Implement `String::resize()`

binding_generator.py

@@ -366,6 +366,7 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
     if class_name == "String":
         result.append("#include <godot_cpp/variant/char_string.hpp>")
         result.append("#include <godot_cpp/variant/char_utils.hpp>")
+        result.append("#include <godot_cpp/classes/global_constants.hpp>")
 
     if class_name == "PackedStringArray":
         result.append("#include <godot_cpp/variant/string.hpp>")
@@ -552,6 +553,7 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
         result.append("\tChar32String utf32() const;")
         result.append("\tCharWideString wide_string() const;")
         result.append("\tstatic String num_real(double p_num, bool p_trailing = true);")
+        result.append("\tError resize(int p_size);")
 
     if "members" in builtin_api:
         for member in builtin_api["members"]:

gdextension/gdextension_interface.h

@@ -1526,6 +1526,25 @@ typedef void (*GDExtensionInterfaceStringOperatorPlusEqWcstr)(GDExtensionStringP
  */
 typedef void (*GDExtensionInterfaceStringOperatorPlusEqC32str)(GDExtensionStringPtr p_self, const char32_t *p_b);
 
+/**
+ * @name string_resize
+ * @since 4.2
+ *
+ * Resizes the underlying string data to the given number of characters.
+ *
+ * Space needs to be allocated for the null terminating character ('\0') which
+ * also must be added manually, in order for all string functions to work correctly.
+ *
+ * Warning: This is an error-prone operation - only use it if there's no other
+ * efficient way to accomplish your goal.
+ *
+ * @param p_self A pointer to the String.
+ * @param p_resize The new length for the String.
+ *
+ * @return Error code signifying if the operation successful.
+ */
+typedef GDExtensionInt (*GDExtensionInterfaceStringResize)(GDExtensionStringPtr p_self, GDExtensionInt p_resize);
+
 /* INTERFACE: XMLParser Utilities */
 
 /**

include/godot_cpp/godot.hpp

@@ -123,6 +123,7 @@ extern "C" GDExtensionInterfaceStringOperatorPlusEqChar gdextension_interface_st
 extern "C" GDExtensionInterfaceStringOperatorPlusEqCstr gdextension_interface_string_operator_plus_eq_cstr;
 extern "C" GDExtensionInterfaceStringOperatorPlusEqWcstr gdextension_interface_string_operator_plus_eq_wcstr;
 extern "C" GDExtensionInterfaceStringOperatorPlusEqC32str gdextension_interface_string_operator_plus_eq_c32str;
+extern "C" GDExtensionInterfaceStringResize gdextension_interface_string_resize;
 extern "C" GDExtensionInterfaceXmlParserOpenBuffer gdextension_interface_xml_parser_open_buffer;
 extern "C" GDExtensionInterfaceFileAccessStoreBuffer gdextension_interface_file_access_store_buffer;
 extern "C" GDExtensionInterfaceFileAccessGetBuffer gdextension_interface_file_access_get_buffer;

src/godot.cpp

@@ -128,6 +128,7 @@ GDExtensionInterfaceStringOperatorPlusEqChar gdextension_interface_string_operat
 GDExtensionInterfaceStringOperatorPlusEqCstr gdextension_interface_string_operator_plus_eq_cstr = nullptr;
 GDExtensionInterfaceStringOperatorPlusEqWcstr gdextension_interface_string_operator_plus_eq_wcstr = nullptr;
 GDExtensionInterfaceStringOperatorPlusEqC32str gdextension_interface_string_operator_plus_eq_c32str = nullptr;
+GDExtensionInterfaceStringResize gdextension_interface_string_resize = nullptr;
 GDExtensionInterfaceXmlParserOpenBuffer gdextension_interface_xml_parser_open_buffer = nullptr;
 GDExtensionInterfaceFileAccessStoreBuffer gdextension_interface_file_access_store_buffer = nullptr;
 GDExtensionInterfaceFileAccessGetBuffer gdextension_interface_file_access_get_buffer = nullptr;
@@ -311,6 +312,7 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	LOAD_PROC_ADDRESS(string_operator_plus_eq_cstr, GDExtensionInterfaceStringOperatorPlusEqCstr);
 	LOAD_PROC_ADDRESS(string_operator_plus_eq_wcstr, GDExtensionInterfaceStringOperatorPlusEqWcstr);
 	LOAD_PROC_ADDRESS(string_operator_plus_eq_c32str, GDExtensionInterfaceStringOperatorPlusEqC32str);
+	LOAD_PROC_ADDRESS(string_resize, GDExtensionInterfaceStringResize);
 	LOAD_PROC_ADDRESS(xml_parser_open_buffer, GDExtensionInterfaceXmlParserOpenBuffer);
 	LOAD_PROC_ADDRESS(file_access_store_buffer, GDExtensionInterfaceFileAccessStoreBuffer);
 	LOAD_PROC_ADDRESS(file_access_get_buffer, GDExtensionInterfaceFileAccessGetBuffer);

src/variant/char_string.cpp

@@ -289,6 +289,10 @@ CharWideString String::wide_string() const {
 	return str;
 }
 
+Error String::resize(int p_size) {
+	return (Error)internal::gdextension_interface_string_resize(_native_ptr(), p_size);
+}
+
 String &String::operator=(const char *p_str) {
 	*this = String(p_str);
 	return *this;

test/project/main.gd

@@ -86,6 +86,9 @@ func _ready():
 	assert_equal(example.test_string_is_fourty_two("blah"), false)
 	assert_equal(example.test_string_is_fourty_two("fourty two"), true)
 
+	# String::resize().
+	assert_equal(example.test_string_resize("What"), "What!?")
+
 	# PackedArray iterators
 	assert_equal(example.test_vector_ops(), 105)
 

test/src/example.cpp

@@ -139,6 +139,7 @@ void Example::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("test_string_ops"), &Example::test_string_ops);
 	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_string_resize"), &Example::test_string_resize);
 	ClassDB::bind_method(D_METHOD("test_vector_ops"), &Example::test_vector_ops);
 
 	ClassDB::bind_method(D_METHOD("test_bitfield", "flags"), &Example::test_bitfield);
@@ -304,6 +305,16 @@ bool Example::test_string_is_fourty_two(const String &p_string) const {
 	return strcmp(p_string.utf8().ptr(), "fourty two") == 0;
 }
 
+String Example::test_string_resize(String p_string) const {
+	int orig_len = p_string.length();
+	p_string.resize(orig_len + 3);
+	char32_t *data = p_string.ptrw();
+	data[orig_len + 0] = '!';
+	data[orig_len + 1] = '?';
+	data[orig_len + 2] = '\0';
+	return p_string;
+}
+
 int Example::test_vector_ops() const {
 	PackedInt32Array arr;
 	arr.push_back(10);

test/src/example.h

@@ -118,6 +118,7 @@ public:
 	String test_string_ops() const;
 	String test_str_utility() const;
 	bool test_string_is_fourty_two(const String &p_str) const;
+	String test_string_resize(String p_original) const;
 	int test_vector_ops() const;
 
 	BitField<Flags> test_bitfield(BitField<Flags> flags);