From db629211591f7ac8ab6d502d8bee3fce8b528312 Mon Sep 17 00:00:00 2001
From: Jules Bertholet <julesbertholet@quoi.xyz>
Date: Fri, 17 Nov 2023 19:54:37 -0500
Subject: [PATCH] Document behavior of `<dyn Any as Any>::type_id()`

See also #57893
---
 library/core/src/any.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/library/core/src/any.rs b/library/core/src/any.rs
index 8f5404d9713dd..22777fb078a26 100644
--- a/library/core/src/any.rs
+++ b/library/core/src/any.rs
@@ -115,6 +115,11 @@ use crate::intrinsics;
 pub trait Any: 'static {
     /// Gets the `TypeId` of `self`.
     ///
+    /// If called on a `dyn Any` trait object
+    /// (or a trait object of a subtrait of `Any`),
+    /// this returns the `TypeId` of the underlying
+    /// concrete type, not that of `dyn Any` itself.
+    ///
     /// # Examples
     ///
     /// ```