diff --git a/src/Makefile.sources b/src/Makefile.sources
index 80b8e261c41f7845d59ec06e781940a6543dc16d..0a383dfc006c9945be039b256f0dc3ac902ab080 100644
--- a/src/Makefile.sources
+++ b/src/Makefile.sources
@@ -52,6 +52,7 @@ HB_BASE_sources = \
 	hb-string-array.hh \
 	hb-unicode-private.hh \
 	hb-unicode.cc \
+	hb-vector-private.hh \
 	hb-utf-private.hh \
 	hb-warning.cc \
 	$(NULL)
diff --git a/src/hb-dsalgs.hh b/src/hb-dsalgs.hh
index 36395db29d319a96a130f5b8997db40c78d59fd1..8cbe6584b29c8d9308be4464aab93c0d8597a7d3 100644
--- a/src/hb-dsalgs.hh
+++ b/src/hb-dsalgs.hh
@@ -488,303 +488,6 @@ hb_codepoint_parse (const char *s, unsigned int len, int base, hb_codepoint_t *o
 }
 
 
-#define HB_VECTOR_INIT {0, 0, false, nullptr}
-template <typename Type, unsigned int StaticSize=8>
-struct hb_vector_t
-{
-  unsigned int len;
-  unsigned int allocated; /* == 0 means allocation failed. */
-  Type *arrayZ;
-  Type static_array[StaticSize];
-
-  void init (void)
-  {
-    len = 0;
-    allocated = ARRAY_LENGTH (static_array);
-    arrayZ = static_array;
-  }
-
-  inline Type& operator [] (unsigned int i)
-  {
-    if (unlikely (i >= len))
-      return Crap (Type);
-    return arrayZ[i];
-  }
-  inline const Type& operator [] (unsigned int i) const
-  {
-    if (unlikely (i >= len))
-      return Null(Type);
-    return arrayZ[i];
-  }
-
-  inline Type *push (void)
-  {
-    if (unlikely (!resize (len + 1)))
-      return &Crap(Type);
-    return &arrayZ[len - 1];
-  }
-  inline Type *push (const Type& v)
-  {
-    Type *p = push ();
-    *p = v;
-    return p;
-  }
-
-  /* Allocate for size but don't adjust len. */
-  inline bool alloc (unsigned int size)
-  {
-    if (unlikely (!allocated))
-      return false;
-
-    if (likely (size <= allocated))
-      return true;
-
-    /* Reallocate */
-
-    unsigned int new_allocated = allocated;
-    while (size >= new_allocated)
-      new_allocated += (new_allocated >> 1) + 8;
-
-    Type *new_array = nullptr;
-
-    if (arrayZ == static_array)
-    {
-      new_array = (Type *) calloc (new_allocated, sizeof (Type));
-      if (new_array)
-        memcpy (new_array, arrayZ, len * sizeof (Type));
-    }
-    else
-    {
-      bool overflows = (new_allocated < allocated) || hb_unsigned_mul_overflows (new_allocated, sizeof (Type));
-      if (likely (!overflows))
-        new_array = (Type *) realloc (arrayZ, new_allocated * sizeof (Type));
-    }
-
-    if (unlikely (!new_array))
-    {
-      allocated = 0;
-      return false;
-    }
-
-    arrayZ = new_array;
-    allocated = new_allocated;
-
-    return true;
-  }
-
-  inline bool resize (int size_)
-  {
-    unsigned int size = size_ < 0 ? 0u : (unsigned int) size_;
-    if (!alloc (size))
-      return false;
-
-    if (size > len)
-      memset (arrayZ + len, 0, (size - len) * sizeof (*arrayZ));
-
-    len = size;
-    return true;
-  }
-
-  inline void pop (void)
-  {
-    if (!len) return;
-    len--;
-  }
-
-  inline void remove (unsigned int i)
-  {
-     if (unlikely (i >= len))
-       return;
-     memmove (static_cast<void *> (&arrayZ[i]),
-	      static_cast<void *> (&arrayZ[i + 1]),
-	      (len - i - 1) * sizeof (Type));
-     len--;
-  }
-
-  inline void shrink (int size_)
-  {
-    unsigned int size = size_ < 0 ? 0u : (unsigned int) size_;
-     if (size < len)
-       len = size;
-  }
-
-  template <typename T>
-  inline Type *find (T v) {
-    for (unsigned int i = 0; i < len; i++)
-      if (arrayZ[i] == v)
-	return &arrayZ[i];
-    return nullptr;
-  }
-  template <typename T>
-  inline const Type *find (T v) const {
-    for (unsigned int i = 0; i < len; i++)
-      if (arrayZ[i] == v)
-	return &arrayZ[i];
