std: Hide facade extension traits in docs

These traits are currently all just unstable parts of the facade which are
implementation details for primitives further up the facade. This may make it
more difficult to find what set of methods you get if only linking to libcore,
but for now that's also unstable behavior.

Closes #22025

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libcore/char.rs b/src/libcore/char.rs
index 010415b364a..ba9748eea71 100644
--- a/src/libcore/char.rs
+++ b/src/libcore/char.rs
@@ -139,6 +139,7 @@ pub fn from_digit(num: u32, radix: u32) -> Option<char> {
 // NB: the stabilization and documentation for this trait is in
 // unicode/char.rs, not here
 #[allow(missing_docs)] // docs in libunicode/u_char.rs
+#[doc(hidden)]
 pub trait CharExt {
     fn is_digit(self, radix: u32) -> bool;
     fn to_digit(self, radix: u32) -> Option<u32>;