@@ -1788,7 +1788,7 @@ struct ClassDefFormat1
   }
 
   template <typename set_t>
-  bool collect_class (set_t *glyphs, unsigned int klass) const
+  bool collect_class (set_t *glyphs, unsigned klass) const
   {
     unsigned int count = classValue.len;
     for (unsigned int i = 0; i < count; i++)
@@ -1806,7 +1806,7 @@ struct ClassDefFormat1
       if (classValue[iter - start]) return true;
     return false;
   }
-  bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const
+  bool intersects_class (const hb_set_t *glyphs, uint16_t klass) const
   {
     unsigned int count = classValue.len;
     if (klass == 0)
@@ -1821,8 +1821,7 @@ struct ClassDefFormat1
     }
     /* TODO Speed up, using set overlap first? */
     /* TODO(iter) Rewrite as dagger. */
-    HBUINT16 k; /* TODO(constexpr) use constructor to initialize. */
-    k = klass;
+    HBUINT16 k {klass};
     const HBUINT16 *arr = classValue.arrayZ;
     for (unsigned int i = 0; i < count; i++)
       if (arr[i] == k && glyphs->has (startGlyph + i))
@@ -1974,7 +1973,7 @@ struct ClassDefFormat2
 	return true;
     return false;
   }
-  bool intersects_class (const hb_set_t *glyphs, unsigned int klass) const
+  bool intersects_class (const hb_set_t *glyphs, uint16_t klass) const
   {
     unsigned int count = rangeRecord.len;
     if (klass == 0)
@@ -1995,8 +1994,7 @@ struct ClassDefFormat2
     }
     /* TODO Speed up, using set overlap first? */
     /* TODO(iter) Rewrite as dagger. */
-    HBUINT16 k; /* TODO(constexpr) use constructor to initialize. */
-    k = klass;
+    HBUINT16 k {klass};
     const RangeRecord *arr = rangeRecord.arrayZ;
     for (unsigned int i = 0; i < count; i++)
       if (arr[i].value == k && arr[i].intersects (glyphs))
diff --git a/src/hb-ot-layout-gsubgpos.hh b/src/hb-ot-layout-gsubgpos.hh
index aa46befbe..0f55a10a6 100644
--- a/src/hb-ot-layout-gsubgpos.hh
+++ b/src/hb-ot-layout-gsubgpos.hh
@@ -2323,12 +2323,7 @@ struct ChainRule
   {
     c->copy (len);
     for (const auto g : it)
-    {
-      /* TODO(constexpr) Simplify. */
-      HBUINT16 gid;
-      gid = g;
-      c->copy (gid);
-    }
+      c->copy ((HBUINT16) g);
   }
 
   ChainRule* copy (hb_serialize_context_t *c,