Why bother? Most systems these days have over commit and so you can never get an out of memory error. The OS will happily give you more and more RAM, and then when you try to use that memory kill a program (may or not be your program). The only out of memory error you can see is if you are trying to allocate more memory than the address space allows. This is so unlikely that nobody considers it worth bother to try to handle.

It is important to try, for a few reasons. Among other things, increasing amounts of Rust written in the Linux kernel itself, and other environments where you need to take more care with memory allocation.

Rust as a language is capable of that. If you don't use the standard library then you can provide that functionality yourself. The standard library is trying to support it, without creating interfaces that are a massive pain to use.

For instance, it's easy for us to support `Vec::try_reserve`, and we do, but that's not trivial for users to use everywhere; it's error-prone, and it's easy to make a mistake and call a method that goes past your reservation. It's painful for us and for users to make `Vec::push` support this (and having a `try_` variant for every function), so we've been working on a better solution. One current possibility is to have a dedicated type for a Vec that has OOM handling, where `push` can return an error, so you know if you use that type you can never accidentally fail to handle OOM.