import { Primitive } from "../../types/types";
/**
 * Returns true if a **value** is not null or undefined.
 */
export declare function exists<T>(value: T | undefined | null): value is T;
/**
 * Returns true if a **value** is an array.
 */
export declare function isArray<T>(value: any): value is any[];
/**
 * Returns true if a **value** is a boolean primitive. Does *not* return true for wrapper objects.
 */
export declare function isBoolean(value: any): value is boolean;
/**
 * Returns true if a **value** is not undefined.
 */
export declare function isDefined<T>(value: T | undefined): value is T;
/**
 * Returns true if a **value** is an error.
 */
export declare function isError(value: any): value is Error;
/**
 * Returns true if a **value** is considered a function.
 */
export declare function isFunction(value: any): value is Function;
/**
 * Returns true if a **value** is null.
 */
export declare function isNull(value: any): value is null;
/**
 * Returns true if a **value** is a number primitive. Does *not* return true for wrapper objects.
 */
export declare function isNumber(value: any): value is number;
/**
 * Returns true if a **value** is not null.
 */
export declare function isntNull<T>(value: T | null): value is T;
/**
 * Returns true if a **value** is an object.
 */
export declare function isObject(value: any): value is object;
/**
 * Returns true if a **value** is a primitive. Does *not* return true for wrapper objects.
 */
export declare function isPrimitive(value: any): value is Primitive;
/**
 * Returns true if a **value** is a regular expression object.
 */
export declare function isRegularExpression(value: any): value is RegExp;
/**
 * Returns true if a **value** is a string primitive. Does *not* return true for wrapper objects.
 */
export declare function isString(value: any): value is string;
/**
 * Returns true if a **value** is a symbol primitive. Does *not* return true for wrapper objects.
 */
export declare function isSymbol(value: any): value is Symbol;
/**
 * Returns true if a **value** is undefined.
 */
export declare function isUndefined(value: any): value is undefined;
/**
 * Returns true if a **value** is null or undefined.
 */
export declare function missing<T>(value: T | undefined | null): value is null | undefined;