-    return nullptr;
-  }
-
-  inline void qsort (int (*cmp)(const void*, const void*))
-  {
-    ::qsort (arrayZ, len, sizeof (Type), cmp);
-  }
-
-  inline void qsort (void)
-  {
-    ::qsort (arrayZ, len, sizeof (Type), Type::cmp);
-  }
-
-  inline void qsort (unsigned int start, unsigned int end)
-  {
-    ::qsort (arrayZ + start, end - start, sizeof (Type), Type::cmp);
-  }
-
-  template <typename T>
-  inline Type *lsearch (const T &x)
-  {
-    for (unsigned int i = 0; i < len; i++)
-      if (0 == this->arrayZ[i].cmp (&x))
-	return &arrayZ[i];
-    return nullptr;
-  }
-
-  template <typename T>
-  inline Type *bsearch (const T &x)
-  {
-    unsigned int i;
-    return bfind (x, &i) ? &arrayZ[i] : nullptr;
-  }
-  template <typename T>
-  inline const Type *bsearch (const T &x) const
-  {
-    unsigned int i;
-    return bfind (x, &i) ? &arrayZ[i] : nullptr;
-  }
-  template <typename T>
-  inline bool bfind (const T &x, unsigned int *i) const
-  {
-    int min = 0, max = (int) this->len - 1;
-    while (min <= max)
-    {
-      int mid = (min + max) / 2;
-      int c = this->arrayZ[mid].cmp (&x);
-      if (c < 0)
-        max = mid - 1;
-      else if (c > 0)
-        min = mid + 1;
-      else
-      {
-        *i = mid;
-	return true;
-      }
-    }
-    if (max < 0 || (max < (int) this->len && this->arrayZ[max].cmp (&x) > 0))
-      max++;
-    *i = max;
-    return false;
-  }
-
-  inline void fini (void)
-  {
-    if (arrayZ != static_array)
-      free (arrayZ);
-    arrayZ = nullptr;
-    allocated = len = 0;
-  }
-};
-
-
-#define HB_LOCKABLE_SET_INIT {HB_VECTOR_INIT}
-template <typename item_t, typename lock_t>
-struct hb_lockable_set_t
-{
-  hb_vector_t <item_t, 1> items;
-
-  inline void init (void) { items.init (); }
-
-  template <typename T>
-  inline item_t *replace_or_insert (T v, lock_t &l, bool replace)
-  {
-    l.lock ();
-    item_t *item = items.find (v);
-    if (item) {
-      if (replace) {
-	item_t old = *item;
-	*item = v;
-	l.unlock ();
-	old.fini ();
-      }
-      else {
-        item = nullptr;
-	l.unlock ();
-      }
-    } else {
-      item = items.push (v);
-      l.unlock ();
-    }
-    return item;
-  }
-
-  template <typename T>
-  inline void remove (T v, lock_t &l)
-  {
-    l.lock ();
-    item_t *item = items.find (v);
-    if (item) {
-      item_t old = *item;
-      *item = items[items.len - 1];
-      items.pop ();
-      l.unlock ();
-      old.fini ();
-    } else {
-      l.unlock ();
-    }
-  }
-
-  template <typename T>
-  inline bool find (T v, item_t *i, lock_t &l)
-  {
-    l.lock ();
-    item_t *item = items.find (v);
-    if (item)
-      *i = *item;
-    l.unlock ();
-    return !!item;
-  }
-
-  template <typename T>
-  inline item_t *find_or_insert (T v, lock_t &l)
-  {
-    l.lock ();
-    item_t *item = items.find (v);
-    if (!item) {
-      item = items.push (v);
-    }
-    l.unlock ();
-    return item;
-  }
-
-  inline void fini (lock_t &l)
-  {
-    if (!items.len) {
-      /* No need for locking. */
-      items.fini ();
-      return;
-    }
-    l.lock ();
-    while (items.len) {
-      item_t old = items[items.len - 1];
-	items.pop ();
-	l.unlock ();
-	old.fini ();
-	l.lock ();
-    }
-    items.fini ();
-    l.unlock ();
-  }
-
-};
-
-
 template <typename Type>
 struct hb_auto_t : Type
 {
diff --git a/src/hb-object-private.hh b/src/hb-object-private.hh
index 36d27a8913ef373e56c2ac8b40c806d976969344..66a35df05a56198ecb41511ecc7fab79f2e88e01 100644
--- a/src/hb-object-private.hh
+++ b/src/hb-object-private.hh
@@ -35,9 +35,108 @@
 #include "hb-private.hh"
 #include "hb-atomic-private.hh"
 #include "hb-mutex-private.hh"
+#include "hb-vector-private.hh"
 
