/**
 * Throw Type Error
 */
export declare function error(expected: any, actual: unknown): never;
/**
 * Primitive Type Asserts
 */
export declare function isNull(x: unknown): asserts x is null;
export declare function isUndefined(x: unknown): asserts x is undefined;
export declare function isBoolean(x: unknown): asserts x is boolean;
export declare function isString(x: unknown): asserts x is string;
export declare function isNumber(x: unknown): asserts x is number;
export declare function isBigInt(x: unknown): asserts x is bigint;
export declare function isSymbol(x: unknown): asserts x is symbol;
export declare function isNotNullOrUndefined<T>(x: T): asserts x is NonNullable<T>;
export declare function isObject(x: unknown): asserts x is object;
/**
 * Standard Object Asserts
 */
export declare function isArray(x: unknown): asserts x is Array<unknown>;
export declare function isArrayOf(x: unknown, y: (x: unknown) => boolean): asserts x is Array<unknown>;
export declare function isObjectPropertyOf<P extends PropertyKey>(x: unknown, property: P): asserts x is {
    [K in P]: unknown;
};
export declare function areObjectPropertiesOf<P extends PropertyKey>(x: unknown, property: P[]): asserts x is {
    [K in P]: unknown;
};
/**
 * Literal Type Asserts
 */
export declare function isLiteral<T>(x: unknown, value: T): asserts x is typeof value;
export declare function isLiteralType<T>(x: unknown, set: Set<T>): asserts x is typeof set extends Set<infer T> ? T : never;