import type { PrototypeStruct } from '../index.js';
declare type RetainPredicate = (character: string) => boolean;
interface Retain {
    retain(predicate: RetainPredicate): string;
}
export declare const retain: PrototypeStruct;
declare global {
    interface String extends Retain {
    }
}
export {};
//# sourceMappingURL=retain.d.ts.map