import { Literal, Schemable1, WithRefine1, WithUnion1, WithUnknownContainers1 } from './Schemable';
/**
 * @category model
 * @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;
/**
 * @category constructors
 * @since 2.2.0
 */
export declare const literal: <A extends readonly [Literal, ...Literal[]]>(...values: A) => Guard<A[number]>;
/**
 * @category primitives
 * @since 2.2.0
 */
export declare const string: Guard<string>;
/**
 * Note: `NaN` is excluded.
 *
 * @category primitives
 * @since 2.2.0
 */
export declare const number: Guard<number>;
/**
 * @category primitives
 * @since 2.2.0
 */
export declare const boolean: Guard<boolean>;
/**
 * @category primitives
 * @since 2.2.0
 */
export declare const UnknownArray: Guard<Array<unknown>>;
/**
 * @category primitives
 * @since 2.2.0
 */
export declare const UnknownRecord: Guard<Record<string, unknown>>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const refine: <A, B extends A>(refinement: (a: A) => a is B) => (from: Guard<A>) => Guard<B>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const nullable: <A>(or: Guard<A>) => Guard<A | null>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const type: <A>(properties: { [K in keyof A]: Guard<A[K]>; }) => Guard<{ [K_1 in keyof A]: A[K_1]; }>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const partial: <A>(properties: { [K in keyof A]: Guard<A[K]>; }) => Guard<Partial<{ [K_1 in keyof A]: A[K_1]; }>>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const record: <A>(codomain: Guard<A>) => Guard<Record<string, A>>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const array: <A>(items: Guard<A>) => Guard<A[]>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const tuple: <A extends readonly unknown[]>(...components: { [K in keyof A]: Guard<A[K]>; }) => Guard<A>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const intersect: <B>(right: Guard<B>) => <A>(left: Guard<A>) => Guard<A & B>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const union: <A extends readonly [unknown, ...unknown[]]>(...members: { [K in keyof A]: Guard<A[K]>; }) => Guard<A[number]>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const sum: <T extends string>(tag: T) => <A>(members: { [K in keyof A]: Guard<A[K]>; }) => Guard<A[keyof A]>;
/**
 * @category combinators
 * @since 2.2.0
 */
export declare const lazy: <A>(f: () => Guard<A>) => Guard<A>;
/**
 * @category instances
 * @since 2.2.0
 */
export declare const URI = "io-ts/Guard";
/**
 * @category instances
 * @since 2.2.0
 */
export declare type URI = typeof URI;
declare module 'fp-ts/es6/HKT' {
    interface URItoKind<A> {
        readonly [URI]: Guard<A>;
    }
}
/**
 * @category instances
 * @since 2.2.3
 */
export declare const schemableGuard: Schemable1<URI> & WithUnknownContainers1<URI> & WithUnion1<URI> & WithRefine1<URI>;