Describe the enhancement requested In various conditions it would be helpful to be able to generate boolean masks that point to specific indices of an array. For example it can be combined with ...

The boolean 'true' will happily undergo integer promotion, and so the expression makes perfectly good sense. It's just that it will give the value 'false' when x is, say, 2.

gh-17538 was merged to add more C++/pybind11-backed distance metrics, leading to a net-positive situation with performance of those metrics, but a few modest regressions for a subset of bool ...