diff --git a/src/hb-open-file-private.hh b/src/hb-open-file-private.hh
index 53e947a65..d8d70e5e1 100644
--- a/src/hb-open-file-private.hh
+++ b/src/hb-open-file-private.hh
@@ -139,8 +139,9 @@ struct TTCHeaderVersion1
   LongOffsetLongArrayOf<OffsetTable>
 		table;		/* Array of offsets to the OffsetTable for each font
 				 * from the beginning of the file */
+  public:
+  DEFINE_SIZE_STATIC (12);
 };
-ASSERT_SIZE (TTCHeaderVersion1, 12);
 
 struct TTCHeader
 {
diff --git a/src/hb-open-type-private.hh b/src/hb-open-type-private.hh
index aab85fd8a..56a8baeb5 100644
--- a/src/hb-open-type-private.hh
+++ b/src/hb-open-type-private.hh
@@ -96,6 +96,15 @@ inline Type& StructAfter(TObject &X)
   static const unsigned int static_size = (size); \
   static const unsigned int min_size = (size)
 
+/* Size signifying variable-sized array */
+#define VAR 1
+#define VAR0 (VAR+0)
+
+#define DEFINE_SIZE_VAR0(size) \
+  inline void _size_assertion (void) const \
+  { ASSERT_STATIC (sizeof (*this) == (size)); } \
+  static const unsigned int min_size = (size)
+
 #define DEFINE_SIZE_VAR(size, _var_type) \
   inline void _size_assertion (void) const \
   { ASSERT_STATIC (sizeof (*this) == (size) + VAR0 * sizeof (_var_type)); } \
@@ -397,8 +406,9 @@ struct Tag : ULONG
   /* What the char* converters return is NOT nul-terminated.  Print using "%.4s" */
   inline operator const char* (void) const { return CharP(this); }
   inline operator char* (void) { return CharP(this); }
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (Tag, 4);
 DEFINE_NULL_DATA (Tag, "    ");
 
 /* Glyph index number, same as uint16 (length = 16 bits) */
@@ -423,8 +433,9 @@ struct CheckSum : ULONG
       Sum += *Table++;
     return Sum;
   }
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (CheckSum, 4);
 
 
 /*
@@ -442,8 +453,9 @@ struct FixedVersion
 
   USHORT major;
   USHORT minor;
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (FixedVersion, 4);
 
 
 
@@ -577,6 +589,8 @@ struct GenericArrayOf
   public:
   LenType len;
 /*Type array[VAR];*/
+  public:
+  DEFINE_SIZE_VAR0 (sizeof (LenType));
 };
 
 /* An array with a USHORT number of elements. */
diff --git a/src/hb-ot-layout-common-private.hh b/src/hb-ot-layout-common-private.hh
index 7215415f8..dc1229f27 100644
--- a/src/hb-ot-layout-common-private.hh
+++ b/src/hb-ot-layout-common-private.hh
@@ -216,11 +216,11 @@ struct Script
   RecordArrayOf<LangSys>
 		langSys;	/* Array of LangSysRecords--listed
 				 * alphabetically by LangSysTag */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (Script, 4);
 
 typedef RecordListOf<Script> ScriptList;
-ASSERT_SIZE (ScriptList, 2);
 
 
 struct Feature
@@ -247,11 +247,11 @@ struct Feature
 				 * to the beginning of the Feature Table; = Null
 				 * if not required */
   IndexArray	 lookupIndex;	/* Array of LookupList indices */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (Feature, 4);
 
 typedef RecordListOf<Feature> FeatureList;
-ASSERT_SIZE (FeatureList, 2);
 
 
 struct LookupFlag : USHORT
@@ -266,8 +266,9 @@ struct LookupFlag : USHORT
     Reserved		= 0x00E0u,
     MarkAttachmentType	= 0xFF00u
   };
+  public:
+  DEFINE_SIZE_STATIC (2);
 };
-ASSERT_SIZE (LookupFlag, 2);
 
 struct Lookup
 {
@@ -310,7 +311,6 @@ struct Lookup
 };
 
 typedef OffsetListOf<Lookup> LookupList;
-ASSERT_SIZE (LookupList, 2);
 
