import type { Option } from "../Option/index.js";
/**
* Atomically modifies the `FiberRef` with the specified partial function.
* If the function is undefined on the current value it returns the old value
* without changing it.
*/
export declare function updateSomeAndGet(f: (a: A) => Option): (fiberRef: import("./fiberRef.js").XFiberRef) => import("./excl-effect.js").IO;
//# sourceMappingURL=updateSomeAndGet.d.ts.map