import type { CBORSchemaType } from "./type.js";
/**
 * Creates a schema for optional values that might be undefined
 *
 * @template T The type when the value is present
 * @param schema Schema for the value when present
 *
 * @example
 * ```typescript
 * import { cs } from "../cbor_schema.ts";
 * const optionalNumberSchema = cs.optional(cs.float);
 * const encoded1 = cs.toCBOR(optionalNumberSchema, 42);
 * const encoded2 = cs.toCBOR(optionalNumberSchema, undefined);
 * const decoded1 = cs.fromCBOR(optionalNumberSchema, encoded1); // 42
 * const decoded2 = cs.fromCBOR(optionalNumberSchema, encoded2); // undefined
 * ```
 */
export declare function optional<T>(schema: CBORSchemaType<T>): CBORSchemaType<T | undefined>;
//# sourceMappingURL=optional.d.ts.map