 
 /*
@@ -345,8 +345,9 @@ struct CoverageFormat1
   USHORT	coverageFormat;	/* Format identifier--format = 1 */
   ArrayOf<GlyphID>
 		glyphArray;	/* Array of GlyphIDs--in numerical order */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (CoverageFormat1, 4);
 
 struct CoverageRangeRecord
 {
@@ -405,8 +406,9 @@ struct CoverageFormat2
 		rangeRecord;	/* Array of glyph ranges--ordered by
 				 * Start GlyphID. rangeCount entries
 				 * long */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (CoverageFormat2, 4);
 
 struct Coverage
 {
@@ -466,8 +468,9 @@ struct ClassDefFormat1
   GlyphID	startGlyph;		/* First GlyphID of the classValueArray */
   ArrayOf<USHORT>
 		classValue;		/* Array of Class Values--one per GlyphID */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (ClassDefFormat1, 6);
 
 struct ClassRangeRecord
 {
@@ -523,8 +526,9 @@ struct ClassDefFormat2
   ArrayOf<ClassRangeRecord>
 		rangeRecord;	/* Array of glyph ranges--ordered by
 				 * Start GlyphID */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (ClassDefFormat2, 4);
 
 struct ClassDef
 {
diff --git a/src/hb-ot-layout-gdef-private.hh b/src/hb-ot-layout-gdef-private.hh
index e6cf7b84c..4e0667351 100644
--- a/src/hb-ot-layout-gdef-private.hh
+++ b/src/hb-ot-layout-gdef-private.hh
@@ -38,7 +38,6 @@
 
 typedef ArrayOf<USHORT> AttachPoint;	/* Array of contour point indices--in
 					 * increasing numerical order */
-ASSERT_SIZE (AttachPoint, 2);
 
 struct AttachList
 {
@@ -80,8 +79,9 @@ struct AttachList
   OffsetArrayOf<AttachPoint>
 		attachPoint;		/* Array of AttachPoint tables
 					 * in Coverage Index order */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (AttachList, 4);
 
 /*
  * Ligature Caret Table
@@ -106,8 +106,9 @@ struct CaretValueFormat1
   private:
   USHORT	caretValueFormat;	/* Format identifier--format = 1 */
   SHORT		coordinate;		/* X or Y value, in design units */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (CaretValueFormat1, 4);
 
 struct CaretValueFormat2
 {
@@ -132,8 +133,9 @@ struct CaretValueFormat2
   private:
   USHORT	caretValueFormat;	/* Format identifier--format = 2 */
   USHORT	caretValuePoint;	/* Contour point index on glyph */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (CaretValueFormat2, 4);
 
 struct CaretValueFormat3
 {
@@ -159,8 +161,9 @@ struct CaretValueFormat3
 		deviceTable;		/* Offset to Device table for X or Y
 					 * value--from beginning of CaretValue
 					 * table */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (CaretValueFormat3, 6);
 
 struct CaretValue
 {
@@ -222,8 +225,9 @@ struct LigGlyph
 		carets;			/* Offset array of CaretValue tables
 					 * --from beginning of LigGlyph table
 					 * --in increasing coordinate order */
+  public:
+  DEFINE_SIZE_STATIC (2);
 };
-ASSERT_SIZE (LigGlyph, 2);
 
 struct LigCaretList
 {
@@ -257,8 +261,9 @@ struct LigCaretList
   OffsetArrayOf<LigGlyph>
 		ligGlyph;		/* Array of LigGlyph tables
 					 * in Coverage Index order */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (LigCaretList, 4);
 
 
 struct MarkGlyphSetsFormat1
@@ -276,8 +281,9 @@ struct MarkGlyphSetsFormat1
   LongOffsetArrayOf<Coverage>
 		coverage;		/* Array of long offsets to mark set
 					 * coverage tables */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (MarkGlyphSetsFormat1, 4);
 
 struct MarkGlyphSets
 {
diff --git a/src/hb-ot-layout-gpos-private.hh b/src/hb-ot-layout-gpos-private.hh
index eb53ac14e..65e26ebb7 100644
--- a/src/hb-ot-layout-gpos-private.hh
+++ b/src/hb-ot-layout-gpos-private.hh
@@ -202,7 +202,6 @@ struct ValueFormat : USHORT
     return true;
   }
 };
-ASSERT_SIZE (ValueFormat, 2);
 
 
 struct AnchorFormat1
@@ -226,8 +225,9 @@ struct AnchorFormat1
   USHORT	format;			/* Format identifier--format = 1 */
   SHORT		xCoordinate;		/* Horizontal value--in design units */
   SHORT		yCoordinate;		/* Vertical value--in design units */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (AnchorFormat1, 6);
 
