import { Temporal } from "@js-temporal/polyfill";
import type { Overflow } from "../../types/index.js";
/**
 * Return a PlainDateTime ISO string with the given `fields` set on `value`.
 *
 * - Wraps `Temporal.PlainDateTime.prototype.with()`, which resolves every supplied field in a
 *   single atomic overflow pass — see `setDate`'s doc for why that matters over composing
 *   `addDateTime()` calls field-by-field.
 * - `fields` may set any of `year`, `month`, `monthCode`, `day`, `hour`, `minute`, `second`,
 *   `millisecond`, `microsecond`, `nanosecond`, `era`, and/or `eraYear`; omitted fields keep
 *   their current value. An empty object is a no-op.
 * - Returns "" for invalid input.
 *
 * `overflow` ("constrain" (default) | "reject") controls out-of-range results, e.g. setting
 * `month: 2` on a datetime whose `day` is 31: "constrain" clamps to Feb 29/28, "reject" throws
 * (resulting in "").
 *
 * @param value ISO PlainDateTime string
 * @param fields Partial<Temporal.PlainDateTimeLike> object specifying fields to set
 * @param options optional: overflow ("constrain" | "reject")
 * @returns ISO PlainDateTime string with fields set, or "" on invalid input
 *
 * @example setDateTime("2024-03-10T12:00:00", { hour: 9 }) // "2024-03-10T09:00:00"
 * @example setDateTime("2024-01-31T12:00:00", { month: 2 }) // "2024-02-29T12:00:00" (constrain clamps to the last valid day)
 * @example setDateTime("2024-01-31T12:00:00", { month: 2 }, { overflow: "reject" }) // ""
 * @example setDateTime("2024-03-10T12:00:00", {}) // "2024-03-10T12:00:00" (empty fields object is a no-op)
 * @example setDateTime("invalid", { hour: 9 }) // ""
 */
export declare function setDateTime(value: string, fields: Omit<Temporal.PlainDateTimeLike, "calendar">, options?: {
    overflow?: Overflow;
}): string;