{"ast_node_type":"variable","tokens":[{"end":75,"kind":"keyword","start":0,"text":"let"}]}
                let val_ty = op.ty(bx.tcx(), lhs.layout.ty, rhs.layout.ty);
                );
                let operand_ty = Ty::new_tup(bx.tcx(), &[val_ty, bx.tcx().types.bool]);