 struct AnchorFormat2
 {
@@ -258,8 +258,9 @@ struct AnchorFormat2
   SHORT		xCoordinate;		/* Horizontal value--in design units */
   SHORT		yCoordinate;		/* Vertical value--in design units */
   USHORT	anchorPoint;		/* Index to glyph contour point */
+  public:
+  DEFINE_SIZE_STATIC (8);
 };
-ASSERT_SIZE (AnchorFormat2, 8);
 
 struct AnchorFormat3
 {
@@ -298,8 +299,9 @@ struct AnchorFormat3
 		yDeviceTable;		/* Offset to Device table for Y
 					 * coordinate-- from beginning of
 					 * Anchor table (may be NULL) */
+  public:
+  DEFINE_SIZE_STATIC (10);
 };
-ASSERT_SIZE (AnchorFormat3, 10);
 
 struct Anchor
 {
@@ -421,8 +423,9 @@ struct MarkArray
   private:
   ArrayOf<MarkRecord>
 		markRecord;	/* Array of MarkRecords--in Coverage order */
+  public:
+  DEFINE_SIZE_STATIC (2);
 };
-ASSERT_SIZE (MarkArray, 2);
 
 
 /* Lookups */
@@ -669,8 +672,9 @@ struct PairPosFormat1
   OffsetArrayOf<PairSet>
 		pairSet;		/* Array of PairSet tables
 					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_STATIC (10);
 };
-ASSERT_SIZE (PairPosFormat1, 10);
 
 struct PairPosFormat2
 {
@@ -1014,8 +1018,9 @@ struct CursivePosFormat1
   ArrayOf<EntryExitRecord>
 		entryExitRecord;	/* Array of EntryExit records--in
 					 * Coverage Index order */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (CursivePosFormat1, 6);
 
 struct CursivePos
 {
@@ -1075,11 +1080,9 @@ struct MarkBasePosFormat1
       j--;
     } while (_hb_ot_layout_skip_mark (context->layout->face, IN_INFO (j), LookupFlag::IgnoreMarks, &property));
 
-#if 0
-    /* The following assertion is too strong. */
-    if (!(property & HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH))
+    /* The following assertion is too strong, so we've disabled it. */
+    if (false && !(property & HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH))
       return false;
-#endif
 
     unsigned int base_index = (this+baseCoverage) (IN_GLYPH (j));
     if (base_index == NOT_COVERED)
@@ -1112,8 +1115,9 @@ struct MarkBasePosFormat1
   OffsetTo<BaseArray>
 		baseArray;		/* Offset to BaseArray table--from
 					 * beginning of MarkBasePos subtable */
+  public:
+  DEFINE_SIZE_STATIC (12);
 };
-ASSERT_SIZE (MarkBasePosFormat1, 12);
 
 struct MarkBasePos
 {
@@ -1178,11 +1182,9 @@ struct MarkLigPosFormat1
       j--;
     } while (_hb_ot_layout_skip_mark (context->layout->face, IN_INFO (j), LookupFlag::IgnoreMarks, &property));
 
-#if 0
-    /* The following assertion is too strong. */
-    if (!(property & HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE))
+    /* The following assertion is too strong, so we've disabled it. */
+    if (false && !(property & HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE))
       return false;
-#endif
 
     unsigned int lig_index = (this+ligatureCoverage) (IN_GLYPH (j));
     if (lig_index == NOT_COVERED)
@@ -1237,8 +1239,9 @@ struct MarkLigPosFormat1
   OffsetTo<LigatureArray>
 		ligatureArray;		/* Offset to LigatureArray table--from
 					 * beginning of MarkLigPos subtable */
+  public:
+  DEFINE_SIZE_STATIC (12);
 };
-ASSERT_SIZE (MarkLigPosFormat1, 12);
 
 struct MarkLigPos
 {
@@ -1341,8 +1344,9 @@ struct MarkMarkPosFormat1
   OffsetTo<Mark2Array>
 		mark2Array;		/* Offset to Mark2Array table--from
 					 * beginning of MarkMarkPos subtable */
+  public:
+  DEFINE_SIZE_STATIC (12);
 };
-ASSERT_SIZE (MarkMarkPosFormat1, 12);
 
 struct MarkMarkPos
 {
@@ -1567,7 +1571,6 @@ struct PosLookup : Lookup
 };
 
 typedef OffsetListOf<PosLookup> PosLookupList;
-ASSERT_SIZE (PosLookupList, 2);
 
