import "../_dnt.polyfills.js";
export interface Guard<T, Y extends T> {
    (value: T): value is Y;
}
export declare function is(guard: undefined): Guard<unknown, undefined>;
export declare function is(guard: null): Guard<unknown, null>;
export declare function is(guard: typeof Number): Guard<unknown, number>;
export declare function is(guard: typeof String): Guard<unknown, string>;
export declare function is(guard: typeof Boolean): Guard<unknown, boolean>;
export declare function is(guard: typeof BigInt): Guard<unknown, bigint>;
export declare function is(guard: typeof Symbol): Guard<unknown, symbol>;
export declare function is(guard: true): Guard<unknown, true>;
export declare function is(guard: false): Guard<unknown, false>;
export declare function is<T>(guard: abstract new (...args: any) => T): Guard<unknown, T>;
export declare function is<T extends string | {
    type: string;
}, U extends T extends {
    type: string;
} ? T["type"] : T>(guard: U): Guard<T, Extract<T, U | {
    type: U;
}>>;
export type SmartExclude<T1, T2 extends T1> = T2 extends null | undefined ? T1 & Exclude<{} | null | undefined, T2> : Exclude<T1, T2>;