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.
Sure if you ignore the most popular desktop OS in the world.
Also overcommit (at least how Linux does it) is dumb. It leads to broken OOM behaviour (killing a totally random process, or more often locking up the system and hard rebooting). And some apps do need to handle OOM properly, e.g. formal verification systems which can use enormous amounts of memory. Jasper has to resort to monitoring page fault stats to know when it is using too much memory.
For no_std style work where running out of memory is actually a hard limit, you have two choices:
1. disable the global allocator and use APIs that take Allocator, to force yourself to only consume APIs that can return errors from allocation. (The ergonomics aren't always great, and fattening all types with a pointer to Allocator isn't great; might be able to use a zero-sized Allocator, with trickery. Say goodbye to many libraries.)
2. use static analysis and try to avoid ever hitting a code path like Vec::with_capacity that doesn't return a Result. Make sure the tooling also analyses your dependencies. (Tooling for the static analysis is painful. And still, say goodbye to many libraries.)
I do wish there were more conveniences for alloc-can-fail APIs, like the failable version of Vec::push needs both try_reserve and push_within_capacity (nightly only).