Clarify documentation of slice sorting methods

Author: Lionelf329

library/core/src/slice/mod.rs

@@ -2100,9 +2100,11 @@ impl<T> [T] {
     ///
     /// If the value is found then [`Result::Ok`] is returned, containing the
     /// index of the matching element. If there are multiple matches, then any
-    /// one of the matches could be returned. If the value is not found then
-    /// [`Result::Err`] is returned, containing the index where a matching
-    /// element could be inserted while maintaining sorted order.
+    /// one of the matches could be returned. The index is chosen
+    /// deterministically, but is subject to change in future versions of Rust.
+    /// If the value is not found then [`Result::Err`] is returned, containing
+    /// the index where a matching element could be inserted while maintaining
+    /// sorted order.
     ///
     /// See also [`binary_search_by`], [`binary_search_by_key`], and [`partition_point`].
     ///
@@ -2153,9 +2155,11 @@ impl<T> [T] {
     ///
     /// If the value is found then [`Result::Ok`] is returned, containing the
     /// index of the matching element. If there are multiple matches, then any
-    /// one of the matches could be returned. If the value is not found then
-    /// [`Result::Err`] is returned, containing the index where a matching
-    /// element could be inserted while maintaining sorted order.
+    /// one of the matches could be returned. The index is chosen
+    /// deterministically, but is subject to change in future versions of Rust.
+    /// If the value is not found then [`Result::Err`] is returned, containing
+    /// the index where a matching element could be inserted while maintaining
+    /// sorted order.
     ///
     /// See also [`binary_search`], [`binary_search_by_key`], and [`partition_point`].
     ///
@@ -2224,9 +2228,11 @@ impl<T> [T] {
     ///
     /// If the value is found then [`Result::Ok`] is returned, containing the
     /// index of the matching element. If there are multiple matches, then any
-    /// one of the matches could be returned. If the value is not found then
-    /// [`Result::Err`] is returned, containing the index where a matching
-    /// element could be inserted while maintaining sorted order.
+    /// one of the matches could be returned. The index is chosen
+    /// deterministically, but is subject to change in future versions of Rust.
+    /// If the value is not found then [`Result::Err`] is returned, containing
+    /// the index where a matching element could be inserted while maintaining
+    /// sorted order.
     ///
     /// See also [`binary_search`], [`binary_search_by`], and [`partition_point`].
     ///