The following code does NOT compile:

#![feature(const_generics)]

struct Collatz<const N: Option<usize>>;

impl <const N: usize> Collatz<{Some(N)}> {
    
}

fn main() {
}

it errors with:

error[E0207]: the const parameter `N` is not constrained by the impl trait, self type, or predicates
 --> src/main.rs:5:13
  |
5 | impl <const N: usize> Collatz<{Some(N)}> {
  |             ^ unconstrained const parameter

However, when using normal generics in the places of the const generics, wrapping the T in an Option and sticking that into the Collatz struct does work:

struct Collatz<T>([T; 0]);

impl <T> Collatz<Option<T>> {}

Is it intended that const generic dont mimmic this behaviour?