Merge pull request #1155 from dsnopek/callable-mp

Implement `callable_mp()` and `callable_mp_static()`

10 files changed, 545 insertions, 0 deletions

diff --git a/gdextension/gdextension_interface.h b/gdextension/gdextension_interface.h
index eb4fdc5..48cb288 100644
--- a/gdextension/gdextension_interface.h
+++ b/gdextension/gdextension_interface.h
@@ -379,6 +379,47 @@ typedef struct {
 	GDExtensionVariantPtr *default_arguments;
 } GDExtensionClassMethodInfo;
 
+typedef void (*GDExtensionCallableCustomCall)(void *callable_userdata, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argument_count, GDExtensionVariantPtr r_return, GDExtensionCallError *r_error);
+typedef GDExtensionBool (*GDExtensionCallableCustomIsValid)(void *callable_userdata);
+typedef void (*GDExtensionCallableCustomFree)(void *callable_userdata);
+
+typedef uint32_t (*GDExtensionCallableCustomHash)(void *callable_userdata);
+typedef GDExtensionBool (*GDExtensionCallableCustomEqual)(void *callable_userdata_a, void *callable_userdata_b);
+typedef GDExtensionBool (*GDExtensionCallableCustomLessThan)(void *callable_userdata_a, void *callable_userdata_b);
+
+typedef void (*GDExtensionCallableCustomToString)(void *callable_userdata, GDExtensionBool *r_is_valid, GDExtensionStringPtr r_out);
+
+typedef struct {
+	/* Only `call_func` and `token` are strictly required, however, `object` should be passed if its not a static method.
+	 *
+	 * `token` should point to an address that uniquely identifies the GDExtension (for example, the
+	 * `GDExtensionClassLibraryPtr` passed to the entry symbol function.
+	 *
+	 * `hash_func`, `equal_func`, and `less_than_func` are optional. If not provided both `call_func` and
+	 * `callable_userdata` together are used as the identity of the callable for hashing and comparison purposes.
+	 *
+	 * The hash returned by `hash_func` is cached, `hash_func` will not be called more than once per callable.
+	 *
+	 * `is_valid_func` is necessary if the validity of the callable can change before destruction.
+	 *
+	 * `free_func` is necessary if `callable_userdata` needs to be cleaned up when the callable is freed.
+	 */
+	void *callable_userdata;
+	void *token;
+
+	GDExtensionObjectPtr object;
+
+	GDExtensionCallableCustomCall call_func;
+	GDExtensionCallableCustomIsValid is_valid_func;
+	GDExtensionCallableCustomFree free_func;
+
+	GDExtensionCallableCustomHash hash_func;
+	GDExtensionCallableCustomEqual equal_func;
+	GDExtensionCallableCustomLessThan less_than_func;
+
+	GDExtensionCallableCustomToString to_string_func;
+} GDExtensionCallableCustomInfo;
+
 /* SCRIPT INSTANCE EXTENSION */
 
 typedef void *GDExtensionScriptInstanceDataPtr; // Pointer to custom ScriptInstance native implementation.
@@ -2262,6 +2303,34 @@ typedef void (*GDExtensionInterfacePlaceHolderScriptInstanceUpdate)(GDExtensionS
  */
 typedef GDExtensionScriptInstanceDataPtr (*GDExtensionInterfaceObjectGetScriptInstance)(GDExtensionConstObjectPtr p_object, GDExtensionObjectPtr p_language);
 
+/* INTERFACE: Callable */
+
+/**
+ * @name callable_custom_create
+ * @since 4.2
+ *
+ * Creates a custom Callable object from a function pointer.
+ *
+ * Provided struct can be safely freed once the function returns.
+ *
+ * @param r_callable A pointer that will receive the new Callable.
+ * @param p_callable_custom_info The info required to construct a Callable.
+ */
+typedef void (*GDExtensionInterfaceCallableCustomCreate)(GDExtensionUninitializedTypePtr r_callable, GDExtensionCallableCustomInfo *p_callable_custom_info);
+
+/**
+ * @name callable_custom_get_userdata
+ * @since 4.2
+ *
+ * Retrieves the userdata pointer from a custom Callable.
+ *
+ * If the Callable is not a custom Callable or the token does not match the one provided to callable_custom_create() via GDExtensionCallableCustomInfo then NULL will be returned.
+ *
+ * @param p_callable A pointer to a Callable.
+ * @param p_token A pointer to an address that uniquely identifies the GDExtension.
+ */
+typedef void *(*GDExtensionInterfaceCallableCustomGetUserData)(GDExtensionConstTypePtr p_callable, void *p_token);
+
 /* INTERFACE: ClassDB */
 
