{"ast_node_type":"other","tokens":[{"end":51,"kind":"keyword","start":0,"text":"self.try_eval_target_usize(tcx,"}]}
        self.try_eval_target_usize(tcx, typing_env)
    pub fn eval_target_usize(self, tcx: TyCtxt<'tcx>, typing_env: ty::TypingEnv<'tcx>) -> u64 {
            .unwrap_or_else(|| bug!("expected usize, got {:#?}", self))