Not sure if Rust should be promoted to build games, i prefer it being pushed to build mission critical software.
There is a very certain way rust is supposed to be used, which is a negative on it's own, but it will lead to a fulfilling and productive programming experience. (My opinion) If you need to regularly index something, then you're using the language wrong.
Long story short, yes, it's very different in game dev. It's very common to pre-allocate space for all your working data as large statically sized arrays because dynamic allocation is bad for performance. Oftentimes the data gets organized in parallel arrays (https://en.wikipedia.org/wiki/Parallel_array) instead of in collections of structs. This can save a lot of memory (because the data gets packed more densely) be more cache-friendly, and makes it much easier to make efficient use of SIMD instructions.
This is also fairly common in scientific computing (which is more my wheelhouse), and for the same reason: it's good for performance.
That seems like something that could very easily be turned into a compiler optimisation and enabled with something like an annotation. Would have some issue when calling across library boundaries ( a lot like the handling of gradual types), but within the codebase that'd be easy.
However this problem does still come up in iterator contexts. For example Iterator::take takes a usize.
Concrete example: pulling a single item out of a zip file, which supports random access, is O(1). Pulling a single item out of a *.tar.gz file, which can only be accessed by iterating it, is O(N).
