title: kotlin - Type mismatch: inferred type is MutableList<TypeA> but MutableList<InterfaceType> was expected
body: <p>I'm trying to code some stuff in kotlin but I have some problem with that. How can i achieve this problem?  I share my code.. Please help me!</p>
  
  <pre><code>interface InterfaceType {}
  
  open class ConcreteImpl: InterfaceType {}
  
  class TypeA: ConcreteImpl() {}
  
  fun test() {
  
      var interfaceTypeList: MutableList&lt;InterfaceType&gt; = mutableListOf()
  
      var typeAList: MutableList&lt;TypeA&gt; = mutableListOf()
  
      interfaceTypeList = typeAList
  
  }
  </code></pre>
  
  <p><a href="https://pl.kotl.in/MxlEaG3vr" rel="nofollow noreferrer">You can show the code from here.</a></p>