type KeyOf<S, Q> = keyof (S & Q);
/**
 * Container for URL query parameters with typed accessors.
 * Supports initialization from multiple formats (string, array, object, URLSearchParams).
 *
 * @template QuerySchema Known query parameter keys and their expected value types.
 */
export default class IncomingSearchParams<QuerySchema extends Record<string, string> = Record<string, string>> {
    #private;
    /**
     * Read any known query parameter as a string or null.
     */
    getAny: <T extends KeyOf<QuerySchema, any>>(key: T) => string | null;
    /**
     * Constructs a new IncomingSearchParams instance.
     *
     * @param init initial parameters
     */
    constructor(init?: string | string[][] | Record<string, string> | URLSearchParams);
    /**
     * Returns a JSON-like object of parameters, taking the first value for each key.
     * @returns object mapping each key to its first value.
     */
    json(): QuerySchema;
    /**
     * Retrieves the first value for a known parameter or null if missing.
     *
     * @param key parameter key to retrieve.
     * @returns first parameter value or null.
     */
    getKnown<T extends keyof QuerySchema>(key: T): QuerySchema[T] | null;
    /**
     * Retrieves all values for a known parameter key.
     *
     * @param key parameter key to retrieve.
     * @returns array of all values for the key.
     */
    getAll<T extends keyof QuerySchema>(key: T): string[];
    /**
     * Checks if a known parameter key is present.
     *
     * @param key parameter key to check.
     * @returns true if the key exists.
     */
    has<T extends keyof QuerySchema>(key: T): boolean;
    /**
     * Sets a parameter to a single value, replacing existing values.
     *
     * @param key parameter key to set.
     * @param value value to assign.
     * @returns instance for chaining.
     */
    set<T extends keyof QuerySchema>(key: T, value: any): this;
    /**
     * Appends a value to a parameter key, preserving existing values.
     *
     * @param key parameter key to append to.
     * @param value value to append.
     * @returns instance for chaining.
     */
    append<T extends keyof QuerySchema>(key: T, value: any): this;
    /**
     * Deletes all values for a parameter key.
     *
     * @param key parameter key to delete.
     * @returns instance for chaining.
     */
    delete<T extends keyof QuerySchema>(key: T): this;
    /**
     * Returns a simple object of parameters taking the first value for each key.
     *
     * @returns plain object of key->firstValue.
     */
    getObject(): Record<string, string>;
    /**
     * Iterator over [key, value] pairs for each parameter value.
     * Works like URLSearchParams[Symbol.iterator].
     */
    [Symbol.iterator](): IterableIterator<[string, string]>;
}
export {};