type OrFn<T> = (...args: T[]) => boolean;
type Arr = any[];
type OnceFn<A extends Arr, R> = (...args: A) => R;
type OnceCheckFn<A extends Arr> = (args: A) => boolean | undefined;
export declare function constant(): () => undefined;
export declare function constant<T>(v: T): () => T;
export declare const constTrue: () => true, constUndefined: () => undefined, noop: () => undefined, identity: <T>(obj: T) => T, or: <A, F extends OrFn<A>>(...fns: F[]) => (...args: A[]) => boolean;
export declare const once: <A extends Arr, R, F extends OnceFn<A, R> = OnceFn<A, R>>(fn: F, check?: OnceCheckFn<A>) => (...args: A) => any;
export declare const invoke: <T, A extends unknown[]>(fn: T | ((...args: A) => T), ...args: A) => T;
export {};