Add Bounds<...> trait to check characteristics of GodotClass types

Author: Bromeon

godot-codegen/src/class_generator.rs

@@ -604,12 +604,18 @@ fn make_class(class: &Class, class_name: &TyName, ctx: &mut Context) -> Generate
         }
     };
 
-    let memory = if class_name.rust_ty == "Object" {
-        ident("DynamicRefCount")
+    let assoc_dyn_memory = if class_name.rust_ty == "Object" {
+        ident("MemDynamic")
     } else if class.is_refcounted {
-        ident("StaticRefCount")
+        ident("MemRefCounted")
     } else {
-        ident("ManualMemory")
+        ident("MemManual")
+    };
+
+    let assoc_memory = if class.is_refcounted {
+        ident("MemRefCounted")
+    } else {
+        ident("MemManual")
     };
 
     // mod re_export needed, because class should not appear inside the file module, and we can't re-export private struct as pub.
@@ -643,16 +649,19 @@ fn make_class(class: &Class, class_name: &TyName, ctx: &mut Context) -> Generate
                 #internal_methods
                 #constants
             }
-            unsafe impl crate::obj::GodotClass for #class_name {
+            impl crate::obj::GodotClass for #class_name {
                 type Base = #base_ty;
-                type Declarer = crate::obj::dom::EngineDomain;
-                type Mem = crate::obj::mem::#memory;
                 const INIT_LEVEL: Option<crate::init::InitLevel> = #init_level;
 
                 fn class_name() -> ClassName {
                     ClassName::from_ascii_cstr(#class_name_cstr)
                 }
             }
+            unsafe impl crate::obj::Bounds for #class_name {
+                type Memory = crate::obj::bounds::#assoc_memory;
+                type DynMemory = crate::obj::bounds::#assoc_dyn_memory;
+                type Declarer = crate::obj::bounds::DeclEngine;
+            }
             impl crate::obj::EngineClass for #class_name {
                 fn as_object_ptr(&self) -> sys::GDExtensionObjectPtr {
                     self.object_ptr

godot-core/src/builder/method.rs

@@ -117,7 +117,7 @@ macro_rules! impl_code_method {
 
                 $(
                     let $arg = <$Param as sys::GodotFfi>::from_sys(*args.offset(idx));
-                    // FIXME update refcount, e.g. Gd::ready() or T::Mem::maybe_inc_ref(&result);
+                    // FIXME update refcount, e.g. Gd::ready() or T::DynMemory::maybe_inc_ref(&result);
                     // possibly in from_sys() directly; what about from_sys_init() and from_{obj|str}_sys()?
                     idx += 1;
                 )*

godot-core/src/builtin/callable.rs

@@ -10,7 +10,8 @@ use godot_ffi as sys;
 use crate::builtin::meta::{impl_godot_as_self, GodotType, ToGodot};
 use crate::builtin::{inner, StringName, Variant, VariantArray};
 use crate::engine::Object;
-use crate::obj::mem::Memory;
+use crate::obj::bounds::DynMemory;
+use crate::obj::Bounds;
 use crate::obj::{Gd, GodotClass, InstanceId};
 use std::{fmt, ptr};
 use sys::{ffi_methods, GodotFfi};
@@ -202,7 +203,7 @@ impl Callable {
         // Increment refcount because we're getting a reference, and `InnerCallable::get_object` doesn't
         // increment the refcount.
         self.as_inner().get_object().map(|object| {
-            <Object as GodotClass>::Mem::maybe_inc_ref(&object.raw);
+            <Object as Bounds>::DynMemory::maybe_inc_ref(&object.raw);
             object
         })
     }

godot-core/src/engine/mod.rs

@@ -8,8 +8,7 @@
 //! Godot engine classes and methods.
 
 use crate::builtin::{GString, NodePath};
-use crate::obj::dom::EngineDomain;
-use crate::obj::{Gd, GodotClass, Inherits, InstanceId};
+use crate::obj::{bounds, Bounds, Gd, GodotClass, Inherits, InstanceId};
 use std::collections::HashSet;
 
 // Re-exports of generated symbols
@@ -115,7 +114,7 @@ impl NodeExt for Node {
 
 impl<U> NodeExt for Gd<U>
 where
-    U: GodotClass<Declarer = EngineDomain> + Inherits<Node>,
+    U: Bounds<Declarer = bounds::DeclEngine> + Inherits<Node>,
 {
     fn try_get_node_as<T>(&self, path: impl Into<NodePath>) -> Option<Gd<T>>
     where
@@ -163,7 +162,7 @@ pub(crate) fn object_ptr_from_id(instance_id: InstanceId) -> sys::GDExtensionObj
 
 pub(crate) fn construct_engine_object<T>() -> Gd<T>
 where
-    T: GodotClass<Declarer = EngineDomain>,
+    T: GodotClass + Bounds<Declarer = bounds::DeclEngine>,
 {
     // SAFETY: adhere to Godot API; valid class name and returned pointer is an object.
     unsafe {