syntax_data: {"ast_node_type":"other","tokens":[{"end":74,"kind":"keyword","start":0,"text":"ty::Const::new_expr(tcx,"}]}
source_snippet:             ty::Const::new_expr(tcx, Expr::new_unop(tcx, op, arg_ty, arg))
context_before:             let arg = recurse_build(tcx, body, arg, root_span)?;
context_after:         }