diff --git a/generate/codegen/gen_function.go b/generate/codegen/gen_function.go
index ea4f98c5..4434bcdc 100644
--- a/generate/codegen/gen_function.go
+++ b/generate/codegen/gen_function.go
@@ -175,6 +175,8 @@ func (f *Function) WriteGoCallCode(currentModule *modules.Module, cw *CodeWriter
 			sb.WriteString(cw.IndentStr + fmt.Sprintf("  (*C.%s)(unsafe.Pointer(&%s))", tt.CName(), p.GoName()))
 		case *typing.DispatchType:
 			sb.WriteString(cw.IndentStr + fmt.Sprintf("  (*C.%s)(unsafe.Pointer(&%s))", tt.CName(), p.GoName()))
+		case *typing.IDType:
+			sb.WriteString(cw.IndentStr + fmt.Sprintf("  %s.Ptr()", p.GoName()))
 		default:
 			sb.WriteString(cw.IndentStr + p.GoName())
 		}
@@ -196,6 +198,8 @@ func (f *Function) WriteGoCallCode(currentModule *modules.Module, cw *CodeWriter
 			cw.WriteLineF("return C.GoString(%s)", resultName)
 		case *typing.ProtocolType:
 			cw.WriteLineF("return %s{objc.ObjectFrom(%s)}", returnTypeStr, resultName)
+		case *typing.AliasType:
+			cw.WriteLineF("return *(*%s)(unsafe.Pointer(&%s))", returnTypeStr, resultName)
 		default:
 			cw.WriteLineF("return %s(%s)", returnTypeStr, resultName)
 		}
@@ -290,6 +294,7 @@ func (f *Function) WriteCSignature(currentModule *modules.Module, cw *CodeWriter
 	if cs, ok := rt.(hasCSignature); ok {
 		returnTypeStr = cs.CSignature()
 	}
+
 	if hasBlockParam(f.Parameters) {
 		cw.WriteLineF("// // TODO: %v not implemented (missing block param support)", f.Name)
 		return
diff --git a/generate/function.go b/generate/function.go
index ead33db1..b971a15e 100644
--- a/generate/function.go
+++ b/generate/function.go
@@ -45,6 +45,9 @@ var unhandledStructTypes = map[string]bool{
 	"CFUUIDBytes":                       true,
 	"dispatch_queue_t":                  true, // for return values, not parameters
 	"va_list":                           true,
+
+	"MTLIndirectCommandBufferExecutionRange": true,
+	"MTLPackedFloat3":                        true,
 }
 
 func (db *Generator) ToFunction(fw string, sym Symbol) *codegen.Function {
@@ -70,9 +73,8 @@ func (db *Generator) ToFunction(fw string, sym Symbol) *codegen.Function {
 		"CGPDFArrayGetName":                        true, // "const char * _Nullable *"
 		"CGPDFDictionaryGetName":                   true, // "const char *key, const char * _Nullable *"
 		"CGPDFScannerPopName":                      true, // "const char * _Nullable *"
-	}
-	if sym.Name != "MTLCreateSystemDefaultDevice" {
-		return nil
+
+		"MTLSizeMake": true, // duplicate symbol issue
 	}
 	if knownIssues[sym.Name] {
 		_, err := sym.Parse(db.Platform)
@@ -134,6 +136,12 @@ func (db *Generator) ToFunction(fw string, sym Symbol) *codegen.Function {
 		fmt.Printf("skipping %s because of unhandled struct type %s\n", sym.Name, fntyp.ReturnType.ObjcName())
 		return nil
 	}
+
+	// we (unfortuantely) don't handle array returns cleanly yet:
+	if _, ok := fntyp.ReturnType.(*typing.ArrayType); ok {
+		fmt.Printf("skipping %s because of array return type\n", sym.Name)
+		return nil
+	}
 	// populate return type
 	if fntyp.ReturnType != nil {
 		fn.ReturnType = fntyp.ReturnType
diff --git a/generate/typing/id_type.go b/generate/typing/id_type.go
index db30038e..25c7ff94 100644
--- a/generate/typing/id_type.go
+++ b/generate/typing/id_type.go
@@ -25,7 +25,7 @@ func (i *IDType) ObjcName() string {
 }
 
 func (i *IDType) CName() string {
-	return "id"
+	return "void *"
 }
 
 func (i *IDType) DeclareModule() *modules.Module {