 /**
diff --git a/include/godot_cpp/core/binder_common.hpp b/include/godot_cpp/core/binder_common.hpp
index 09da62b..a51e15e 100644
--- a/include/godot_cpp/core/binder_common.hpp
+++ b/include/godot_cpp/core/binder_common.hpp
@@ -277,6 +277,60 @@ void call_with_variant_args_retc_helper(T *p_instance, R (T::*p_method)(P...) co
 }
 
 template <class T, class... P>
+void call_with_variant_args(T *p_instance, void (T::*p_method)(P...), const Variant **p_args, int p_argcount, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_helper<T, P...>(p_instance, p_method, p_args, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class T, class R, class... P>
+void call_with_variant_args_ret(T *p_instance, R (T::*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_ret_helper<T, R, P...>(p_instance, p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class T, class R, class... P>
+void call_with_variant_args_retc(T *p_instance, R (T::*p_method)(P...) const, const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_retc_helper<T, R, P...>(p_instance, p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class T, class... P>
 void call_with_variant_args_dv(T *p_instance, void (T::*p_method)(P...), const GDExtensionConstVariantPtr *p_args, int p_argcount, GDExtensionCallError &r_error, const std::vector<Variant> &default_values) {
 #ifdef DEBUG_ENABLED
 	if ((size_t)p_argcount > sizeof...(P)) {
@@ -538,6 +592,42 @@ void call_with_ptr_args_static_method(void (*p_method)(P...), const GDExtensionC
 	call_with_ptr_args_static_method_helper<P...>(p_method, p_args, BuildIndexSequence<sizeof...(P)>{});
 }
 
+template <class R, class... P>
+void call_with_variant_args_static_ret(R (*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_static_ret<R, P...>(p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class... P>
+void call_with_variant_args_static_ret(void (*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_static<P...>(p_method, p_args, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
 template <class R, class... P, size_t... Is>
 void call_with_variant_args_static_ret(R (*p_method)(P...), const Variant **p_args, Variant &r_ret, GDExtensionCallError &r_error, IndexSequence<Is...>) {
 	r_error.error = GDEXTENSION_CALL_OK;
diff --git a/include/godot_cpp/core/class_db.hpp b/include/godot_cpp/core/class_db.hpp
index af81037..c974fa4 100644
--- a/include/godot_cpp/core/class_db.hpp
+++ b/include/godot_cpp/core/class_db.hpp
@@ -40,6 +40,10 @@
 
