AFAI, we didn't have these before, but when Andrei removed the dependencies, code that used to look "simple" (`version (assert) if (condition) throw new RangeError();`) suddenly became much more involved:
```D
version (assert)
{
    import core.exception : RangeError;
    throw new RangeError();
}
```
I think placing the code in a precondition cleans it up somewhat (removes the `version (assert)`), and arguably, is more correct.

But if you have any ideas on specific details, I'm all ears. But once you've opened your in block, the code inside is just trivial and boilerplate. I'm not entirely sure how `rageEnforce` would work/help. But I'd love to be proven wrong.