Using types like i1, u24, or other nonstandard integer sizes.

[moonheart08]

LLVM itself supports arbitrary bitlength integers, however Rust does not. This would be useful for some less common, but still fairly normal cases, like 24-bit integers for emulating CPUs like the MC68000 (Some models use 24-bit address busses instead of 32-bit), or for memory constrained systems where you need all the space you can get, and as such packed bitfields are the best for storing data.

[cuviper]

There's a similar discussion here:
https://internals.rust-lang.org/t/pre-rfc-generic-integers-uint-n-and-int-n/7641

[programmerjake]

There is a postponed RFC: rust-lang/rfcs#2581

[programmerjake]

C is getting generic integers: rust-lang/rfcs#2581 (comment)

[darleybarreto]

Does it make sense to make a full featured PoC crate for integers of any size (<=128) and eventually merge into the compiler? Or something like that should be built directly inside of rustc from the ground up?