 #include <godot_cpp/classes/class_db_singleton.hpp>
 
+// Makes callable_mp readily available in all classes connecting signals.
+// Needs to come after method_bind and object have been included.
+#include <godot_cpp/variant/callable_method_pointer.hpp>
+
 #include <list>
 #include <set>
 #include <string>
diff --git a/include/godot_cpp/godot.hpp b/include/godot_cpp/godot.hpp
index a3fae75..4561a75 100644
--- a/include/godot_cpp/godot.hpp
+++ b/include/godot_cpp/godot.hpp
@@ -164,6 +164,7 @@ extern "C" GDExtensionInterfaceObjectGetClassName gdextension_interface_object_g
 extern "C" GDExtensionInterfaceObjectCastTo gdextension_interface_object_cast_to;
 extern "C" GDExtensionInterfaceObjectGetInstanceFromId gdextension_interface_object_get_instance_from_id;
 extern "C" GDExtensionInterfaceObjectGetInstanceId gdextension_interface_object_get_instance_id;
+extern "C" GDExtensionInterfaceCallableCustomCreate gdextension_interface_callable_custom_create;
 extern "C" GDExtensionInterfaceRefGetObject gdextension_interface_ref_get_object;
 extern "C" GDExtensionInterfaceRefSetObject gdextension_interface_ref_set_object;
 extern "C" GDExtensionInterfaceScriptInstanceCreate2 gdextension_interface_script_instance_create2;
diff --git a/include/godot_cpp/variant/callable_method_pointer.hpp b/include/godot_cpp/variant/callable_method_pointer.hpp
new file mode 100644
index 0000000..bd31ea1
--- /dev/null
+++ b/include/godot_cpp/variant/callable_method_pointer.hpp
@@ -0,0 +1,215 @@
+/**************************************************************************/
+/*  callable_method_pointer.hpp                                           */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef GODOT_CALLABLE_METHOD_POINTER_HPP
+#define GODOT_CALLABLE_METHOD_POINTER_HPP
+
+#include <godot_cpp/core/binder_common.hpp>
+#include <godot_cpp/variant/variant.hpp>
+
+namespace godot {
+
+class CallableCustomMethodPointerBase {
+public:
+	virtual Object *get_object() const = 0;
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const = 0;
+};
+
+namespace internal {
+
+Callable create_custom_callable(CallableCustomMethodPointerBase *p_callable_method_pointer);
+
+} // namespace internal
+
+//
+// No return value.
+//
+
+template <class T, class... P>
+class CallableCustomMethodPointer : public CallableCustomMethodPointerBase {
+	T *instance;
+	void (T::*method)(P...);
+
+public:
+	virtual Object *get_object() const override {
+		return instance;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args(instance, method, p_arguments, p_argcount, r_call_error);
+	}
+
+	CallableCustomMethodPointer(T *p_instance, void (T::*p_method)(P...)) {
+		instance = p_instance;
+		method = p_method;
+	}
+};
+
+template <class T, class... P>
+Callable create_custom_callable_function_pointer(T *p_instance, void (T::*p_method)(P...)) {
+	typedef CallableCustomMethodPointer<T, P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// With return value.
+//
+
+template <class T, class R, class... P>
+class CallableCustomMethodPointerRet : public CallableCustomMethodPointerBase {
+	T *instance;
+	R(T::*method)
+	(P...);
+
+public:
+	virtual Object *get_object() const override {
+		return instance;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args_ret(instance, method, p_arguments, p_argcount, r_return_value, r_call_error);
+	}
+
+	CallableCustomMethodPointerRet(T *p_instance, R (T::*p_method)(P...)) {
+		instance = p_instance;
+		method = p_method;
+	}
+};
+
+template <class T, class R, class... P>
+Callable create_custom_callable_function_pointer(T *p_instance, R (T::*p_method)(P...)) {
+	typedef CallableCustomMethodPointerRet<T, R, P...> CCMP; // Messes with memnew otherwise.
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// Const with return value.
+//
+
+template <class T, class R, class... P>
+class CallableCustomMethodPointerRetC : public CallableCustomMethodPointerBase {
+	T *instance;
+	R(T::*method)
+	(P...) const;
+
+public:
+	virtual Object *get_object() const override {
+		return instance;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args_retc(instance, method, p_arguments, p_argcount, r_return_value, r_call_error);
+	}
+
+	CallableCustomMethodPointerRetC(const T *p_instance, R (T::*p_method)(P...) const) {
+		instance = const_cast<T *>(p_instance);
+		method = p_method;
+	}
+};
+
+template <class T, class R, class... P>
+Callable create_custom_callable_function_pointer(const T *p_instance, R (T::*p_method)(P...) const) {
+	typedef CallableCustomMethodPointerRetC<T, R, P...> CCMP; // Messes with memnew otherwise.
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// Static method with no return value.
+//
+
+template <class... P>
+class CallableCustomStaticMethodPointer : public CallableCustomMethodPointerBase {
+	void (*method)(P...);
+
+public:
+	virtual Object *get_object() const override {
+		return nullptr;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args_static_ret(method, p_arguments, p_argcount, r_return_value, r_call_error);
+		r_return_value = Variant();
+	}
+
+	CallableCustomStaticMethodPointer(void (*p_method)(P...)) {
+		method = p_method;
+	}
+};
+
+template <class... P>
+Callable create_custom_callable_static_function_pointer(void (*p_method)(P...)) {
+	typedef CallableCustomStaticMethodPointer<P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// Static method with return value.
+//
+
+template <class R, class... P>
+class CallableCustomStaticMethodPointerRet : public CallableCustomMethodPointerBase {
+	R(*method)
+	(P...);
+
+public:
+	virtual Object *get_object() const override {
+		return nullptr;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args_static_ret(method, p_arguments, p_argcount, r_return_value, r_call_error);
+	}
+
+	CallableCustomStaticMethodPointerRet(R (*p_method)(P...)) {
+		method = p_method;
+	}
+};
+
+template <class R, class... P>
+Callable create_custom_callable_static_function_pointer(R (*p_method)(P...)) {
+	typedef CallableCustomStaticMethodPointerRet<R, P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// The API:
+//
+
+#define callable_mp(I, M) ::godot::create_custom_callable_function_pointer(I, M)
+#define callable_mp_static(M) ::godot::create_custom_callable_static_function_pointer(M)
+
+} // namespace godot
+
+#endif // GODOT_CALLABLE_METHOD_POINTER_HPP
diff --git a/src/godot.cpp b/src/godot.cpp
index 0671221..05413ff 100644
--- a/src/godot.cpp
+++ b/src/godot.cpp
@@ -170,6 +170,7 @@ GDExtensionInterfaceObjectGetClassName gdextension_interface_object_get_class_na
 GDExtensionInterfaceObjectCastTo gdextension_interface_object_cast_to = nullptr;
 GDExtensionInterfaceObjectGetInstanceFromId gdextension_interface_object_get_instance_from_id = nullptr;
 GDExtensionInterfaceObjectGetInstanceId gdextension_interface_object_get_instance_id = nullptr;
+GDExtensionInterfaceCallableCustomCreate gdextension_interface_callable_custom_create = nullptr;
 GDExtensionInterfaceRefGetObject gdextension_interface_ref_get_object = nullptr;
 GDExtensionInterfaceRefSetObject gdextension_interface_ref_set_object = nullptr;
 GDExtensionInterfaceScriptInstanceCreate2 gdextension_interface_script_instance_create2 = nullptr;
@@ -386,6 +387,7 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	LOAD_PROC_ADDRESS(object_cast_to, GDExtensionInterfaceObjectCastTo);
 	LOAD_PROC_ADDRESS(object_get_instance_from_id, GDExtensionInterfaceObjectGetInstanceFromId);
 	LOAD_PROC_ADDRESS(object_get_instance_id, GDExtensionInterfaceObjectGetInstanceId);
+	LOAD_PROC_ADDRESS(callable_custom_create, GDExtensionInterfaceCallableCustomCreate);
 	LOAD_PROC_ADDRESS(ref_get_object, GDExtensionInterfaceRefGetObject);
 	LOAD_PROC_ADDRESS(ref_set_object, GDExtensionInterfaceRefSetObject);
 	LOAD_PROC_ADDRESS(script_instance_create2, GDExtensionInterfaceScriptInstanceCreate2);
diff --git a/src/variant/callable_method_pointer.cpp b/src/variant/callable_method_pointer.cpp
new file mode 100644
index 0000000..7934c73
--- /dev/null
+++ b/src/variant/callable_method_pointer.cpp
@@ -0,0 +1,66 @@
+/**************************************************************************/
+/*  callable_method_pointer.cpp                                           */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include <godot_cpp/variant/callable_method_pointer.hpp>
+
+//#include <godot_cpp/godot.hpp>
+
+namespace godot {
+
+static void call_custom_callable(void *userdata, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argument_count, GDExtensionVariantPtr r_return, GDExtensionCallError *r_error) {
+	CallableCustomMethodPointerBase *callable_method_pointer = (CallableCustomMethodPointerBase *)userdata;
+	callable_method_pointer->call((const Variant **)p_args, p_argument_count, *(Variant *)r_return, *r_error);
+}
+
+static void free_custom_callable(void *userdata) {
+	CallableCustomMethodPointerBase *callable_method_pointer = (CallableCustomMethodPointerBase *)userdata;
+	memdelete(callable_method_pointer);
+}
+
+namespace internal {
+
+Callable create_custom_callable(CallableCustomMethodPointerBase *p_callable_method_pointer) {
+	Object *object = p_callable_method_pointer->get_object();
+
+	GDExtensionCallableCustomInfo info = {};
+	info.callable_userdata = p_callable_method_pointer;
+	info.token = internal::token;
+	info.object = object != nullptr ? object->_owner : nullptr;
+	info.call_func = &call_custom_callable;
+	info.free_func = &free_custom_callable;
+
+	Callable callable;
+	::godot::internal::gdextension_interface_callable_custom_create(callable._native_ptr(), &info);
+	return callable;
+}
+
+} // namespace internal
+
+} // namespace godot
diff --git a/test/project/main.gd b/test/project/main.gd
index dbc60f8..f51ef3b 100644
--- a/test/project/main.gd
+++ b/test/project/main.gd
@@ -96,6 +96,28 @@ func _ready():
 	# String::resize().
 	assert_equal(example.test_string_resize("What"), "What!?")
 
