From f62a8cb61b443f6b5b91afe7ee7df541c6d2b2b7 Mon Sep 17 00:00:00 2001
From: Loki McKay <lokimckay@gmail.com>
Date: Sun, 19 May 2024 12:18:52 +1000
Subject: [PATCH] Add WithBaseField example to traits.rs (#715)

---
 godot-core/src/obj/traits.rs | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/godot-core/src/obj/traits.rs b/godot-core/src/obj/traits.rs
index 0888efc89..5c05bf39f 100644
--- a/godot-core/src/obj/traits.rs
+++ b/godot-core/src/obj/traits.rs
@@ -210,6 +210,24 @@ pub trait IndexEnum: EngineEnum {
 /// Trait that's implemented for user-defined classes that provide a `Base<T>` field.
 ///
 /// Gives direct access to the containing `Gd<Self>` from `Self`.
+///
+/// # Using WithBaseField as a bound
+///
+/// In order to call `self.base()` or `self.base_mut()` within a trait or on a type you define, the type of `Self::Base` must be specified via `WithBaseField<Base = T>`
+///
+/// E.g.
+///
+/// ```no_run
+/// # use godot::prelude::*;
+/// # use godot::obj::WithBaseField;
+/// fn some_fn<T>(value: &T)
+/// where
+///     T: WithBaseField<Base = Node3D>,
+/// {
+///     let base = value.base();
+/// }
+/// ```
+///
 // Possible alternative for builder APIs, although even less ergonomic: Base<T> could be Base<T, Self> and return Gd<Self>.
 #[diagnostic::on_unimplemented(
     message = "Class `{Self}` requires a `Base<T>` field",