GDScript 2.0: Cannot use default values with typed arrays

[Kubulambula]

Godot version

4.0.alpha12

System information

Windows 10

Issue description

When using typed arrays as type for function arguments you cannot use default values.

For untyped arrays this is not an issue

func _ready():
	foo()
	bar()

# OK
func foo(optional_arr: Array = []):
	print(optional_arr) # []

# Also OK
func bar(optional_arr: Array = [1]):
	print(optional_arr) # [1]

But when using typed arrays it always results in error. Type of default value for parameter "optional_typed_arr" (Array) is not compatible with parameter type (Array[ *INSERT TYPE* ]).

func _ready():
	foo()
	bar()


func foo(optional_typed_arr: Array[Resource] = []):
	print(optional_typed_arr)


func bar(optional_typed_arr: Array[int] = [1]):
	print(optional_typed_arr)

Steps to reproduce

Just copy and paste the above example to any project

Minimal reproduction project

No response

[jonas-bischofberger]

The naive workaround to cast the default value with as leads to a silent crash as soon as the function is supposed to run (4.0.beta3, Windows 10):

extends Node

func foo(x: Array[int] = [] as Array[int]):
    pass

func _ready():
    foo()  # crashes without any output from debugger

[MaasTL]

A small addition: I'm using PackedStringArray but Error says Array[String]