Fix typo

crates/stdx/src/lib.rs

@@ -5,7 +5,7 @@ use std::{cell::Cell, fmt};
 /// Appends formatted string to a `String`.
 #[macro_export]
 macro_rules! format_to {
-    (&buf:expr) => ();
+    ($buf:expr) => ();
     ($buf:expr, $lit:literal $($arg:tt)*) => {
         { use ::std::fmt::Write as _; let _ = ::std::write!($buf, $lit $($arg)*); }
     };