How is it wrt to code size and RAM size? Would you be able to do anything interesting on e.g. an STM32F103C8 Cortex M3 with 64kByte Flash and 20kByte RAM? How hard is it to revive iterators without std? Iterators seem very useful for signal processing and handling communication protocols. Would it be wise to take this into production at this point?
The Iterator traits are libcore features - just the implementation is libstd. Have a look at iterator.rs - it is not all too long.
I don’t have any experience with such systems, but core never allocates and from there on, it should be possible to write a std replacement that fits your usecase better.