/// <reference types="bn.js" />
import type { HexString, NumberOptions, ToBn } from '../types.js';
import type { BN } from './bn.js';
/**
 * @name bnToHex
 * @summary Creates a hex value from a BN.js bignumber object.
 * @description
 * `null` inputs returns a `0x` result, BN values return the actual value as a `0x` prefixed hex value. Anything that is not a BN object throws an error. With `bitLength` set, it fixes the number to the specified length.
 * @example
 * <BR>
 *
 * ```javascript
 * import BN from 'bn.js';
 * import { bnToHex } from '@polkadot/util';
 *
 * bnToHex(new BN(0x123456)); // => '0x123456'
 * ```
 */
export declare function bnToHex<ExtToBn extends ToBn>(value?: ExtToBn | BN | bigint | number | null, { bitLength, isLe, isNegative }?: NumberOptions): HexString;