 
-/* reference_count */
+/*
+ * Lockable set
+ */
+
+#define HB_LOCKABLE_SET_INIT {HB_VECTOR_INIT}
+template <typename item_t, typename lock_t>
+struct hb_lockable_set_t
+{
+  hb_vector_t <item_t, 1> items;
+
+  inline void init (void) { items.init (); }
+
+  template <typename T>
+  inline item_t *replace_or_insert (T v, lock_t &l, bool replace)
+  {
+    l.lock ();
+    item_t *item = items.find (v);
+    if (item) {
+      if (replace) {
+	item_t old = *item;
+	*item = v;
+	l.unlock ();
+	old.fini ();
+      }
+      else {
+        item = nullptr;
+	l.unlock ();
+      }
+    } else {
+      item = items.push (v);
+      l.unlock ();
+    }
+    return item;
+  }
+
+  template <typename T>
+  inline void remove (T v, lock_t &l)
+  {
+    l.lock ();
+    item_t *item = items.find (v);
+    if (item) {
+      item_t old = *item;
+      *item = items[items.len - 1];
+      items.pop ();
+      l.unlock ();
+      old.fini ();
+    } else {
+      l.unlock ();
+    }
+  }
+
+  template <typename T>
+  inline bool find (T v, item_t *i, lock_t &l)
+  {
+    l.lock ();
+    item_t *item = items.find (v);
+    if (item)
+      *i = *item;
+    l.unlock ();
+    return !!item;
+  }
+
+  template <typename T>
+  inline item_t *find_or_insert (T v, lock_t &l)
+  {
+    l.lock ();
+    item_t *item = items.find (v);
+    if (!item) {
+      item = items.push (v);
+    }
+    l.unlock ();
+    return item;
+  }
+
+  inline void fini (lock_t &l)
+  {
+    if (!items.len) {
+      /* No need for locking. */
+      items.fini ();
+      return;
+    }
+    l.lock ();
+    while (items.len) {
+      item_t old = items[items.len - 1];
+	items.pop ();
+	l.unlock ();
+	old.fini ();
+	l.lock ();
+    }
+    items.fini ();
+    l.unlock ();
+  }
+
+};
+
+
+/*
+ * Reference-count.
+ */
 
 #define HB_REFERENCE_COUNT_INERT_VALUE 0
 #define HB_REFERENCE_COUNT_POISON_VALUE -0x0000DEAD
@@ -89,7 +188,9 @@ struct hb_user_data_array_t
 };
 
 
-/* object_header */
+/*
+ * Object header
+ */
 
 struct hb_object_header_t
 {
@@ -103,7 +204,9 @@ struct hb_object_header_t
 };
 
