#![feature(generic_const_exprs)] #![allow(incomplete_features)] struct Bool<const B: bool>; trait True {} impl True for Bool<true> {} fn test<T, const P: usize>() where Bool<{core::mem::size_of::<T>() > 4}>: True { todo!() } fn main() { test::<2>(); //~^ ERROR function takes 2 generic arguments }