let to_string = |b: bytes| -> Result<string, `EncodingError(string)> 'core_bytes_to_string;
let to_string_lossy = |b: bytes| -> string 'core_bytes_to_string_lossy;
let from_string = |s: string| -> bytes 'core_bytes_from_string;
let concat = |@args: [bytes, Array<bytes>]| -> bytes 'core_bytes_concat;
let to_array = |b: bytes| -> Array<u8> 'core_bytes_to_array;
let from_array = |a: Array<u8>| -> bytes 'core_bytes_from_array;
let len = |b: bytes| -> u64 'core_bytes_len;
let encode = |spec: Array<Encode>| -> bytes 'core_buffer_encode;
let decode = |buf: bytes, spec: Array<Decode>| -> Result<bytes, `DecodeError(string)> 'core_buffer_decode