export type func<T> = () => T;
/**
 * Start promise with a function, which Promise.resolve() does not support.
 *
 * @param {T} value
 * - a value - which would be equivient to Promise.resolve(value)
 * - a function which will be called and pass the result in promise
 *
 * @return {Promise<T>}
 * A value within a promise
 *
 * @example
 * promiseThen(3)      // return 3 in a promise
 * promiseThen(()=>3)  // return 3 in a promise
 */
export default function then<T>(value: T | PromiseLike<T> | func<T>): Promise<T>;