import type { ValidationIssue } from "../Decorator/ValidationIssue";
import { type Result } from "../Error/safeExecute";
/**
 * Validates every decorated field of an instance and aggregates the failures.
 * Reads the rules registered by the field decorators along the prototype
 * chain, so inherited rules are included.
 *
 * @template T - The instance type.
 * @param instance - The object to validate.
 * @returns A success {@link Result} carrying the instance when every field is
 * valid, otherwise an error {@link Result} carrying one issue per failing
 * field.
 *
 * @example
 * ```typescript
 * class User {
 *   @IsString name = "alice";
 *   @IsNumber age = 20;
 * }
 * const result = validateInstance(new User());
 * if (result.type === "error") {
 *   console.log(result.error);
 * }
 * ```
 */
export declare const validateInstance: <T extends object>(instance: T) => Result<T, ValidationIssue[]>;