 /*
  * GPOS
@@ -1592,8 +1595,9 @@ struct GPOS : GSUBGPOS
     OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
     return list.sanitize (context, this);
   }
+  public:
+  DEFINE_SIZE_STATIC (10);
 };
-ASSERT_SIZE (GPOS, 10);
 
 
 /* Out-of-class implementation for methods recursing */
diff --git a/src/hb-ot-layout-gsub-private.hh b/src/hb-ot-layout-gsub-private.hh
index 558540927..4a464b631 100644
--- a/src/hb-ot-layout-gsub-private.hh
+++ b/src/hb-ot-layout-gsub-private.hh
@@ -71,8 +71,9 @@ struct SingleSubstFormat1
 					 * beginning of Substitution table */
   SHORT		deltaGlyphID;		/* Add to original GlyphID to get
 					 * substitute GlyphID */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (SingleSubstFormat1, 6);
 
 struct SingleSubstFormat2
 {
@@ -115,8 +116,9 @@ struct SingleSubstFormat2
   ArrayOf<GlyphID>
 		substitute;		/* Array of substitute
 					 * GlyphIDs--ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (SingleSubstFormat2, 6);
 
 struct SingleSubst
 {
@@ -192,8 +194,9 @@ struct Sequence
   private:
   ArrayOf<GlyphID>
 		substitute;		/* String of GlyphIDs to substitute */
+  public:
+  DEFINE_SIZE_STATIC (2);
 };
-ASSERT_SIZE (Sequence, 2);
 
 struct MultipleSubstFormat1
 {
@@ -226,8 +229,9 @@ struct MultipleSubstFormat1
   OffsetArrayOf<Sequence>
 		sequence;		/* Array of Sequence tables
 					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (MultipleSubstFormat1, 6);
 
 struct MultipleSubst
 {
@@ -263,7 +267,6 @@ struct MultipleSubst
 
 typedef ArrayOf<GlyphID> AlternateSet;	/* Array of alternate GlyphIDs--in
 					 * arbitrary order */
-ASSERT_SIZE (AlternateSet, 2);
 
 struct AlternateSubstFormat1
 {
@@ -322,8 +325,9 @@ struct AlternateSubstFormat1
   OffsetArrayOf<AlternateSet>
 		alternateSet;		/* Array of AlternateSet tables
 					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (AlternateSubstFormat1, 6);
 
 struct AlternateSubst
 {
@@ -438,8 +442,9 @@ struct Ligature
 		component;		/* Array of component GlyphIDs--start
 					 * with the second  component--ordered
 					 * in writing direction */
+  public:
+  DEFINE_SIZE_STATIC (4);
 };
-ASSERT_SIZE (Ligature, 4);
 
 struct LigatureSet
 {
@@ -470,8 +475,9 @@ struct LigatureSet
   OffsetArrayOf<Ligature>
 		ligature;		/* Array LigatureSet tables
 					 * ordered by preference */
+  public:
+  DEFINE_SIZE_STATIC (2);
 };
-ASSERT_SIZE (LigatureSet, 2);
 
 struct LigatureSubstFormat1
 {
@@ -507,8 +513,9 @@ struct LigatureSubstFormat1
   OffsetArrayOf<LigatureSet>
 		ligatureSet;		/* Array LigatureSet tables
 					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (LigatureSubstFormat1, 6);
 
 struct LigatureSubst
 {
@@ -652,8 +659,9 @@ struct ReverseChainSingleSubstFormat1
   ArrayOf<GlyphID>
 		substituteX;		/* Array of substitute
 					 * GlyphIDs--ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_STATIC (10);
 };
-ASSERT_SIZE (ReverseChainSingleSubstFormat1, 10);
 
 struct ReverseChainSingleSubst
 {
@@ -865,7 +873,6 @@ struct SubstLookup : Lookup
 };
 
 typedef OffsetListOf<SubstLookup> SubstLookupList;
-ASSERT_SIZE (SubstLookupList, 2);
 
