[iter] Add hb_all, hb_any, hb_none

src/hb-iter.hh

@@ -130,7 +130,7 @@ static const struct
 {
   template <typename T>
   hb_iter_t (T)
-  operator () (const T& c) const
+  operator () (T&& c) const
   { return c.iter (); }
 
   /* Specialization for C arrays. */
@@ -490,6 +490,50 @@ static const struct
   }
 } hb_drain HB_UNUSED;
 
+/* hb-all, hb-any, hb-none. */
+
+static const struct
+{
+  template <typename Iterable,
+	    hb_enable_if (hb_is_iterable (Iterable))>
+  bool
+  operator () (Iterable&& c) const
+  {
+    for (auto it = hb_iter (c); it; ++it)
+      if (!*it)
+	return false;
+    return true;
+  }
+} hb_all HB_UNUSED;
+
+static const struct
+{
+  template <typename Iterable,
+	    hb_enable_if (hb_is_iterable (Iterable))>
+  bool
+  operator () (Iterable&& c) const
+  {
+    for (auto it = hb_iter (c); it; ++it)
+      if (it)
+	return true;
+    return false;
+  }
+} hb_any HB_UNUSED;
+
+static const struct
+{
+  template <typename Iterable,
+	    hb_enable_if (hb_is_iterable (Iterable))>
+  bool
+  operator () (Iterable&& c) const
+  {
+    for (auto it = hb_iter (c); it; ++it)
+      if (it)
+	return false;
+    return true;
+  }
+} hb_none HB_UNUSED;
+
 /*
  * Algorithms operating on iterators.
  */

src/test-iter.cc

@@ -137,6 +137,8 @@ main (int argc, char **argv)
 
   test_iterator (hb_zip (st, v));
 
+  hb_any (hb_zip (st, v));
+
   hb_array_t<hb_vector_t<int> > pa;
   pa->as_array ();