Add hb-meta.hh for meta-programming

src/Makefile.sources

@@ -41,6 +41,7 @@ HB_BASE_sources = \
 	hb-machinery.hh \
 	hb-map.cc \
 	hb-map.hh \
+	hb-meta.hh \
 	hb-mutex.hh \
 	hb-null.hh \
 	hb-object.hh \

src/hb-dsalgs.hh

@@ -31,10 +31,6 @@
 #include "hb-null.hh"
 
 
-/* Void! For when we need a expression-type of void. */
-struct hb_void_t { typedef void value; };
-
-
 /*
  * Pair
  */

src/hb-iter.hh

@@ -29,6 +29,7 @@
 
 #include "hb.hh"
 #include "hb-dsalgs.hh" // for hb_addressof
+#include "hb-meta.hh"
 #include "hb-null.hh"
 
 

src/hb-meta.hh

@@ -0,0 +1,40 @@
+/*
+ * Copyright © 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.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_META_HH
+#define HB_META_HH
+
+#include "hb.hh"
+
+
+/* Void! For when we need a expression-type of void. */
+struct hb_void_t { typedef void value; };
+
+struct hb_true_t { enum { value = true }; };
+struct hb_false_t { enum { value = false }; };
+
+
+#endif /* HB_META_HH */

src/hb.hh

@@ -628,10 +628,11 @@ template <typename T> struct hb_remove_pointer<T *> { typedef T value; };
  * They express dependency amongst themselves, but no other file should include
  * them directly.*/
 #include "hb-atomic.hh"
+#include "hb-meta.hh"
 #include "hb-mutex.hh"
 #include "hb-null.hh"
 #include "hb-dsalgs.hh"	// Requires: hb-null
-#include "hb-iter.hh"	// Requires: hb-dsalgs hb-null
+#include "hb-iter.hh"	// Requires: hb-dsalgs hb-meta hb-null
 #include "hb-debug.hh"	// Requires: hb-atomic hb-dsalgs
 #include "hb-array.hh"	// Requires: hb-dsalgs hb-iter hb-null
 #include "hb-vector.hh"	// Requires: hb-array hb-null