import type { Failure, Result, Success } from './result.ts';
export declare function isProperty<T extends object>(object: T, name: string): name is Extract<keyof T, string>;
export declare function isFunction(value: unknown): value is (...args: [unknown]) => unknown;
export declare function isNull(value: unknown): boolean;
export declare function isNumber(value: unknown): value is number;
export declare function isObject(value: unknown): value is object;
export declare function isString(value: unknown): value is string;
export declare function isUndefined(value: unknown): value is undefined;
export declare function isFailure<T>(result: Result<T>): result is Failure;
export declare function isSuccess<T>(result: Result<T>): result is Success<T>;