export declare const isUndefined: (val: unknown) => val is undefined;
export declare const isBoolean: (val: unknown) => val is boolean;
export declare const isNumber: (val: unknown) => val is number;
export declare const isString: (val: unknown) => boolean;
export declare const isObject: (val: unknown) => boolean;
export declare const isArray: (val: unknown) => "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function";
export declare const isEmpty: (val: unknown) => boolean;
export declare const isElement: (e: unknown) => e is Element;
export declare const isStringNumber: (val: string) => boolean;