/**
 * Comparison methods may return a boolean, a promise, or a generator.
 * Operators yield the result, so sync implementations stay valid and async
 * `valueOf()` can be awaited with `yield`.
 */
export type ComparableResult = boolean | Promise<boolean> | Generator<unknown, boolean, any>;
export interface Comparable {
    equals: (rhs: any) => ComparableResult;
    gt: (rhs: any) => ComparableResult;
    geq: (rhs: any) => ComparableResult;
    lt: (rhs: any) => ComparableResult;
    leq: (rhs: any) => ComparableResult;
}
export declare function isComparable(arg: any): arg is Comparable;