+	# mp_callable() with void method.
+	var mp_callable: Callable = example.test_callable_mp()
+	mp_callable.call(example, "void", 36)
+	assert_equal(custom_signal_emitted, ["unbound_method1: Example - void", 36])
+
+	# mp_callable() with return value.
+	var mp_callable_ret: Callable = example.test_callable_mp_ret()
+	assert_equal(mp_callable_ret.call(example, "test", 77), "unbound_method2: Example - test - 77")
+
+	# mp_callable() with const method and return value.
+	var mp_callable_retc: Callable = example.test_callable_mp_retc()
+	assert_equal(mp_callable_retc.call(example, "const", 101), "unbound_method3: Example - const - 101")
+
+	# mp_callable_static() with void method.
+	var mp_callable_static: Callable = example.test_callable_mp_static()
+	mp_callable_static.call(example, "static", 83)
+	assert_equal(custom_signal_emitted, ["unbound_static_method1: Example - static", 83])
+
+	# mp_callable_static() with return value.
+	var mp_callable_static_ret: Callable = example.test_callable_mp_static_ret()
+	assert_equal(mp_callable_static_ret.call(example, "static-ret", 84), "unbound_static_method2: Example - static-ret - 84")
+
 	# PackedArray iterators
 	assert_equal(example.test_vector_ops(), 105)
 
