I am the author of sosecrets-rs where right now, I am trying to write a RTSecret<T, MEC: typenum::Unsigned> struct where T is any type and MEC is an unsigned integer at the type level from the typenum crate (e.g. U69), etc. The crate counts the number of times (tracked by an internal counter of type…

It's possible write a macro that implements this as a lookup table on the number of bits in the typenum representation: use typenum::uint::{UTerm, UInt}; trait ChooseInt { type Output; } impl ChooseInt for UTerm { type Output = u8; } macro_rules! impl_choose_int { // Entry point …

Making a type level type function with `typenum` crate

help

jendrikw February 18, 2024, 7:42pm 3

Does this not work?

type CalcMinUIntType<N> = Shleft<U1, Add1<Log2<Length<N>>>>;
assert_type_eq!(CalcMinUIntType<U69>, U8);

2 Likes

`RTSecret<T, std::cell::Cell<u8>>` is the same size as `RTSecret<T, std::cell::Cell<u16>>`, why? And how to optimize such that former is smaller than latter?

As a library author, what should my `#![recursion_limit]` be?

Topic		Replies	Views
Drop as soon as possible	8	540	June 6, 2024
As a library author, what should my `#![recursion_limit]` be? help	2	534	May 23, 2024
How to serialize type-level information? E.g. to serialize generic type parameters of a struct help	9	435	May 3, 2024
Choosing the 'best' representation for unsigned integers at compile time	5	411	May 17, 2024
`RTSecret<T, std::cell::Cell<u8>>` is the same size as `RTSecret<T, std::cell::Cell<u16>>`, why? And how to optimize such that former is smaller than latter?	23	501	May 28, 2024

Making a type level type function with `typenum` crate

Related topics