if_chain! {
    if let Expr_::ExprCast(ref expr, ref cast_ty) = stmt.node;
    if let Ty_::TyPath(ref qp) = cast_ty.node;
    if match_qpath(qp, &["char"]);
    if let Expr_::ExprLit(ref lit) = expr.node;
    if let LitKind::Int(69, _) = lit.node;
    then {
        // report your lint here
    }
}