 
-/* object */
+/*
+ * Object
+ */
 
 template <typename Type>
 static inline void hb_object_trace (const Type *obj, const char *function)
diff --git a/src/hb-vector-private.hh b/src/hb-vector-private.hh
new file mode 100644
index 0000000000000000000000000000000000000000..157fbd51b4c9738638a9029f451dac16e93c37d7
--- /dev/null
+++ b/src/hb-vector-private.hh
@@ -0,0 +1,239 @@
+/*
+ * Copyright © 2017,2018  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Red Hat Author(s): Behdad Esfahbod
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_VECTOR_PRIVATE_HH
+#define HB_VECTOR_PRIVATE_HH
+
+#include "hb-private.hh"
+
+
+#define HB_VECTOR_INIT {0, 0, false, nullptr}
+template <typename Type, unsigned int StaticSize=8>
+struct hb_vector_t
+{
+  unsigned int len;
+  unsigned int allocated; /* == 0 means allocation failed. */
+  Type *arrayZ;
+  Type static_array[StaticSize];
+
+  void init (void)
+  {
+    len = 0;
+    allocated = ARRAY_LENGTH (static_array);
+    arrayZ = static_array;
+  }
+
+  inline Type& operator [] (unsigned int i)
+  {
+    if (unlikely (i >= len))
+      return Crap (Type);
+    return arrayZ[i];
+  }
+  inline const Type& operator [] (unsigned int i) const
+  {
+    if (unlikely (i >= len))
+      return Null(Type);
+    return arrayZ[i];
+  }
+
+  inline Type *push (void)
+  {
+    if (unlikely (!resize (len + 1)))
+      return &Crap(Type);
+    return &arrayZ[len - 1];
+  }
+  inline Type *push (const Type& v)
+  {
+    Type *p = push ();
+    *p = v;
+    return p;
+  }
+
+  /* Allocate for size but don't adjust len. */
+  inline bool alloc (unsigned int size)
+  {
+    if (unlikely (!allocated))
+      return false;
+
+    if (likely (size <= allocated))
+      return true;
+
+    /* Reallocate */
+
+    unsigned int new_allocated = allocated;
+    while (size >= new_allocated)
+      new_allocated += (new_allocated >> 1) + 8;
+
+    Type *new_array = nullptr;
+
+    if (arrayZ == static_array)
+    {
+      new_array = (Type *) calloc (new_allocated, sizeof (Type));
+      if (new_array)
+        memcpy (new_array, arrayZ, len * sizeof (Type));
+    }
+    else
+    {
+      bool overflows = (new_allocated < allocated) || hb_unsigned_mul_overflows (new_allocated, sizeof (Type));
+      if (likely (!overflows))
+        new_array = (Type *) realloc (arrayZ, new_allocated * sizeof (Type));
+    }
+
+    if (unlikely (!new_array))
+    {
+      allocated = 0;
+      return false;
+    }
+
+    arrayZ = new_array;
+    allocated = new_allocated;
+
+    return true;
+  }
+
+  inline bool resize (int size_)
+  {
+    unsigned int size = size_ < 0 ? 0u : (unsigned int) size_;
+    if (!alloc (size))
+      return false;
+
+    if (size > len)
+      memset (arrayZ + len, 0, (size - len) * sizeof (*arrayZ));
+
+    len = size;
+    return true;
+  }
+
+  inline void pop (void)
+  {
+    if (!len) return;
+    len--;
+  }
+
+  inline void remove (unsigned int i)
+  {
+     if (unlikely (i >= len))
+       return;
+     memmove (static_cast<void *> (&arrayZ[i]),
+	      static_cast<void *> (&arrayZ[i + 1]),
+	      (len - i - 1) * sizeof (Type));
+     len--;
+  }
+
+  inline void shrink (int size_)
+  {
+    unsigned int size = size_ < 0 ? 0u : (unsigned int) size_;
+     if (size < len)
+       len = size;
+  }
+
+  template <typename T>
+  inline Type *find (T v) {
+    for (unsigned int i = 0; i < len; i++)
+      if (arrayZ[i] == v)
+	return &arrayZ[i];
+    return nullptr;
+  }
+  template <typename T>
+  inline const Type *find (T v) const {
+    for (unsigned int i = 0; i < len; i++)
+      if (arrayZ[i] == v)
+	return &arrayZ[i];
+    return nullptr;
+  }
+
+  inline void qsort (int (*cmp)(const void*, const void*))
+  {
+    ::qsort (arrayZ, len, sizeof (Type), cmp);
+  }
+
+  inline void qsort (void)
+  {
+    ::qsort (arrayZ, len, sizeof (Type), Type::cmp);
+  }
+
+  inline void qsort (unsigned int start, unsigned int end)
+  {
+    ::qsort (arrayZ + start, end - start, sizeof (Type), Type::cmp);
+  }
+
+  template <typename T>
+  inline Type *lsearch (const T &x)
+  {
+    for (unsigned int i = 0; i < len; i++)
+      if (0 == this->arrayZ[i].cmp (&x))
+	return &arrayZ[i];
+    return nullptr;
+  }
+
+  template <typename T>
+  inline Type *bsearch (const T &x)
+  {
+    unsigned int i;
+    return bfind (x, &i) ? &arrayZ[i] : nullptr;
+  }
+  template <typename T>
+  inline const Type *bsearch (const T &x) const
+  {
+    unsigned int i;
+    return bfind (x, &i) ? &arrayZ[i] : nullptr;
+  }
+  template <typename T>
+  inline bool bfind (const T &x, unsigned int *i) const
+  {
+    int min = 0, max = (int) this->len - 1;
+    while (min <= max)
+    {
+      int mid = (min + max) / 2;
+      int c = this->arrayZ[mid].cmp (&x);
+      if (c < 0)
+        max = mid - 1;
+      else if (c > 0)
+        min = mid + 1;
+      else
+      {
+        *i = mid;
+	return true;
+      }
+    }
+    if (max < 0 || (max < (int) this->len && this->arrayZ[max].cmp (&x) > 0))
+      max++;
+    *i = max;
+    return false;
+  }
+
+  inline void fini (void)
+  {
+    if (arrayZ != static_array)
+      free (arrayZ);
+    arrayZ = nullptr;
+    allocated = len = 0;
+  }
+};
+
+
+#endif /* HB_VECTOR_PRIVATE_HH */