 /*
  * GSUB
@@ -890,8 +897,9 @@ struct GSUB : GSUBGPOS
     OffsetTo<SubstLookupList> &list = CastR<OffsetTo<SubstLookupList> > (lookupList);
     return list.sanitize (context, this);
   }
+  public:
+  DEFINE_SIZE_STATIC (10);
 };
-ASSERT_SIZE (GSUB, 10);
 
 
 /* Out-of-class implementation for methods recursing */
diff --git a/src/hb-ot-layout-gsubgpos-private.hh b/src/hb-ot-layout-gsubgpos-private.hh
index 0b59748ca..86285d17c 100644
--- a/src/hb-ot-layout-gsubgpos-private.hh
+++ b/src/hb-ot-layout-gsubgpos-private.hh
@@ -367,8 +367,9 @@ struct ContextFormat1
   OffsetArrayOf<RuleSet>
 		ruleSet;		/* Array of RuleSet tables
 					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (ContextFormat1, 6);
 
 
 struct ContextFormat2
@@ -414,8 +415,9 @@ struct ContextFormat2
   OffsetArrayOf<RuleSet>
 		ruleSet;		/* Array of RuleSet tables
 					 * ordered by class */
+  public:
+  DEFINE_SIZE_STATIC (8);
 };
-ASSERT_SIZE (ContextFormat2, 8);
 
 
 struct ContextFormat3
@@ -590,8 +592,9 @@ struct ChainRule
   ArrayOf<LookupRecord>
 		lookupX;		/* Array of LookupRecords--in
 					 * design order) */
+  public:
+  DEFINE_SIZE_STATIC (8);
 };
-ASSERT_SIZE (ChainRule, 8);
 
 struct ChainRuleSet
 {
@@ -617,8 +620,9 @@ struct ChainRuleSet
   OffsetArrayOf<ChainRule>
 		rule;			/* Array of ChainRule tables
 					 * ordered by preference */
+  public:
+  DEFINE_SIZE_STATIC (2);
 };
-ASSERT_SIZE (ChainRuleSet, 2);
 
 struct ChainContextFormat1
 {
@@ -654,8 +658,9 @@ struct ChainContextFormat1
   OffsetArrayOf<ChainRuleSet>
 		ruleSet;		/* Array of ChainRuleSet tables
 					 * ordered by Coverage Index */
+  public:
+  DEFINE_SIZE_STATIC (6);
 };
-ASSERT_SIZE (ChainContextFormat1, 6);
 
 struct ChainContextFormat2
 {
@@ -716,8 +721,9 @@ struct ChainContextFormat2
   OffsetArrayOf<ChainRuleSet>
 		ruleSet;		/* Array of ChainRuleSet tables
 					 * ordered by class */
+  public:
+  DEFINE_SIZE_STATIC (12);
 };
-ASSERT_SIZE (ChainContextFormat2, 12);
 
 struct ChainContextFormat3
 {
@@ -777,8 +783,9 @@ struct ChainContextFormat3
   ArrayOf<LookupRecord>
 		lookupX;		/* Array of LookupRecords--in
 					 * design order) */
+  public:
+  DEFINE_SIZE_STATIC (10);
 };
-ASSERT_SIZE (ChainContextFormat3, 10);
 
 struct ChainContext
 {
@@ -835,8 +842,9 @@ struct ExtensionFormat1
 					 * extension subtable). */
   ULONG		extensionOffset;	/* Offset to the extension subtable,
 					 * of lookup type subtable. */
+  public:
+  DEFINE_SIZE_STATIC (8);
 };
-ASSERT_SIZE (ExtensionFormat1, 8);
 
 struct Extension
 {
@@ -929,8 +937,9 @@ struct GSUBGPOS
 		featureList; 	/* FeatureList table */
   OffsetTo<LookupList>
 		lookupList; 	/* LookupList table */
+  public:
+  DEFINE_SIZE_STATIC (10);
 };
-ASSERT_SIZE (GSUBGPOS, 10);
 
 
 #endif /* HB_OT_LAYOUT_GSUBGPOS_PRIVATE_HH */
diff --git a/src/hb-private.h b/src/hb-private.h
index 3f8515bbb..8a323decf 100644
--- a/src/hb-private.h
+++ b/src/hb-private.h
@@ -83,8 +83,6 @@
 
 /* Misc */
 
-#define ASSERT_SIZE(_type, _size) ASSERT_STATIC (sizeof (_type) == (_size))
-
 
 #if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
 #define _HB_BOOLEAN_EXPR(expr) \