trait val _ValueType
fun box string() : String val
fun box value_of(
  s: String val)
: (Bool val | String val | I64 val | 
    U64 val | F64 val | _StringSeq val) ?
 fun box is_seq() : Bool val
fun box append(
  v1: (Bool val | String val | I64 val | 
    U64 val | F64 val | _StringSeq val),
  v2: (Bool val | String val | I64 val | 
    U64 val | F64 val | _StringSeq val))
: (Bool val | String val | I64 val | 
    U64 val | F64 val | _StringSeq val)
 
    © 2016-2018, The Pony Developers
© 2014-2015, Causality Ltd.
Licensed under the BSD 2-Clause License.
    https://stdlib.ponylang.io/cli-_ValueType