Index: src/Common/PassVisitor.h
===================================================================
--- src/Common/PassVisitor.h	(revision ba915fb57763ae661ddfbc000c81dde9a5ae0003)
+++ src/Common/PassVisitor.h	(revision d24d4e166c6a6516f309efbac59c59da18c7169f)
@@ -26,5 +26,5 @@
 //                          stmtsToAddBefore or stmtsToAddAfter respectively.
 // | WithShortCircuiting  - provides the ability to skip visiting child nodes; set visit_children to false in pre{visit,mutate} to skip visiting children
-// | WithScopes           - provides the ability to save/restore data like a LIFO stack; to save, call GuardValue with the variable to save, the variable
+// | WithGuards           - provides the ability to save/restore data like a LIFO stack; to save, call GuardValue with the variable to save, the variable
 //                          will automatically be restored to its previous value after the corresponding postvisit/postmutate teminates.
 //-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
@@ -32,5 +32,4 @@
 class PassVisitor final : public Visitor, public Mutator {
 public:
-	PassVisitor() = default;
 
 	template< typename... Args >
@@ -283,5 +282,5 @@
 
 public:
-	TypeSubstitution * env;
+	TypeSubstitution * env = nullptr;
 };
 
@@ -295,4 +294,15 @@
 	std::list< Statement* > stmtsToAddAfter;
 };
+
+class WithDeclsToAdd {
+protected:
+	WithDeclsToAdd() = default;
+	~WithDeclsToAdd() = default;
+
+public:
+	std::list< Declaration* > declsToAddBefore;
+	std::list< Declaration* > declsToAddAfter;
+};
+
 class WithShortCircuiting {
 protected:
@@ -304,8 +314,8 @@
 };
 
-class WithScopes {
-protected:
-	WithScopes() = default;
-	~WithScopes() = default;
+class WithGuards {
+protected:
+	WithGuards() = default;
+	~WithGuards() = default;
 
 public:
@@ -319,7 +329,15 @@
 	}
 
+	template< typename T >
+	void GuardScope( T& val ) {
+		val.beginScope();
+		at_cleanup( []( void * val ) {
+			static_cast< T * >( val )->endScope();
+		}, static_cast< void * >( & val ) );
+	}
+
 	template< typename Func >
-	void GuardAction( Func&& func ) {
-		at_cleanup( std::forward<Func>( func ) );
+	void GuardAction( Func func ) {
+		at_cleanup( [func](__attribute__((unused)) void *) { func(); }, nullptr );
 	}
 };
@@ -328,9 +346,9 @@
 class WithVisitorRef {
 protected:
-	WithVisitorRef() = default;
-	~WithVisitorRef() = default;
-
-public:
-	PassVisitor<pass_type> * const visitor;
+	WithVisitorRef() {}
+	~WithVisitorRef() {}
+
+public:
+	PassVisitor<pass_type> * const visitor = nullptr;
 };
 
Index: src/Common/PassVisitor.impl.h
===================================================================
--- src/Common/PassVisitor.impl.h	(revision ba915fb57763ae661ddfbc000c81dde9a5ae0003)
+++ src/Common/PassVisitor.impl.h	(revision d24d4e166c6a6516f309efbac59c59da18c7169f)
@@ -68,5 +68,5 @@
 	for ( std::list< Declaration* >::iterator i = decls.begin(); ; ++i ) {
 		// splice in new declarations after previous decl
-		if ( !empty( afterDecls ) ) { decls.splice( i, *afterDecls ); }	
+		if ( !empty( afterDecls ) ) { decls.splice( i, *afterDecls ); }
 
 		if ( i == decls.end() ) break;
@@ -88,5 +88,5 @@
 	for ( std::list< Declaration* >::iterator i = decls.begin(); ; ++i ) {
 		// splice in new declarations after previous decl
-		if ( !empty( afterDecls ) ) { decls.splice( i, *afterDecls ); }	
+		if ( !empty( afterDecls ) ) { decls.splice( i, *afterDecls ); }
 
 		if ( i == decls.end() ) break;
@@ -181,5 +181,5 @@
 Statement * PassVisitor< pass_type >::visitStatement( Statement * stmt ) {
 	return handleStatement( stmt, [this]( Statement * stmt ) {
-		maybeAccept( stmt, *this ); 
+		maybeAccept( stmt, *this );
 		return stmt;
 	});
@@ -212,5 +212,5 @@
 		expr->accept( *this );
 		return expr;
-	});		
+	});
 }