小编Unb*_*T26的帖子

当我们需要一个依赖于特征中其他类型的类型时，我们如何克服关联类型默认值的问题？

    trait Foo{
        type C;
        type K = Vec<Self::C>;
    }

error[E0658]: associated type defaults are unstable
  |
3 |     type K = Vec<Self::C>;
  |     ^^^^^^^^^^^^^^^^^^^^^^
  |
   = note: see issue #29661 <https://github.com/rust-lang/rust/issues/29661> for more information