Starting a paragraph about how to "safely" remove safeguards, and then tongue-in-cheek joking about Rust, kind of looks worse when your very first example isn't safe and liable to segfault even before the "proverbial gun" variant :)

It needs to be

> auto &lhs = *node_storage.emplace_back(make_unique(...));

instead of dereferencing lhs on the third line: emplace_back returns a reference to the inserted item, so it's a &unique_ptr...and that reference is invalidated by the rhs emplace_back reallocating the vector.

Rust also has a number of easy to use ways to do the same thing - slotmap or typed_arena are the standard, or just doing the vector indices scheme manually like at the bottom: this post is talking in circles around the fact the vector is really being used as an arena allocator without saying that, and so has obvious problems with it being extremely fragile to anyone who reads the type and expects it to be vector-like. It would probably do better explicitly saying that and linking to the wikipedia page or whatever, so the reader can look into the proper way of doing the code pattern.