import type { SchemaValue } from '../schema.js';
import { type ValueConfig } from './value.js';
type BooleanValueConfig = ValueConfig<boolean>;
export declare class BooleanValue implements SchemaValue<boolean> {
    private value;
    constructor(config?: BooleanValueConfig);
    validate(value: boolean): "value is required." | "value is not a boolean." | null;
    get default(): boolean | undefined;
    get required(): boolean;
}
export declare function isBooleanOrUndefined(value: unknown): value is undefined | boolean;
export declare function isBoolean(value: unknown): value is boolean;
export {};