diff --git a/test/src/example.cpp b/test/src/example.cpp
index 800f5ed..759cc4f 100644
--- a/test/src/example.cpp
+++ b/test/src/example.cpp
@@ -163,6 +163,12 @@ void Example::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("test_variant_call", "variant"), &Example::test_variant_call);
 
+	ClassDB::bind_method(D_METHOD("test_callable_mp"), &Example::test_callable_mp);
+	ClassDB::bind_method(D_METHOD("test_callable_mp_ret"), &Example::test_callable_mp_ret);
+	ClassDB::bind_method(D_METHOD("test_callable_mp_retc"), &Example::test_callable_mp_retc);
+	ClassDB::bind_method(D_METHOD("test_callable_mp_static"), &Example::test_callable_mp_static);
+	ClassDB::bind_method(D_METHOD("test_callable_mp_static_ret"), &Example::test_callable_mp_static_ret);
+
 	ClassDB::bind_method(D_METHOD("test_bitfield", "flags"), &Example::test_bitfield);
 
 	ClassDB::bind_method(D_METHOD("test_rpc", "value"), &Example::test_rpc);
@@ -349,6 +355,64 @@ int Example::test_vector_ops() const {
 	return ret;
 }
 
+Callable Example::test_callable_mp() {
+	return callable_mp(this, &Example::unbound_method1);
+}
+
+Callable Example::test_callable_mp_ret() {
+	return callable_mp(this, &Example::unbound_method2);
+}
+
+Callable Example::test_callable_mp_retc() const {
+	return callable_mp(this, &Example::unbound_method3);
+}
+
+Callable Example::test_callable_mp_static() const {
+	return callable_mp_static(&Example::unbound_static_method1);
+}
+
+Callable Example::test_callable_mp_static_ret() const {
+	return callable_mp_static(&Example::unbound_static_method2);
+}
+
+void Example::unbound_method1(Object *p_object, String p_string, int p_int) {
+	String test = "unbound_method1: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	emit_custom_signal(test, p_int);
+}
+
+String Example::unbound_method2(Object *p_object, String p_string, int p_int) {
+	String test = "unbound_method2: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	test += " - " + itos(p_int);
+	return test;
+}
+
+String Example::unbound_method3(Object *p_object, String p_string, int p_int) const {
+	String test = "unbound_method3: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	test += " - " + itos(p_int);
+	return test;
+}
+
+void Example::unbound_static_method1(Example *p_object, String p_string, int p_int) {
+	String test = "unbound_static_method1: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	p_object->emit_custom_signal(test, p_int);
+}
+
+String Example::unbound_static_method2(Object *p_object, String p_string, int p_int) {
+	String test = "unbound_static_method2: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	test += " - " + itos(p_int);
+	return test;
+}
+
 int Example::test_tarray_arg(const TypedArray<int64_t> &p_array) {
 	int sum = 0;
 	for (int i = 0; i < p_array.size(); i++) {
diff --git a/test/src/example.h b/test/src/example.h
index 354b7ba..4dfda23 100644
--- a/test/src/example.h
+++ b/test/src/example.h
@@ -138,6 +138,18 @@ public:
 
 	Variant test_variant_call(Variant p_variant);
 
+	Callable test_callable_mp();
+	Callable test_callable_mp_ret();
+	Callable test_callable_mp_retc() const;
+	Callable test_callable_mp_static() const;
+	Callable test_callable_mp_static_ret() const;
+
+	void unbound_method1(Object *p_object, String p_string, int p_int);
+	String unbound_method2(Object *p_object, String p_string, int p_int);
+	String unbound_method3(Object *p_object, String p_string, int p_int) const;
+	static void unbound_static_method1(Example *p_object, String p_string, int p_int);
+	static String unbound_static_method2(Object *p_object, String p_string, int p_int);
+
 	BitField<Flags> test_bitfield(BitField<Flags> flags);
 
 	// RPC