import { type StandardSchemaV1 } from "../../Validate/standardSchema";
export interface NullReturn {
    validate: boolean;
    message: string;
    type: "null";
}
/**
 * Wraps a validator to accept null values
 * @template T - The type of value the wrapped validator expects
 * @template R - The return type of the wrapped validator (preserved so the inner type tag flows through)
 * @param {Function} validator - Validator function to make nullable
 * @returns {Function} - Validator that passes for null or delegates to the wrapped validator
 */
export declare const nullable: <T, R extends {
    type: unknown;
    message: string;
    validate: boolean;
}>(validator: (value: T) => R) => ((value: T | null) => R | NullReturn) & StandardSchemaV1<T | null, T | null>;