type Func<Args extends unknown[], Return> = (...args: Args) => Return;
interface CallableInstanceConstructor {
    new <Args extends unknown[], Return>(property: string | symbol): Func<Args, Return> & CallableInstance<Args, Return>;
    readonly prototype: CallableInstance<any, any>;
}
interface CallableInstance<Args extends unknown[], Return> extends Function {
    (...args: Args): Return;
}
declare const CallableInstance: CallableInstanceConstructor;

/**
 * Check if given payload is a plain object
 * "Plain object" means it is not an instance of any class or built-in type,
 * or just like Record<string, any> in TypeScript.
 */
declare function isPlainObject(payload: any): payload is Record<string, any>;

export { CallableInstance as C, isPlainObject as i };