[Packed*Array] Add support for initializer lists.

(cherry picked from commit 8c98a90f32)

binding_generator.py

@@ -375,6 +375,10 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
     if class_name == "PackedVector3Array":
         result.append("#include <godot_cpp/variant/vector3.hpp>")
 
+    if is_packed_array(class_name):
+        result.append("#include <godot_cpp/core/error_macros.hpp>")
+        result.append("#include <initializer_list>")
+
     if class_name == "Array":
         result.append("#include <godot_cpp/variant/array_helpers.hpp>")
 
@@ -692,6 +696,17 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
 	}
 """
         result.append(iterators.replace("$TYPE", return_type))
+        init_list = """
+    _FORCE_INLINE_ $CLASS(std::initializer_list<$TYPE> p_init) {
+		ERR_FAIL_COND(resize(p_init.size()) != 0);
+
+		size_t i = 0;
+		for (const $TYPE &element : p_init) {
+			set(i++, element);
+		}
+	}
+"""
+        result.append(init_list.replace("$TYPE", return_type).replace("$CLASS", class_name))
 
     if class_name == "Array":
         result.append("\tconst Variant &operator[](int64_t p_index) const;")

test/project/main.gd

@@ -91,6 +91,7 @@ func _ready():
 
 	# PackedArray iterators
 	assert_equal(example.test_vector_ops(), 105)
+	assert_equal(example.test_vector_init_list(), 105)
 
 	# Properties.
 	assert_equal(example.group_subgroup_custom_position, Vector2(0, 0))

test/src/example.cpp

@@ -148,6 +148,7 @@ void Example::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("test_str_utility"), &Example::test_str_utility);
 	ClassDB::bind_method(D_METHOD("test_string_is_fourty_two"), &Example::test_string_is_fourty_two);
 	ClassDB::bind_method(D_METHOD("test_vector_ops"), &Example::test_vector_ops);
+	ClassDB::bind_method(D_METHOD("test_vector_init_list"), &Example::test_vector_init_list);
 
 	ClassDB::bind_method(D_METHOD("test_object_cast_to_node", "object"), &Example::test_object_cast_to_node);
 	ClassDB::bind_method(D_METHOD("test_object_cast_to_control", "object"), &Example::test_object_cast_to_control);
@@ -339,6 +340,15 @@ int Example::test_vector_ops() const {
 	return ret;
 }
 
+int Example::test_vector_init_list() const {
+	PackedInt32Array arr = { 10, 20, 30, 45 };
+	int ret = 0;
+	for (const int32_t &E : arr) {
+		ret += E;
+	}
+	return ret;
+}
+
 int Example::test_tarray_arg(const TypedArray<int64_t> &p_array) {
 	int sum = 0;
 	for (int i = 0; i < p_array.size(); i++) {

test/src/example.h

@@ -127,6 +127,7 @@ public:
 	String test_str_utility() const;
 	bool test_string_is_fourty_two(const String &p_str) const;
 	int test_vector_ops() const;
+	int test_vector_init_list() const;
 
 	bool test_object_cast_to_node(Object *p_object) const;
 	bool test_object_cast_to_control(Object *p_object) const;