pub fn is_unstable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Symbol> {
if tcx.is_const_fn_raw(def_id) {
let const_stab = tcx.lookup_const_stability(def_id)?;
- if const_stab.level.is_unstable() { Some(const_stab.feature) } else { None }
+ if const_stab.is_const_unstable() { Some(const_stab.feature) } else { None }
} else {
None
}