import { AnyExpression } from '../../expressions';
import { ConstraintConfig } from '../../functions';
import { Type } from '../index';
export interface UnknownType<T = string, R extends boolean = boolean> extends Type<'UNKNOWN', R, T> {
    expression: AnyExpression<UnknownType<T, R>>;
    argument: this['input'] | this['expression'];
    required(conf?: ConstraintConfig): UnknownType<T, false>;
}