Add InstanceId::lookup_validity()

godot-core/src/obj/gd.rs

@@ -209,9 +209,12 @@ impl<T: GodotClass> Gd<T> {
 
     /// ⚠️ Looks up the given instance ID and returns the associated object.
     ///
+    /// Corresponds to Godot's global function `instance_from_id()`.
+    ///
     /// # Panics
     /// If no such instance ID is registered, or if the dynamic type of the object behind that instance ID
     /// is not compatible with `T`.
+    #[doc(alias = "instance_from_id")]
     pub fn from_instance_id(instance_id: InstanceId) -> Self {
         Self::try_from_instance_id(instance_id).unwrap_or_else(|err| {
             panic!(

godot-core/src/obj/instance_id.rs

@@ -58,6 +58,17 @@ impl InstanceId {
         self.to_u64() & (1u64 << 63) != 0
     }
 
+    /// Dynamically checks if the instance behind the ID exists.
+    ///
+    /// Rather slow, involves engine round-trip plus object DB lookup. If you need the object, use
+    /// [`Gd::from_instance_id()`][crate::obj::Gd::from_instance_id] instead.
+    ///
+    /// This corresponds to Godot's global function `is_instance_id_valid()`.
+    #[doc(alias = "is_instance_id_valid")]
+    pub fn lookup_validity(self) -> bool {
+        crate::gen::utilities::is_instance_id_valid(self.to_i64())
+    }
+
     // Private: see rationale above
     pub(crate) fn to_u64(self) -> u64 {
         self.value.get()