Index: src/InitTweak/FixInit.cc
===================================================================
--- src/InitTweak/FixInit.cc	(revision fd782b2be4d8d0e2485b8b387f34d18a1f6b3b52)
+++ src/InitTweak/FixInit.cc	(revision 3c13c03a94ca1d4baa7d03b64383f9d28bb7901f)
@@ -391,6 +391,6 @@
 				CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *impCpCtorExpr->get_env() << std::endl; )
 				// xxx - need to handle tuple arguments
-				assert( ! arg->get_results().empty() );
-				Type * result = arg->get_results().front();
+				assert( arg->has_result() );
+				Type * result = arg->get_result();
 				if ( skipCopyConstruct( result ) ) continue; // skip certain non-copyable types
 				// type may involve type variables, so apply type substitution to get temporary variable's actual type
@@ -423,5 +423,7 @@
 			// level. Trying to pass that environment along.
 			callExpr->set_env( impCpCtorExpr->get_env()->clone() );
-			for ( Type * result : appExpr->get_results() ) {
+			Type * result = appExpr->get_result();
+			if ( ! result->isVoid() ) {
+				// need to flatten result type and construct each
 				result = result->clone();
 				impCpCtorExpr->get_env()->apply( result );
@@ -479,8 +481,8 @@
 				// know the result type of the assignment is the type of the LHS (minus the pointer), so
 				// add that onto the assignment expression so that later steps have the necessary information
-				assign->add_result( returnDecl->get_type()->clone() );
+				assign->set_result( returnDecl->get_type()->clone() );
 
 				Expression * retExpr = new CommaExpr( assign, new VariableExpr( returnDecl ) );
-				if ( callExpr->get_results().front()->get_isLvalue() ) {
+				if ( callExpr->get_result()->get_isLvalue() ) {
 					// lvalue returning functions are funny. Lvalue.cc inserts a *? in front of any lvalue returning
 					// non-intrinsic function. Add an AddressExpr to the call to negate the derefence and change the
@@ -500,5 +502,5 @@
 					UntypedExpr * deref = new UntypedExpr( new NameExpr( "*?" ) );
 					deref->get_args().push_back( retExpr );
-					deref->add_result( resultType );
+					deref->set_result( resultType );
 					retExpr = deref;
 				} // if
@@ -939,6 +941,6 @@
 		Expression * FixCtorExprs::mutate( ConstructorExpr * ctorExpr ) {
 			static UniqueName tempNamer( "_tmp_ctor_expr" );
-			assert( ctorExpr->get_results().size() == 1 );
-			ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, nullptr, ctorExpr->get_results().front()->clone(), nullptr );
+			assert( ctorExpr->has_result() && ctorExpr->get_result()->size() == 1 );
+			ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, nullptr, ctorExpr->get_result()->clone(), nullptr );
 			addDeclaration( tmp );
 
@@ -952,5 +954,5 @@
 			assign->get_args().push_back( new VariableExpr( tmp ) );
 			assign->get_args().push_back( firstArg );
-			cloneAll( ctorExpr->get_results(), assign->get_results() );
+			assign->set_result( ctorExpr->get_result()->clone() );
 			firstArg = assign;
 
Index: src/InitTweak/InitTweak.cc
===================================================================
--- src/InitTweak/InitTweak.cc	(revision fd782b2be4d8d0e2485b8b387f34d18a1f6b3b52)
+++ src/InitTweak/InitTweak.cc	(revision 3c13c03a94ca1d4baa7d03b64383f9d28bb7901f)
@@ -340,6 +340,5 @@
 		return allofCtorDtor( stmt, []( Expression * callExpr ){
 			if ( ApplicationExpr * appExpr = isIntrinsicCallExpr( callExpr ) ) {
-				assert( ! appExpr->get_function()->get_results().empty() );
-				FunctionType *funcType = GenPoly::getFunctionType( appExpr->get_function()->get_results().front() );
+				FunctionType *funcType = GenPoly::getFunctionType( appExpr->get_function()->get_result() );
 				assert( funcType );
 				return funcType->get_parameters().size() == 1;