When sorting primitive types, without a sort_by function, sort and sort_unstable produce the same output (because the "identical elements" are themselves indistinguishable).

This change was done by hand ( #76541 ), and clippy will recommend changing sort to sort_unstable on primitive types.

However, if it is so useful it feels like it should be easy to do within the standard library itself, if there is a trait (or a trait was added) for primitive types.

This feel preferably to the current situation, where clippy tells users to change it, as then (see #76541 for example ), users have to keep adding comments to remind themselves that the sort_unstable is actually stable in this case.