//@ known-bug: #136859 #![feature(generic_const_exprs)] trait If {} impl If for () {} trait IsZero { type Answer; } struct True; struct False; impl IsZero for () where (): If<{N == 0}> { type Msg = True; } trait Foobar {} impl Foobar for () where (): IsZero {} impl Foobar<{{ N }}> for () where (): IsZero {} fn main() {}