syntax - Mix 不支持 .pick？

Question

我正在尝试这个:

 my Mix $mix = { foo => 3.5, bar => 2.5}.Mix; 
 say $mix.pick

理论上这应该有效，因为 a Mix does Baggy ，和Baggy does pick 。但是，我收到错误:

.pick is not supported on a Mix

知道为什么不支持它吗？我应该使用什么替代方案？

Answer 1

Any idea why it's not supported?

也许:

lizmat     TimToady: .pick($n > 1) on a MixHash, how would that work? I assume it won't work? What to deduct for a chosen key?
lizmat     (or on a Mix, for that matter)
TimToady   I don't we need to support .pick on a Mix until someone comes up with a real use case

来自http://colabti.org/irclogger/irclogger_log/perl6?date=2013-10-03#l1369

What alternative should I use?

我怀疑这是“自己写的”。