Then im not really sure what your point is, because I've written zig code that reuses code in a similar way to what you are talking about, with three different

Then im not really sure what your point is, because I've written zig code that reuses code in a similar way to what you are talking about, with three different forms of parallelism calling into some common runner code each of which has different needs for resource cleanup times (single threaded, cooperative, and independent parallelism). It wasn't a problem. Have you tried doing what you propose in zig? Ultimately, the only difference between a .deinit() and a destructor is that one is explicit and the other is not. There are cases where you can easily make a mistake for both an explicit destructor and an implicit destructor.