Index: src/InitTweak/InitTweak.cc
===================================================================
--- src/InitTweak/InitTweak.cc	(revision 0a6aad4aa53e854b5b0a43ec60d74add61bb90a4)
+++ src/InitTweak/InitTweak.cc	(revision c5f3c68c3e861030ba705e8dae111f3bea0870ed)
@@ -539,48 +539,37 @@
 	}
 
-	class ConstExprChecker : public Visitor {
-	public:
-		ConstExprChecker() : isConstExpr( true ) {}
-
-		using Visitor::visit;
-
-		virtual void visit( ApplicationExpr * ) { isConstExpr = false; }
-		virtual void visit( UntypedExpr * ) { isConstExpr = false; }
-		virtual void visit( NameExpr * ) { isConstExpr = false; }
-		// virtual void visit( CastExpr *castExpr ) { isConstExpr = false; }
-		virtual void visit( AddressExpr *addressExpr ) {
+	struct ConstExprChecker : public WithShortCircuiting {
+		// most expressions are not const expr
+		void previsit( Expression * ) { isConstExpr = false; visit_children = false; }
+
+		void previsit( AddressExpr *addressExpr ) {
+			visit_children = false;
+
 			// address of a variable or member expression is constexpr
 			Expression * arg = addressExpr->get_arg();
 			if ( ! dynamic_cast< NameExpr * >( arg) && ! dynamic_cast< VariableExpr * >( arg ) && ! dynamic_cast< MemberExpr * >( arg ) && ! dynamic_cast< UntypedMemberExpr * >( arg ) ) isConstExpr = false;
 		}
-		virtual void visit( UntypedMemberExpr * ) { isConstExpr = false; }
-		virtual void visit( MemberExpr * ) { isConstExpr = false; }
-		virtual void visit( VariableExpr * ) { isConstExpr = false; }
-		// these might be okay?
-		// virtual void visit( SizeofExpr *sizeofExpr );
-		// virtual void visit( AlignofExpr *alignofExpr );
-		// virtual void visit( UntypedOffsetofExpr *offsetofExpr );
-		// virtual void visit( OffsetofExpr *offsetofExpr );
-		// virtual void visit( OffsetPackExpr *offsetPackExpr );
-		// virtual void visit( AttrExpr *attrExpr );
-		// virtual void visit( CommaExpr *commaExpr );
-		// virtual void visit( LogicalExpr *logicalExpr );
-		// virtual void visit( ConditionalExpr *conditionalExpr );
-		virtual void visit( TypeExpr * ) { isConstExpr = false; }
-		virtual void visit( AsmExpr * ) { isConstExpr = false; }
-		virtual void visit( UntypedValofExpr * ) { isConstExpr = false; }
-		virtual void visit( CompoundLiteralExpr * ) { isConstExpr = false; }
-		virtual void visit( UntypedTupleExpr * ) { isConstExpr = false; }
-		virtual void visit( TupleExpr * ) { isConstExpr = false; }
-		virtual void visit( TupleAssignExpr * ) { isConstExpr = false; }
-
-		bool isConstExpr;
+
+		// these expressions may be const expr, depending on their children
+		void previsit( SizeofExpr * ) {}
+		void previsit( AlignofExpr * ) {}
+		void previsit( UntypedOffsetofExpr * ) {}
+		void previsit( OffsetofExpr * ) {}
+		void previsit( OffsetPackExpr * ) {}
+		void previsit( AttrExpr * ) {}
+		void previsit( CommaExpr * ) {}
+		void previsit( LogicalExpr * ) {}
+		void previsit( ConditionalExpr * ) {}
+		void previsit( CastExpr * ) {}
+		void previsit( ConstantExpr * ) {}
+
+		bool isConstExpr = true;
 	};
 
 	bool isConstExpr( Expression * expr ) {
 		if ( expr ) {
-			ConstExprChecker checker;
+			PassVisitor<ConstExprChecker> checker;
 			expr->accept( checker );
-			return checker.isConstExpr;
+			return checker.pass.isConstExpr;
 		}
 		return true;
@@ -589,7 +578,7 @@
 	bool isConstExpr( Initializer * init ) {
 		if ( init ) {
-			ConstExprChecker checker;
+			PassVisitor<ConstExprChecker> checker;
 			init->accept( checker );
-			return checker.isConstExpr;
+			return checker.pass.isConstExpr;
 		} // if
 		// for all intents and purposes, no initializer means const expr