import type { SchemaOptions } from "./Schema.js";
import { Schema } from "./Schema.js";
/** Allowed options for `BooleanSchema` */
export interface BooleanSchemaOptions extends SchemaOptions {
    readonly value?: boolean | undefined;
    readonly required?: boolean | undefined;
}
/** Define a valid boolean. */
export declare class BooleanSchema extends Schema<boolean> {
    readonly value: boolean;
    readonly required: boolean;
    constructor({ value, required, ...options }: BooleanSchemaOptions);
    validate(unsafeValue?: unknown): boolean;
    format(value: boolean): string;
}
/** Valid boolean. */
export declare const BOOLEAN: BooleanSchema;