/**
 * Same as `jsonSizeFast`, but for MessagePack.
 *
 * - Allows Buffers or Uint8Arrays a MessagePack `bin` values. Adds 5 bytes overhead for them.
 * - Allows embedded `JsonPackValue` values.
 * - Allows MessagePack `JsonPackExtension` extensions. Adds 6 bytes overhead for them.
 *
 * @param value MessagePack value, which can contain binary data, extensions and embedded MessagePack.
 * @returns Approximate size of the value in bytes.
 */
export declare const msgpackSizeFast: (value: unknown) => number;