Enum Assert 

pub enum Assert<const COND: OperationPossibility> {}

The helper type allowing to restrict the const generic input parameters

Usage example. Allow myfunction only for positive values of SOME_PARAM:

#![feature(generic_const_exprs)]
#![feature(adt_const_params)]

const fn myfunction_allowed(some_param: i32) -> OperationPossibility {
    allow_if(some_param>0)
}

fn myfunction<const SOME_PARAM: i32>()
where Assert<{myfunction_allowed(SOME_PARAM)}>: IsAllowed,
{
   // code
}

Trait Implementations

impl IsAllowed for Assert<{ OperationPossibility::Allowed }>