Permutation Maps: zip+sort with indirection

At ACCU on Sea 2026 I sat in on Nicolai Josuttis’ talk Taming C++23: The things about C++23 you do not know. One of his examples was the zip+sort: sorting two separate collections together by zipping them and sorting on a projection. It’s a very good demonstration of how std::views::zip and the ranges algorithms compose. It also reminded me of a pattern I’ve now reached for and used in two dif...