@reactivex/ix-esnext-esm/asynciterable/find.d.ts

export declare function find<T, S extends T>(source: AsyncIterable<T>, predicate: (value: T, index: number) => value is S, thisArg?: any): Promise<S | undefined>;
export declare function find<T>(source: AsyncIterable<T>, predicate: (value: T, index: number) => boolean | Promise<boolean>, thisArg?: any): Promise<T | undefined>;