/**
 * 判断是否为纯对象
 */
export declare function isPlainObject(target: any): target is Record<PropertyKey, any>;
/**
 * 判断是否为对象
 */
export declare function isObject(target: any): target is Record<PropertyKey, any>;
/**
 * 判断是否为函数
 */
export declare function isFunction(target: any): target is (...args: any[]) => any;
/**
 * 判断是否为字符串
 */
export declare function isString(target: any): target is string;
/**
 * 判断是否为数值
 */
export declare function isNumber(target: any): target is number;
/**
 * 判断是否为布尔值
 */
export declare function isBoolean(target: any): target is boolean;
/**
 * 判断是否为 undefined
 */
export declare function isUndefined(target: any): target is undefined;
/**
 * 判断是否为 null 或者 undefined
 */
export declare function isNullish(target: any): target is null | undefined;
/**
 * 判断是否为原始类型
 */
export declare function isPrimitive(target: any): target is string | number | boolean;
/**
 * 判断是否为空，包括空数组和空字符串
 */
export declare function isEmpty(target: any): boolean;
/**
 * 判断是否为类Promise对象
 */
export declare function isThenable(target: any): target is PromiseLike<any>;