/**
 * @file Guard Utilities
 * @description Type guards and validation utilities
 */
/**
 * Check if value is defined (not null or undefined)
 */
export declare function isDefined<T>(value: T | null | undefined): value is T;
/**
 * Check if value is null or undefined
 */
export declare function isNullish(value: unknown): value is null | undefined;
/**
 * Check if value is a string
 */
export declare function isString(value: unknown): value is string;
/**
 * Check if value is a non-empty string
 */
export declare function isNonEmptyString(value: unknown): value is string;
/**
 * Check if value is a number
 */
export declare function isNumber(value: unknown): value is number;
/**
 * Check if value is a finite number
 */
export declare function isFiniteNumber(value: unknown): value is number;
/**
 * Check if value is a boolean
 */
export declare function isBoolean(value: unknown): value is boolean;
/**
 * Check if value is a function
 */
export declare function isFunction(value: unknown): value is (...args: unknown[]) => unknown;
/**
 * Check if value is an object (not null, not array)
 */
export declare function isObject(value: unknown): value is Record<string, unknown>;
/**
 * Check if value is an array
 */
export declare function isArray<T = unknown>(value: unknown): value is T[];
/**
 * Check if value is a non-empty array
 */
export declare function isNonEmptyArray<T = unknown>(value: unknown): value is T[];
/**
 * Check if value is a Date
 */
export declare function isDate(value: unknown): value is Date;
/**
 * Check if value is a valid date string
 */
export declare function isDateString(value: unknown): value is string;
/**
 * Check if value is a Promise
 */
export declare function isPromise<T = unknown>(value: unknown): value is Promise<T>;
/**
 * Check if value matches a type guard
 */
export declare function assert<T>(value: unknown, guard: (value: unknown) => value is T, message?: string): asserts value is T;
/**
 * Check if value is one of allowed values
 */
export declare function isOneOf<T>(value: unknown, allowedValues: readonly T[]): value is T;
/**
 * Check if object has key
 */
export declare function hasKey<K extends string>(obj: unknown, key: K): obj is Record<K, unknown>;
/**
 * Check if object has all required keys
 */
export declare function hasKeys<K extends string>(obj: unknown, keys: readonly K[]): obj is Record<K, unknown>;
/**
 * Check if value is an Error
 */
export declare function isError(value: unknown): value is Error;
/**
 * Check if value is a valid email
 */
export declare function isEmail(value: unknown): value is string;
/**
 * Check if value is a valid URL
 */
export declare function isUrl(value: unknown): value is string;
/**
 * Check if value is a valid UUID
 */
export declare function isUuid(value: unknown): value is string;
/**
 * Narrow type or return undefined
 */
export declare function narrow<T>(value: unknown, guard: (value: unknown) => value is T): T | undefined;
/**
 * Narrow type or return default
 */
export declare function narrowOr<T>(value: unknown, guard: (value: unknown) => value is T, defaultValue: T): T;
/**
 * Create a type guard for object shape
 */
export declare function createShapeGuard<T extends Record<string, unknown>>(shape: {
    [K in keyof T]: (value: unknown) => value is T[K];
}): (value: unknown) => value is T;
/**
 * Safe JSON parse with type guard
 */
export declare function safeJsonParse<T>(json: string, guard: (value: unknown) => value is T): T | undefined;