import type { MessageExpressionPart } from '../formatted-parts.ts';
import type { MessageValue } from '../message-value.ts';
export interface MessageUnknownValue extends MessageValue<'unknown'> {
    readonly type: 'unknown';
    readonly source: string;
    readonly dir: 'auto';
    toParts(): [MessageUnknownPart];
    toString(): string;
    valueOf(): unknown;
}
/** @category Formatted Parts */
export interface MessageUnknownPart extends MessageExpressionPart<'unknown'> {
    type: 'unknown';
    value: unknown;
}
export declare const unknown: (source: string, input: unknown) => MessageUnknownValue;