export declare const isString: (v: any) => v is string;
export declare const isNotString: <V extends unknown>(v: V) => v is Exclude<V, string>;
export declare const isNumber: (v: any) => v is number;
export declare const isNotNumber: <V extends unknown>(v: V) => v is Exclude<V, number>;
export declare const isUndefined: (v: any) => v is undefined;
export declare const isDefined: <V extends unknown>(v: V) => v is Exclude<V, undefined>;
export declare const isNull: (v: any) => v is null;
export declare const isNotNull: <V extends unknown>(v: V) => v is Exclude<V, null>;
export declare const isNil: (v: any) => v is null | undefined;
export declare const isError: (v: any) => v is Error;