import { Infer } from '../types.js';
import XVType from '../XVType.js';

type Func<A extends XVType<any>[], R extends XVType<any>, Async extends boolean = false> = Async extends true ? (...args: {
    [K in keyof A]: Infer<A[K]>;
}) => Promise<Infer<R>> : (...args: {
    [K in keyof A]: Infer<A[K]>;
}) => Infer<R>;
type XVFunctionOptions<A extends XVType<any>[], R extends XVType<any>> = {
    args: A;
    returns: R;
    async?: boolean;
};
declare class XVFunction<A extends XVType<any>[], R extends XVType<any>, Async extends boolean = false> extends XVType<Func<A, R, Async>> {
    readonly func_args: A;
    readonly func_return: R;
    readonly is_async: Async;
    constructor(options: XVFunctionOptions<A, R>);
    protected check(value: unknown): Func<A, R, Async>;
    parse(fn: unknown): Func<A, R, Async> | undefined | null;
}

export { XVFunction as default };
export type { XVFunctionOptions };