Auto merge of #97622 - JohnTitor:rollup-4qoxrjn, r=JohnTitor

Rollup of 9 pull requests

Successful merges:

 - #94647 (Expose `get_many_mut` and `get_many_unchecked_mut` to HashMap)
 - #97216 (Ensure we never consider the null pointer dereferencable)
 - #97399 (simplify code of finding arg index in `opt_const_param_of`)
 - #97470 (rustdoc: add more test coverage)
 - #97498 (Corrected EBNF grammar for from_str)
 - #97562 (Fix comment in `poly_project_and_unify_type`)
 - #97580 (Add regression test for #71546)
 - #97611 (Tweak insert docs)
 - #97616 (Remove an unnecessary `Option`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 3 insertions, 2 deletions

diff --git a/compiler/rustc_data_structures/src/sso/set.rs b/compiler/rustc_data_structures/src/sso/set.rs
index f71522d3714..4fda3adb7b8 100644
--- a/compiler/rustc_data_structures/src/sso/set.rs
+++ b/compiler/rustc_data_structures/src/sso/set.rs
@@ -126,9 +126,10 @@ impl<T: Eq + Hash> SsoHashSet<T> {
 
     /// Adds a value to the set.
     ///
-    /// If the set did not have this value present, `true` is returned.
+    /// Returns whether the value was newly inserted. That is:
     ///
-    /// If the set did have this value present, `false` is returned.
+    /// - If the set did not previously contain this value, `true` is returned.
+    /// - If the set already contained this value, `false` is returned.
     #[inline]
     pub fn insert(&mut self, elem: T) -> bool {
         self.map.insert(elem, ()).is_none()