[>64k:layout] Templatize SingleSubst

src/OT/Layout/GSUB/SingleSubst.hh

@@ -13,9 +13,9 @@ struct SingleSubst
 {
   protected:
   union {
-  HBUINT16              format;         /* Format identifier */
-  SingleSubstFormat1    format1;
-  SingleSubstFormat2    format2;
+  HBUINT16				format;         /* Format identifier */
+  SingleSubstFormat1_3<SmallTypes>	format1;
+  SingleSubstFormat2_4<SmallTypes>	format2;
   } u;
 
   public:

src/OT/Layout/GSUB/SingleSubstFormat1.hh

@@ -7,18 +7,20 @@ namespace OT {
 namespace Layout {
 namespace GSUB_impl {
 
-struct SingleSubstFormat1
+template <typename Types>
+struct SingleSubstFormat1_3
 {
   protected:
   HBUINT16      format;                 /* Format identifier--format = 1 */
-  Offset16To<Coverage>
+  typename Types::template OffsetTo<Coverage>
                 coverage;               /* Offset to Coverage table--from
                                          * beginning of Substitution table */
-  HBUINT16      deltaGlyphID;           /* Add to original GlyphID to get
+  typename Types::HBUINT
+                deltaGlyphID;           /* Add to original GlyphID to get
                                          * substitute GlyphID, modulo 0x10000 */
 
   public:
-  DEFINE_SIZE_STATIC (6);
+  DEFINE_SIZE_STATIC (2 + 2 * Types::size);
 
   bool sanitize (hb_sanitize_context_t *c) const
   {

src/OT/Layout/GSUB/SingleSubstFormat2.hh

@@ -7,19 +7,20 @@ namespace OT {
 namespace Layout {
 namespace GSUB_impl {
 
-struct SingleSubstFormat2
+template <typename Types>
+struct SingleSubstFormat2_4
 {
   protected:
   HBUINT16      format;                 /* Format identifier--format = 2 */
-  Offset16To<Coverage>
+  typename Types::template OffsetTo<Coverage>
                 coverage;               /* Offset to Coverage table--from
                                          * beginning of Substitution table */
-  Array16Of<HBGlyphID16>
+  Array16Of<typename Types::HBGlyphID>
                 substitute;             /* Array of substitute
                                          * GlyphIDs--ordered by Coverage Index */
 
   public:
-  DEFINE_SIZE_ARRAY (6, substitute);
+  DEFINE_SIZE_ARRAY (4 + Types::size, substitute);
 
   bool sanitize (hb_sanitize_context_t *c) const
   {