import type { Context } from 'hono';
/**
 * Creates a parameter decorator factory for route handlers
 * @template T - The type of the parameter value after transformation
 * @param type - The type identifier for the parameter
 * @param factory - Optional function to transform the parameter value
 * @returns A parameter decorator function that registers parameter metadata
 * @example
 * ```ts
 * const Body = createParamDecorator('body', async (data, ctx) => {
 *   const body = await ctx.req.json();
 *   return data ? body[data] : body;
 * });
 * ```
 */
export declare function createParamDecorator<T = any>(type: string, factory?: (data: any, ctx: Context) => T): (data?: any) => (target: Object, propertyKey: string | symbol, parameterIndex: number) => void;