/**
 * @since 2.2.0
 */
import { Literal, Schemable1, WithRefinement1, WithUnion1, WithUnknownContainers1 } from './Schemable';
/**
 * @since 2.2.0
 */
export interface Guard<A> {
    is: (u: unknown) => u is A;
}
/**
 * @since 2.2.2
 */
export declare type TypeOf<G> = G extends Guard<infer A> ? A : never;
/**
 * @since 2.2.0
 */
export declare function literal<A extends ReadonlyArray<Literal>>(...values: A): Guard<A[number]>;
/**
 * @since 2.2.0
 */
export declare const never: Guard<never>;
/**
 * @since 2.2.0
 */
export declare const string: Guard<string>;
/**
 * @since 2.2.0
 */
export declare const number: Guard<number>;
/**
 * @since 2.2.0
 */
export declare const boolean: Guard<boolean>;
/**
 * @since 2.2.0
 */
export declare const UnknownArray: Guard<Array<unknown>>;
/**
 * @since 2.2.0
 */
export declare const UnknownRecord: Guard<Record<string, unknown>>;
/**
 * @since 2.2.0
 */
export declare function refinement<A, B extends A>(from: Guard<A>, refinement: (a: A) => a is B): Guard<B>;
/**
 * @since 2.2.0
 */
export declare function nullable<A>(or: Guard<A>): Guard<null | A>;
/**
 * @since 2.2.0
 */
export declare function type<A>(properties: {
    [K in keyof A]: Guard<A[K]>;
}): Guard<{
    [K in keyof A]: A[K];
}>;
/**
 * @since 2.2.0
 */
export declare function partial<A>(properties: {
    [K in keyof A]: Guard<A[K]>;
}): Guard<Partial<{
    [K in keyof A]: A[K];
}>>;
/**
 * @since 2.2.0
 */
export declare function record<A>(codomain: Guard<A>): Guard<Record<string, A>>;
/**
 * @since 2.2.0
 */
export declare function array<A>(items: Guard<A>): Guard<Array<A>>;
/**
 * @since 2.2.0
 */
export declare function tuple<A extends ReadonlyArray<unknown>>(...components: {
    [K in keyof A]: Guard<A[K]>;
}): Guard<A>;
/**
 * @since 2.2.0
 */
export declare function intersection<A, B>(left: Guard<A>, right: Guard<B>): Guard<A & B>;
/**
 * @since 2.2.0
 */
export declare function union<A extends ReadonlyArray<unknown>>(...members: {
    [K in keyof A]: Guard<A[K]>;
}): Guard<A[number]>;
/**
 * @since 2.2.0
 */
export declare function sum<T extends string>(tag: T): <A>(members: {
    [K in keyof A]: Guard<A[K]>;
}) => Guard<A[keyof A]>;
/**
 * @since 2.2.0
 */
export declare function lazy<A>(f: () => Guard<A>): Guard<A>;
/**
 * @since 2.2.0
 */
export declare const URI = "io-ts/Guard";
/**
 * @since 2.2.0
 */
export declare type URI = typeof URI;
declare module 'fp-ts/es6/HKT' {
    interface URItoKind<A> {
        readonly [URI]: Guard<A>;
    }
}
/**
 * @since 2.2.3
 */
export declare const schemableGuard: Schemable1<URI> & WithUnknownContainers1<URI> & WithUnion1<URI> & WithRefinement1<URI>;